Machine learning risk prediction of mortality for patients undergoing surgery with perioperative SARS-CoV-2: the COVIDSurg mortality score

Machine learning risk prediction of mortality for patients undergoing surgery with perioperative SARS-CoV-2: the COVIDSurg mortality score COVIDSurg Collaborative* ,† *Correspondence to: Mr Aneel Bhangu, NIHR Global Health Research Unit on Global Surgery, Heritage Building, University of Birmingham, Mindelsohn Way, Birmingham B15 2TH, UK (e-mail: [email protected]) † Members of the COVIDSurg Collaborative are co-authors of this article and are listed under the heading Collaborators. Introduction Since the beginning of the COVID-19 pandemic tens of millions of operations have been cancelled 1 as a result of excessive postoperative pulmonary complications (51.2 per cent) and mortality rates (23.8 per cent) in patients with perioperative SARS-CoV-2 infection 2 . There is an urgent need to restart surgery safely in order to minimize the impact of untreated non-communicable disease. As rates of SARS-CoV-2 infection in elective surgery patients range from 1–9 per cent 3–8 , vaccination is expected to take years to implement globally 9 and preoperative screening is likely to lead to increasing numbers of SARS-CoV-2-positive patients, perioperative SARS-CoV-2 infection will remain a challenge for the foreseeable future. To inform consent and shared decision-making, a robust, globally applicable score is needed to predict individualized mortality risk for patients with perioperative SARS-CoV-2 infection. The authors aimed to develop and validate a machine learningbased risk score to predict postoperative mortality risk in patients with perioperative SARS-CoV-2 infection. Methods Cohort study design An international, multicentre, prospective, cohort study (COVIDSurg Cohort Study) included consecutive patients who were diagnosed with SARS-CoV-2 in the 7 days before or the 30 days after surgery. Patients undergoing any type of surgery were included from 1 February 2020 to 31 July 2020. Full study methodology has been published previously 2 . Machine learning methods were used to analyse the COVIDSurg Cohort Study dataset. Sixteen patient and operative variables were entered into the analysis and, based on time, data were split into a derivation set, where all analysis and modelling were performed, and a validation set, where the final model was assessed. Five features were selected following variable importance measurements from both linear and non-linear modelling. These features were then combined into 26 different predictor sets, which were fitted through three different algorithms (logistic regression, decision trees and random forest), generating a total of 78 different models. These models were tuned with a 10-fold cross-validation, fitted in the 75 per cent split of the derivation set and assessed in the remaining 25 per cent. In order to ascertain the model’s stability, this training and testing split was randomly repeated 100 times (bootstraps). Finally, to decide which model to select, performance was evaluated through the mean area under the receiver operating characteristic curve (AUROC) value. A full description of methods is available in Appendix S1. Results Patients From 10 029 patients in the cohort study, data from 8492 patients entered the machine learning processes (Fig. 1). The most common surgical procedures were abdominal (40.6 per cent, 3446 of 8492 patients), orthopaedic (33.8 per cent, 2867 of 8492) and head and neck surgery (9.8 per cent, 835 of 8492). Emergency surgery accounted for 80.8 per cent (6862 of 8492 patients) and benign disease for 57.3 per cent (4868 of 8492) (Table S1). Of the 8492 patients, data from 6777 patients who had surgery from February to May 2020 (726 hospitals, 65 countries) were entered into the derivation set and data from 1715 who had surgery from June to July 2020 (296 hospitals, 53 countries) were entered into the validation set. Despite changes in patient demographics and treatment options, such as the recommendations from the RECOVERY trial 10 in June 2020, model performance remained robust between the derivation and validation sets. Mortality rates were 17.2 per cent overall (1462 of 8492 patients), 18.9 per cent (1279 of 6777) in the derivation set and 10.7 per cent (183 of 1715) in the validation set. Missing data handling is described in Appendix S2. Received: March 31, 2021. Accepted: April 26, 2021 V CThe Author(s) 2021. Published by Oxford University Press on behalf of BJS Society Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. 2BJS, 2021, 108, 1274–1292 DOI: 10.1093/bjs/znab183 Advance Access Publication Date: 6 July 2021 Rapid Research Communication Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Feature selection A full breakdown of feature and model selection are in Tables S3–S7. Random forest and elastic net were applied to the derivation set and the most important features were ranked (Fig. S1). Logit model performance of all different feature combination (runs) divided by each of the features is shown in Fig. 2a. The five features taken forward into model building were age, preoperative respiratory support, ASA grade, specialty and revised cardiac risk index (RCRI) score. Working data set Exploratory data analysis 16 candidate predictors Predictor excluded if missing 20% Missing values sensitivity analysis MICE imputation: n=8492 Complete cases: n= 8142 Split into derivation and validation sets Derivation set MICE n= 6777 Complete case analysis n= 6474 Feature selection Penalized logistic regression (EN) & random forest importance (m = 5) Testing and training split (25:75) Model generation RF, DT, GLM methods used to fit a model with each combination of the selected features Best performing feature combination and method selected Final model built (GLM) Validation Model deployment Web app Validation set MICE n= 1715 Complete case analysis n= 1668 • Split by time: derivation (February, March, April, May) and validation (June, July) • Elastic net modeling • Bootstrapping for hyperparameter optimization • Ranking of most important variables per model obtained and top 5 between both selected • Random split repeated 100 times (bootstrapping) • Hyperparameters optimization • All feature combinations separately modelied • Random forest (RF), decision tree (DT) generalized linear model (GLM) modeiling methods assessed Performance assessed through the mean and standard deviation of: • Sensitivity • Specificity • AUROC • Accuracy • Mean coefficients of all bootstrapped splits define the final model • Discrimination and calibration assessed • Imputed and non-imputed results compared • Case fatality percentages determined Excluded patients: Children n= 454 Local/other anaesthesia n= 389 Minor procedures (e.g. vessel catheterization) n= 272 Incomplete date of surgery n= 228 Not CT or swab confirmed diagnosis n= 186 Ambiguous gender n=8 CovidSurg n=10029 Fig. 1 Cohort study patient inclusion and model derivation and validation flow MICE, multiple imputation by chained equations; EN, elastic net. COVIDSurg Collaborative | 1275 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Model building and validation Multivariable models were built using all possible combinations of the five selected features, resulting in 26 model runs (Table S8). The smallest, higher-performing and most robust model was a logistic regression model with four features (age, ASA grade, RCRI score and preoperative respiratory support). A full description is in Appendix S2. The AUROC for the final score was 0.73 (95 per cent c.i. 0.71 to 0.74) in the derivation set and 0.80 (95 per cent c.i. 0.77 to 0.83) in the validation set (Fig. 2b).Calibrationinthevalidation set is shown in Fig. S2 (Brier score 0.084, intercept 0.078, slope 1.08). Mortality rates were studied for different probability risk cut-offs (Fig. S3), with a balance between distribution and clinical importance leading to cut-off values at approximately 2, 10, 30 and 45 per cent mortality. These showed high concordance between derivation and validation sets (Table S7)withthe final mortality percentages in the combined dataset being very similar. Deployment The COVIDSurg Mortality Score has been deployed online at http://covidsurgrisk.app/. Discussion Understanding risks related to SARS-CoV-2 and COVID-19 will remain important for the foreseeable future. There is an urgent need to restart elective surgery in order to reduce the backlog of cancelled operations 11 . Vaccination programmes are expected to take years to deliver, particularly in low- and middle-income countries 9 , and may not protect against new variants 12 . COVID- 19-free surgical pathways are unlikely to be universally implemented, particularly in emergency settings 3 , leaving patients at Age 1: Age, ASA grade 3: Age, Precperative respiratory support 2: Age, Revised Cardiac Risk Index 7: ASA grade, Speciality 5: ASA grade, Revised Cardiac Risk Index 4: Age, Speciality 6: ASA grade, Preoperative respiratory support 9: Revised Cardiac Risk Index, speciality 10: Preoperative respiratory support, Speciality 8: Revised Cardiac Risk Index, Preoperative respiratory support 12: Age, grade, Preoperative respiratory support 11: Age, ASA grade, Revised Cardiac Risk Index 13: Age, ASA grade, Speciality Model runs 16: Age, Preoperative respiratory support, Speciality 15: Age, Revised Cardiac Risk Index, Speciality 18: ASA grade, Revised Cardiac Risk Index, Speciality 19: ASA grade, Preoperative respiratory support, Speciality 17: ASA grade, Revised Cardiac Risk Index, Preoperative respiratory support 20: Revised Cardiac Risk Index, Preoperative respiratory support, Speciality 21: Age, ASA grade, Revised Cardiac Risk Index, Preoperative respiratory support 26: Age, ASA grade, Revised Cardiac Risk Index, Preoperative respiratory support, Speciality b Derivation set AUROC–21 1.00 0.90 0.75 0.50 Sensitivity 0.25 0.10 0.00 0.00 0.10 0.25 0.50 1 – Specificit y AUC = 0.7284 95% CI: 0.714–0.7428 AUC = 0.8036 95% CI: 0.7739–0.8333 0.75 0.90 1.00 0.00 0.10 0.25 0.50 1 – Specificit y 0.75 0.90 1.00 1.00 0.90 0.75 0.50 Sensitivity 0.25 0.10 0.00 Validation set AUROC–21 25: ASA grade, Revised Cardiac Risk Index, Preoperative respiratory support, Speciality 24: Age, Revised Cardiac Risk Index, Preoperative respiratory support, Speciality 22: Age, ASA grade, Revised Cardiac Risk Index, Speciality 23: Age, ASA grade, Preoperative respiratory support, Speciality 14: Age, Revised Cardiac Risk Index, Preoperative repiratory support ASA grade Revised Cardiac Risk Index Variables 23 Mean AUC 0.72 0.71 0.70 0.69 0.68 0.67 0.66 0.65 0.64 0.63 45 Preoperative respiratory support Speciality a Fig. 2 Model performance and evaluation. aLogistic model performance of all different runs divided by each of the features. Colour coded according to performance values (mean area under the curve (AUC) of 100 bootstraps). bReceiver operating characteristic curves for model evaluation. After generating the final model made up by the averaged coefficients of the bootstraps of run 21, it was evaluated in both the derivation set as a whole (Area under receiver operating characteristic curve (AUROC) ¼0.7284, 95 per cent c.i. 0.7140 to 0.7428) and the validation set AUROC ¼0.8036, 95 per cent c.i. 0.7739 to 0.8333). Results are depicted with AUROC and confidence intervals generated through the pROC and plotROC packages. 95 per cent confidence intervals were computed with default 2000 stratified bootstrap replicates. 1276 | BJS, 2021, Vol. 108, No. 11 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 risk of in-hospital SARS-CoV-2 transmission. Research is critical to mitigate impact. The COVIDsurg Morality Score is a tool that can help overcome these challenges and has clear clinical applications. It can inform consent and shared decision making by patients and surgeons. If individual patient mortality risk is too high, they may choose to postpone surgery. If surgery is unavoidable, risks should be clearly documented as part of informed consent, and postoperative critical care can be identified and justified. It can also identify patients who are at very low risk, where surgery can continue as planned. The COVIDSurg Mortality Score shows high discrimination for predicting mortality in patients with perioperative SARS-CoV-2. The AUROCs in the derivation (0.73) and validation (0.80) sets are consistent with published non-surgical COVID risk scores 13 . The COVIDSurg Mortality Score is globally applicable and consists of variables that are readily available across all resource settings. The score was derived and validated in a global data set (all types of surgery, 756 hospitals, 69 countries) and demonstrated validity across geographic regions and over time as community SARS- CoV-2 infection rates fluctuated. The COVIDSurg cohort study was prospectively collected and conducted, but it had limitations. Variables were coded following standardized medical criteria but a further analysis of continuous variablesaswellastheinclusionofinteractions 14 could be incorporated in future studies. As there are no other international, multispecialty data sets for SARS-CoV-2 surgical patients, further external validation was not possible, but should be considered if such data sets emerge. High mortality percentages (approximately 47 per cent) at higher probability outputs (greater than 0.5) should be interpreted with caution, as numbers of patients with these feature combinations were low. The authors acknowledge that the model will warrant updates as more data become available. PROBAST: Prediction model Risk Of Bias ASsessment Tool Step 1: Specify your systematic review question(s) – not applicable. Step 2: Classify the type of prediction model evaluation – development and validation. Step 3: Assess risk of bias and applicability Risk of Bias Participants Predictors Outcome Analysis Were appropriate data sources used, e.g., cohort, RCT, or nested case–control study data? Yes Were predictors defined and assessed in a similar way for all participants? Yes Was the outcome determined appropriately? Yes Were there a reasonable number of participants with the outcome? Yes Were all inclusions and exclusions of participants appropriate? Yes Were predictor assessments made without knowledge of outcome data? Yes Was a prespecified or standard outcome definition used? Yes Were continuous and categorical predictors handled appropriately? Yes Are all predictors available at the time the model is intended to be used? Yes Were predictors excluded from the outcome definition? Yes Were all enrolled participants included in the analysis? No Was the outcome defined and determined in a similar way for all participants? Yes Were participants with missing data handled appropriately? Yes Was the outcome determined without knowledge of predictor information? Yes Was selection of predictors based on univariable analysis avoided? No Was the time interval between predictor assessment and outcome determination appropriate? Yes Were complexities in the data (e.g., censoring, competing risks, sampling of control participants) accounted for appropriately? Yes Were relevant model performance measures evaluated appropriately? Yes Were model overfitting, underfitting, and optimism in model performance accounted for? Yes Do predictors and their assigned weights in the final model correspond to the results from the reported multivariable analysis? Yes ROB ¼risk of bias. þindicates low ROB/low concern regarding applicability; indicates high ROB/high concern regarding applicability; and ? indicates unclear ROB/ unclear concern regarding applicability. Step 4: Overall judgment ROB Applicability Overall Participants Predictors Outcome Analysis Participants Predictors Outcome ROB Applicability þþþþNA NA NA þNA COVIDSurg Collaborative | 1277 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Despite differences in mortality between the derivation and validation sets, model performance remained robust. There are likely to have been structural and system differences between hospitals that were not captured in the cohort study. These differences are further compounded by variation in community SARS-CoV-2 across time and across geographical locations. Nonetheless, the score performed wellinthevalidationset,suggestingthescorecanbeusedreliably both during COVID waves and troughs. Collaborators Writing group: Laura Bravo* (UK), Dmitri Nepogodiev* (UK), James C Glasbey* (UK), Elizabeth Li* (UK), Joana FF Simoes* (Portugal), Sivesh K Kamarajah (UK), Maria Picciochi (Portugal), Tom EF Abbott (UK), Adesoji O Ademuyiwa (Nigeria), Alexis P Arnaud (France), Arnav Agarwal (Canada), Amanpreet Brar (Canada), Muhammed Elhadi (Libya), Dennis Mazingi (Zimbabwe), Victor Roth Cardoso (UK), Samuel Lawday (UK), Raza Sayyed (Pakistan), Omar M Omar (UK), Antonio Ramos de la Madina (Mexico), Luke Slater (UK), Mary Venn (UK), Georgios Gkoutos (UK)†, Aneel Bhangu (UK)† *Joint first authors †Joint Senior Authors Statistical analysis: Laura Bravo, Victor Roth Cardoso, Luke Slater, Andreas Karwath, Georgios Gkoutos. Underlying data have been verified by Dmitri Nepogodiev, Laura Bravo, Aneel Bhangu (overall study guarantor). Operations Committee: Kwabena Siaw-Acheampong, Leah Argus, Daoud Chaudhry, Brett E. Dawson, James C. Glasbey, Rohan R. Gujjuri, Conor S. Jones, Sivesh K. Kamarajah, Chetan Khatri, James M. Keatley, Samuel Lawday, Elizabeth Li, Harvinder Mann, Ella J Marson, Kenneth A. Mclean, Maria Picciochi, Elliott H. Taylor, Abhinav Tiwari, Joana F.F. Simoes, Isobel M. Trout, Mary L. Venn, Richard J.W. Wilkin, Aneel Bhangu*, Dmitri Nepogodiev* *Co-chairs Dissemination Committee: Irida Dajti (Albania), Arben Gjata (Albania), Luis Boccalatte (Argentina), Maria Marta Modolo (Argentina), Daniel Cox (Australia), Peter Pockney (Australia), Philip Townend (Australia), Felix Aigner (Austria), Irmgard Kronberger (Austria), Kamral Hossain (Bangladesh), Gabrielle VanRamshorst (Belgium), Ismail Lawani (Benin), Gustavo Ataide (Brazil), Glauco Baiocchi (Brazil), Igor Buarque (Brazil), Muhammad Gohar (Bulgaria), Mihail Slavchev (Bulgaria), Arnav Agarwal (Canada), Amanpreet Brar (Canada), Janet Martin (Canada), Maria Marta Modolo (Chile), Maricarmen Olivos (Chile), Jose Calvache (Colombia), Carlos Jose Perez Rivera (Colombia), Ana Danic Hadzibegovic (Croatia), Tomislav Kopjar (Croatia), Jakov Mihanovic (Croatia), Jaroslav Klat (Czech Republic), Rene´ Novysedlak (Czech Republic), Peter Christensen (Denmark), Alaa El-Hussuna (Denmark), Sylvia Batista (Dominican Republic), Eddy Lincango (Ecuador), Sameh H Emile (Egypt), Mengistu Gebreyohanes Mengesha (Ethiopia), Samuel Hailu (Ethiopia), Hailu Tamiru (Ethiopia), Joonas Kauppila (Finland), Johanna Laukkarinen (Finland), Alexis Arnaud (France), Markus Albertsmeiers (Germany), Hans Lederhuber (Germany), Markus Loffler (Germany), Stephen Tabiri (Ghana), Symeon Metallidis (Greece), Georgios Tsoulfas (Greece), Maria Aguilera Lorena (Guatemala), Gustavo Grecinos (Guatemala), Tamas Mersich (Hungary), Daniel Wettstein (Hungary), Dhruv Ghosh (India), Gabriele Kembuan (Indonesia), Peiman Brouk (Iran), Mohammad Khosravi (Iran), Masoud Mozafari (Iran), Ahmed Adil (Iraq), Helen M. Mohan (Ireland), Oded Zmora (Israel), Marco Fiore (Italy), Gaetano Gallo (Italy), Francesco Pata (Italy), Gianluca Pellino (Italy), Sohei Satoi (Japan), Faris Ayasra (Jordan), Mohammad Chaar (Jordan), Ildar R Fakhradiyev (Kazakhstan), Mohammad Jamal (Kuwait), Muhammed Elhadi (Libya), Aiste Gulla (Lithuania), April Roslani (Malaysia), Laura Martinez (Mexico), Antonio Ramos De La Medina (Mexico), Oumaima Outani (Morocco), Pascal Jonker (Netherlands), Schelto Kruijff (Netherlands), Milou Noltes (Netherlands), Pieter Steinkamp (Netherlands), Willemijn van der Plas (Netherlands), Adesoji Ademuyiwa (Nigeria), Babatunde Osinaike (Nigeria), Justina Seyiolajide (Nigeria), Emmanuel Williams (Nigeria), Sofija Pejkova (North Macedonia), Knut Magne Augestad (Norway), Kjetil Soreide (Norway), Zainab Al Balushi (Oman), Ahmad Qureshi (Pakistan), Raza Sayyed (Pakistan), Mustafa Abu Mohsen Daraghmeh (Palestine), Sadi Abukhalaf (Palestine), Moises Cukier (Panama), Hugo Gomez (Paraguay), Sebastian Shu (Peru), Ximena Vasquez (Peru), Marie Dione Parreno-Sacdalan (Philippines), Piotr Major (Poland), Jose´ Azevedo (Portugal), Miguel Cunha (Portugal), Irene Santos (Portugal), Ahmad Zarour (Qatar), Eduard- Alexandru Bonci (Romania), Ionut Negoi (Romania), Sergey Efetov (Russia), Andrey Litvin (Russia), Faustin Ntirenganya (Rwanda), Ehab AlAmeer (Saudi Arabia), Dejan Radenkovic (Serbia), Frederick Koh Hong Xiang (Singapore), Chew Min Hoe (Singapore), James Ngu Chi Yong (Singapore), Rachel Moore (South Africa), Ncamsile Nhlabathi (South Africa), Ruth Blanco Colino (Spain), Ana Minaya Bravo (Spain), Ana Minaya-Bravo (Spain), Umesh Jayarajah (Sri Lanka), Dakshitha Wickramasinghe (Sri Lanka), Mohammed Elmujtaba (Sudan), William Jebril (Sweden), Martin Rutega˚rd (Sweden), Malin Sund (Sweden), Arda Isik (Turkey), Sezai Levento glu (Turkey), Tom E.F. Abbott (UK), Ruth Benson (UK), Ed Caruna (UK), Sohini Chakrabortee (UK), Andreas Demetriades (UK), Anant Desai (UK), Thomas D. Drake (UK), John G. Edwards (UK), Jonathan P. Evans (UK), Samuel Ford (UK), Christina Fotopoulou (UK), Ewen Griffiths (UK), Peter Hutchinson (UK), Michael D. Jenkinson (UK), Tabassum Khan (UK), Stephen Knight (UK), Angelos Kolias (UK), Elaine Leung (UK), Siobhan McKay (UK), Lisa Norman (UK), Riinu Ots (UK), Vidya Raghavan (UK), Keith Roberts (UK), Andrew Schache (UK), Richard Shaw (UK), Katie Shaw (UK), Neil Smart (UK), Grant Stewart (UK), Sudha Sundar (UK), Dale Vimalchandran (UK), Naomi Wright (UK), Sattar Alshryda (United Arab Emirates), Osaid Alser (USA), Kerry Breen (USA), Ian Ganly (USA), Haytham Kaafarani (USA), Brittany Kendall (USA), Hassan Mashbari (USA), Hamza Al Naggar (Yemen), Dennis Mazingi (Zimbabwe), EuroSurg, European Society of Coloproctology (ESCP), GlobalSurg, GlobalPaedSurg, ItSURG, PTSurg, SpainSurg, Italian Society of Colorectal Surgery (SICCR), Association of Surgeons in Training (ASiT), Irish Surgical Research Collaborative (ISRC), Joana F.F. Simoes (Chair). Collaborators (*asterix indicates principle investigator):I. Dajti (University Hospital Centre Nene Tereza, Tirana, Albania); J. I. Valenzuela* (Hospital Velez Sarsfield, Buenos Aires, Argentina); L. A. Boccalatte*, N. A. Gemelli, D. E. Smith (Hospital Italiano De Buenos Aires, Buenos Aires, Argentina); N. N. Dudi-Venkata, H. M. Kroon*, T. Sammour (Royal Adelaide Hospital, Adelaide, Australia); M. Roberts*, D. Mitchell*, K. Lah*, A. Pearce, A. Morton (Royal Brisbane and Women’s Hospital, Brisbane, Australia); A. C. Dawson*, A. Drane (Gosford Hospital, Gosford, Australia); C. Sharpin*, R. M. Nataraja*, M. Pacilli (Monash Children’s Hospital, Melbourne, Australia); D. R. A. Cox, V. Muralidharan*, G. E. Riddiough, E. M. Clarke, W. Jamel, K. R. Qin (Austin Hospital, Heidelberg, Australia); P. Pockney*, D. Cope, N. Egoroff, N. Lott (John Hunter Hospital, Newcastle, Australia); S. Putnis, S. De Robles, Z. Ang (Wollongong Public Hospital, Wollongong, 1278 | BJS, 2021, Vol. 108, No. 11 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Australia); M. Mitteregger, S. Uranitsch, M. Stiegler, G. Seitinger, F. Aigner* (Krankenhaus der Barmherzigen Bru¨ der Graz, Graz, Austria); D.B. Lumenta*, S.P. Nischwitz, E. Richtig, M. Pau, P. Srekl-Filzmaier, N. Eibinger, B. Michelitsch, M. Fediuk, A. Papinutti, G. Seidel, J. Kahn, T.U. Cohnert (Medical University of Graz, Graz, Austria); F. Messner, D. O ¨fner* (Medical University of Innsbruck, Innsbruck, Austria); J. Presl*, M. Varga, M. Weitzendorfer, K. Emmanuel (Paracelsus Medical University, Salzburg, Austria); A. D. Binder (Universita¨tsklinikum Tulln, Tulln, Austria); M. Zimmermann, S. Holawe, E. Nkenke, C. Grimm, M. Kranawetter (Medical University of Vienna, Vienna, Austria); A. Rahman Mitul*, N. Islam, S. Karim (Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh); N. Komen*, S. Putnis, S. De Robles, E. Ang (University Hospital Antwerp (UZA), Edegem, Belgium); H. De Praetere*, T. Tollens, G. Schols, C. Smets, L. Haenen (Imelda Hospital, Bonheiden, Belgium); J. Quintens, K Van Belle* (Europe Hospitals, Belgium); G.H. Van Ramshorst*, P. Pattyn, L. Desender, T. Martens, D. Van de Putte (Ghent University Hospital, Ghent, Belgium); P Lerut*, A. Grimonprez, M. Janssen, G. De Smul, P. Wallaert (AZ Groeninge, Kortrijk, Belgium); J. Van den Eynde, W. Oosterlinck*, R. Van den Eynde, A. Sermon, A. Boeckxstaens, A. Cordonnier, J. De Coster, J. Jaekers, C. Politis, M. Miserez (UZ Leuven, Leuven, Belgium); N. Duchateau, C. De Gheldere* (Heilig Hart Ziekenhuis Lier, Lier, Belgium); N. Flamey, P. Pattyn* (AZ Delta, Roeselare, Belgium); A. Christiano*, B. Guidi, A. L. Minussi, S. Castro, W. Okoba, F. H. R. Maldonado, P. Oliveira, T. Baldasso, L. Santos (Fundac¸~ ao Centro Me´dico De Campinas, Campinas, Brazil); G. M. A. Gomes, I. L. Buarque, L. Pol-Fachin, T. S. Bezerra, A. V. Barros*, A. M. R. da Silva, A. L. S. Leite, D. W. A. Silvestre, C. C. Ferro (Hospital Santa Casa De Miserico´rdia De Maceio´ , Maceio´, Brazil); M. S. Araujo*, L. M. Lopes, P. D. Damasceno, D. H. S. Araujo (Hospital Universita´rio Antonio Pedro, Nitero´i, Brazil); G. Laporte*, M. C. Salem (Irmandade Da Santa Casa De Miserico´ rdia De Porto Alegre, Porto Alegre, Brazil); M. A. C. Guimaraes-Filho (Pedro Ernesto University Hospital, Rio de Janeiro, Brazil); L. Nacif* (Hospital Nove De Julho, S~ ao Paulo, Brazil); R. L. G. Flumignan*, L. C. U. Nakano, D. A. B. Kuramoto, A. L. S. Aidar, M. R. Pereda, R. M. Correia, B. C. Santos, A. A. Carvalho, J. E. Amorim, H. J. Guedes Neto, L. L. Areias, A. F. Sousa, C. D. Q. Flumignan, W. G. Lustre, D. H. Moreno, N. Barros Jr, J. C. C. Baptista-Silva (Hospital S~ ao Paulo, S~ ao Paulo, Brazil); L. L. Matos*, L. P. Kowaski, M. A. V. Kulcsar, K. S. Nunes, M. F. Teixeira (Instituto do Caˆ ncer do Estado de S~ ao Paulo, S~ ao Paulo, Brazil); R. L. Nunes*, T. R. Ijichi, N. J. Kim, A. Marreiro, B. Muller, J. Barakat Awada (Notre Dame Interme´dica— Hospital Salvalus, S~ ao Paulo, Brazil); G. Baiocchi*, L. P. Kowalski*, J. G. Vartanian, F. B. Makdissi, S. Aguiar Jr*, N. Marques, G. B. Carvalho, T. M. D. M. Marques, E. A. Abdallah, C. E. Zurstrassen*, J. L. Gross*, S. C. Zequi*, B. T. Gonc¸alves, S. S. Santos, J. P. Duprat, F. J. F. Coimbra* (A.C. Camargo Cancer Center, S~ ao Paulo, Brazil); R. Cicco* (Instituto de Caˆncer Dr Arnaldo Vieira de Carvalho, S~ ao Paulo, Brazil); F. Takeda, I. Cecconello, U. Ribeiro Jr (Instituto Do Caˆncer De Estado De S~ ao Paulo, S~ ao Paulo, Brazil); A. Gatti*, R. Oliva, C. Nardi (Hospital Geral De Pirajussara, S~ ao Paulo, Brazil); M. Slavchev*, B. Atanasov, N. Belev (University Hospital Eurohospital, Plovdiv, Bulgaria); A. Dell, D. Bigam*, K. Dajani, S. Al Riyami (University of Alberta Hospital, Edmonton, Canada); J. Martin*, D. Cheng, H. Yang, A. Fayad (London Health Sciences Centre and St Josephs Health Care London, London, Canada); F.M. Carrier*, E. Amzallag, J. Desroches, M. Ruel (Centre hospitalier de l’Universite´ de Montre´al, Montre´al, Canada); N. G. Caminsky, M. Boutros*, J. Moon, E. G. Wong, T. Vanounou, J. Pelletier, S. Wong, E. Girsowicz, J. Bayne, D. Obrand, H. Gill, O. Steinmetz, K. MacKenzie, M. Lukaszewski, G. Jamjoum (Jewish General Hospital, Montre´al, Canada); P. Richebe´, O. Verdonck, S. Discepola, N. Godin, M. Idrissi (Hoˆpital Maisonneuve-Rosemont, Montre´al, Canada); D. Briatico, S. Sharma, G. Talwar, K. Bailey (McMaster Children’s Hospital, Hamilton, Ontario, Canada); V Lecluyse* (Hoˆpital du Sacre´-Cœur-de-Montre´al, Montre´al, Canada); G. Coˆte´ (Centre hospitalier universitaire Sainte-Justine, Montre´al, Canada); S. Demyttenaere*, R. Garfinkle, M. Boutros* (St. Mary’s Hospital, Kitchener, Canada); A. Kouyoumdjian, M. Boutros*, S. Dumitra, J. Moon, E. G. Wong, K. Khwaja, L. Luo, M. Lukaszewski, H. Gill, G. Berry, A. S. Liberman, E. Girsowicz, J. Bayne, D. Obrand, O. Steinmetz, K. MacKenzie, S. Schmid, J. Spicer, M. Al Farsi* (McGill University Health Center, Montre´al, Canada); J. Abou-Khalil (The Ottawa Hospital, Ottawa, Canada); E. Couture*, S. Mohammadi, H. Tremblay, N. Gagne´, A. Bergeron (Institut universitaire de cardiologie et de pneumologie de Que´bec, Que´bec City, Canada); A. F. Turgeon*, O. Costerousse, D. Bellemare, C. Babin, C. Blier (Centre hospitalier universitaire de Que´bec, Que´bec City, Canada); M. L. Wood, A. Persad, G. Groot*, H. Pham (Saskatoon City Hospital/Royal University Hospital/St. Paul’s Hospital, Saskatoon, Canada); F. D’Aragon*, E. Carbonneau, M. Bouchard, M. Masse, F. Pesant, J. He´roux (Centre hospitalier universitaire de Sherbrooke, Sherbrooke, Canada); P. Karanicolas*, J. Hallet, A. Nadler, A. Nathens (Sunnybrook Hospital, Toronto, Canada); M. Ko*, A. Brar (St. Joseph’s Health Centre, Toronto, Canada); K. Mayson* (Vancouver General Hospital, Vancouver, Canada); B. Kidane*, S. Srinathan (Health Sciences Centre, Winnipeg, Canada); M. I. Escudero*, J. T. Reyes (Hospital Clinico Universidad De Chile/Hospital San Jose, Santiago, Chile); M. M. Modolo*, P. Ramirez Nieto, R. Sepulveda, A. Bolbara´n, A. Molero, I. Ruiz (Barros Luco Trudeau, Santiago, Chile); G. P. Reyes*, R. Salas, C. Suazo (Hospital del Salvador, Santiago, Chile); R. Mu~ noz*, E. Grasset*, M. Inzunza, N. Besser, M. J. Irarra´zaval, C. Jarry, F. Bellolio, C. A. Romero Manqui, M. Ruiz Esquide (Hospital Clı´nico Universidad Cato´lica, Santiago, Chile); T. Fuentes*, J. Campos (Hospital Sotero Del Rio, Puente Alto, Chile); C. J. Perez Rivera*, P. A. Cabrera (Fundacion Cardioinfantil-Instituto de Cardiologı´a, Bogota´, Colombia); R. E. Pinilla*, O. Guevara, L. J. Jimenez Ramirez, B. G. Velasquez Cuasquen, D. R. Herrera Mora, A. Bonilla, S. Diaz*, E. Manrique, H. Facundo, J. L. Velez Bernal, J. A ´ngel, M. Garcı´a, L. Guzma´n, C. Lehmann, S. Cervera, L. M. Trujillo Sanchez (Instituto Nacional De Cancerologia, Bogota´, Colombia); R. Guevara*, D. Valbuena, L. Suarez, G. Jimenez, A. Velandia, J. Vargas, J. Espinosa, S. Rey (Clı´nica Universitaria Colombia, Bogota´ , Colombia); J. Mendoza Quevedo (Subred Sur Occidente de Kennedy (Hospital de Kennedy), Bogota´, Colombia); J. A. Calvache*, C. M. Orozco- Chamorro, T. A. Sa´nchez-Go´ mez, D. A. Rojas-Tejada (Hospital Universitario San Jose´, Popaya´n, Colombia); J. Mihanovic*, B. Bakmaz, I. Rakvin, N. Sulen, T. Andabaka (Zadar General Hospital, Zadar, Croatia); I. Luksic*, M. Mamic (University Hospital Dubrava, Zagreb, Croatia); L. Martinek, M. Skrovina* (Hospital & Oncological Centre Novy Jicin, Novy Jicin, Czech Republic); J.  Zateck y*, M. Peteja (Slezska´ nemocnice v Opav e, p.o., Opav e, Czech Republic); H. Ø. Kristensen, M. Mekhael, P. Christensen*, L. Westh (Aarhus University Hospital, Aarhus, Denmark); H. Smith*, A. F. Haugstvedt, M. L. Jo¨nsson (Bispebjerg Hospital, Copenhagen, Denmark); A. Crespo, S. Batista*, J. Rodriguez-Abreu*, N. Tactuk, P. J. Diaz-Delgado, R. Rivas (Cedimat—Centro De Diagno´stico, Medicina Avanzada, Laboratorio Y Telemedicina, Santo Domingo, Dominican Republic); J. A. Sarmiento-Bobadilla (Hospital General Norte de Guayaquil, Guayaquil, Ecuador); F. Ashoush, A. Samir Abdelaal, COVIDSurg Collaborative | 1279 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 M. S. Qatora, M. E. Elsayed Hewalla, M. Metwalli, R. Atta, A. Abdelmajeed, N. E. Abosamak, A. Sabry*, S. Shehata* (Alexandria Main University Hospital, Alexandria, Egypt); I. Sallam*, G. Amira, M. Sherief, A. Sherif (Misr Cancer Centre, Giza, Egypt); H. Salem*, R. Hamdy, H. Aboulkassem, G. Ghaly*, G. Sherif, A. Morsi, A. Abdelrahman (National Cancer Institute, Cairo, Egypt); A. Omnia (Coptic Hospital, Cairo, Egypt); A. Tawheed, M. El Kassas*, W. Omar (Helwan University, Cairo, Egypt); A. Abdelsamed, A. Seleim, H. Salem*, A. Y. Azzam* (Al Azhar University Hospitals, Cairo, Egypt); M. ElFiky*, A. Nabil (Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt); M. Ibraheem*, G. Ghaly, M. ElDeeb, M. Fawzy (Baheya Centre for Early Detection and Treatment of Breast Cancer, Cairo, Egypt); H. Hamed* (Elkheir Hospital, Mansoura, Egypt); S. Emile*, A. Elfallal, H. Elfeki, M. Shalaby, A. Sakr (Mansoura University Hospital, Mansoura, Egypt); M. Alrahawy*, H. Atif, A. Sakr, H. Soltan (Menoufia University Hospital, Menoufia, Egypt); A. K. Sayed, A. Salah, A. Atiya* (Minia University Hospital, Minia, Egypt); K. Wassim* (Quwaysna Central Hospital, Quwaysna, Egypt); A. M. Abbas, H. A. S. Abd Elazeem, A. Y. Abd-Elkariem, M. M. Abd-Elkarem, S. Alaa, A. K. Ali, M. Ashraf, A. Ayman, M. G. Azizeldine, H. Elkhayat, A. Emad Mashhour, M. Gaber, H. M. Hamza, I. Hawal, H. F. Hetta, S. M. Elghazaly, M. M. Mohammed, F. A. Monib, M. A. Nageh, A. Saad, M. M. Saad, M. Shahine, E. A. Yousof, A. Youssef (Assiut University Hospital, Assiut, Egypt); E. Esmail*, M. Khalaf (Kafr El Zayyat Hospital, Kafr El Zayyat, Egypt); A. Eldaly* (El- Menshawy Hospital, El-Menshawy, Egypt); A. Ghoneim*, A. Hawila, H. Badr, I. Elhalaby, M. Abdel-bari, M. Elbahnasawy, M. K. Hamada, M. S. Morsy, M. Hammad, M. Hammad, M. Essa, M. T. Fayed, M. Elzoghby, M. Rady, O. Hamad, S. Salman, S. Sarsik, S. Abd-elsalam, S. Gamal Badr, Y. El-Masry ( University Hospital, Tanta. Egypt); M. M. H. Moahmmed (Zagazig University Hospitals, Zagazig, Egypt); S. Hailu*, A. Wolde, M. Mengesha, S. Nida, M. Workneh, M. Y. Ahmed, T. Fisseha, D. Kassa, H. Zeleke, A. Admasu, T. Laeke, A. Tirsit, M. Gessesse, A. Addissie (Tikur Anbessa (Black Lion) Hospital-Addis Ababa University, Addis Ababa, Ethiopia); D. Bekele* (Maddawalabu University Goba Referral Hospital, Bale Robe, Ethiopia); J. H. Kauppila*, E. Sarjanoja (La¨ nsi-Pohja Central Hospital, Kemi, Finland); S. Testelin*, S. Dakpe´, B. Devauchelle, J. Bettoni, N. Lavagen (CHU Amiens, Amiens, France); F. Schmitt*, J. M. Leme´e, S. Boucher, R. Breheret, J. D. Ku¨ n-Darbois, A. Kahn, A. Gueutier, P. Bigot (CHU Angers, Angers, France); B. Borraccino (Centre Hospitalier Auxerre, Auxerre, France); Z. Lakkis*, A. Doussot, B. Heyd, S. Manfredelli, P. Mathieu, B. Paquette, C. Turco, A. Barrabe, A. Louvrier (CHU Besanc¸on, Besanc¸on, France); D. Moszkowicz*, D. Giovinazzo, F. Bretagnol (Hoˆ pital Louis-Mourier AP-HP, Paris, France); A. Police*, L. Charre, E. Volpin, H. Braham, N. El Arbi, V. Villefranque, L. Bendjemar (Hoˆpital Simone Veil, Paris, France); E. Girard*, J. Abba, B. Trilling (CHU Grenoble-Alpes, Hoˆpital Michallon, Grenoble, France); A. Chebaro*, K. Lecolle, S. Truant, M. El Amrani, P. Zerbib, F. R. Pruvot, D. Mathieu, E. Surmei, L. Mattei, H. Marin (CHU Lille, Lille, France); N. Christou, Q. Ballouhey*, P. Ferrero, P. Coste Mazeau, J. Tricard, B. Barrat, A. Taibi, J. Usseglio, J. Laloze, H. Salle, L. Fourcade (CHU Limoges, Limoges, France); E. Duchalais*, N. Regenet, J. Rigaud, D. Waast, W. Denis, O. Malard, K. Buffenoir, F. Espitalier, C. Ferron, Y. Varenne, V. Crenn, S. De Vergie, J. Cristini, E. Samarut (Nantes University Hospital, Nantes, France); S. Tzedakis*, P. A. Bouche*, S. Gaujoux (Hoˆ pital Cochin—AP-HP, Paris, France); E. Kantor (APHP Hopital Bichat Claude Bernard, Paris, France); D. Gossot, A. Seguin-Givelet*, D. Fuks, M. Grigoroiu, R. Sanchez Salas, X. Cathelineau, P. Macek, Y. Barbe´, F. Rozet, E. Barret, A. Mombet, N. Cathala, E. Brian, F. Zadegan, C. Conso (Institut Mutualiste Montsouris, Paris, France); T. Blanc*, A. Broch, S. Sarnacki (Necker Enfants Malades University Children Hospital–APHP, Paris; Universite´ de Paris, Paris, France); L. Ali, A. Bonnard, M. Peycelon* (Robert-Debre´ Children University Hospital–APHP, Paris; Universite´ de Paris, Paris, France); E. Hervieux*, P. Clermidi, E. Maisonneuve, E. Aubry, A. Thomin, T. Langlais (Hoˆpital Trousseau–APHP, Paris, France); G. Passot*, O. Glehen, E. Cotte, J. C. Lifante (Hopital Lyon Sud, Pierre Be´nite, France); B. De Simone*, E. Chouillard* (Centre Hospitalier Intercommunal Poissy Saint Germain En Laye, France); A. P. Arnaud*, P. Violas (CHU Rennes–Hoˆpital Sud, Rennes, France); D. Bergeat, A. Merdrignac, A. P. Arnaud (CHU Rennes–Hopital Pontchaillou, Rennes, France); A. Scalabre*, L. O. Perotto, B. Le Roy, E. Haddad, S. Vermersch (CHU Saint Etienne, Saint Etienne, France); A. C. Ezanno*, O. Barbier, F. Vigouroux, B. Malgras, A. Aime (HIA Begin, Paris, France); B. Seeliger*, D. Mutter, G. Philouze, P. Pessaux (IHU- Strasbourg/Strasbourg University Hospitals, Strasbourg, France); A. Germain*, H. Chanty, A. Ayav (CHRU Nancy, Nancy, France); R. Kassir*, P. Von Theobald, F. Sauvat (CHU Reunion, Reunion, France); J. O’Connor*, M. Mayombo Idiata, Z. O’Connor, S. Tchoba (Bongolo Hospital, Lembamba, Gabon); A. Modabber*, P. Winnand, F. Ho¨lzle (University Hospital Aachen, Aachen, Germany); B. Sommer, E. Shiban, S. Wolf, M. Anthuber*, F. Sommer (University Hospital Augsburg, Augsburg, Germany); D. Kaemmerer*, T. Schreiber (Zentralklinik Bad Berka, Bad Berka, Germany); C. Kamphues*, J. C. Lauscher, C. Schineis, F. N. Loch, K. Beyer (Charite´ University Medicine, Campus Benjamin Franklin, Berlin, Germany); S. Nasser, J. Sehouli* (Charite´ Comprehensive Cancer Centre, Berlin, Germany); P. Ho¨hn, C. Braumann*, F. Reinkemeier, W. Uhl (St Josef-Hospital, Bochum, Germany); J. Weitz, U. Bork*, T. Welsch, C. Praetorius, S. Korn, M. Distler (University Hospital Carl Gustav Carus, Technical University Dresden, Dresden, Germany); G. Fluegen, W. T. Knoefel, C. Vay* (University Hospital Du¨ sseldorf, Du¨ sseldorf, Germany); H. Golcher, R. Gru¨ tzmann*, J. Binder (Universita¨tsklinikum Erlangen, Erlangen, Germany); P. Meister*, A. Gallinat, A. Paul (University Hospital Essen, Essen, Germany); A. A. Schnitzbauer*, P. Thoenissen, H. El Youzouri, T. Schreckenbach, T. A. Nguyen (Frankfurt University Hospital, Goethe University, Frankfurt, Germany); H. Eberbach*, J. Bayer*, B. Erdle, R. Sandkamp (Medical Centre—Albert-Ludwigs- University of Freiburg, Freiburg, Germany); C. Nitschke, J. Izbicki, F. G. Uzunoglu*, D. Koenig, M. Gosau, A. Bo¨ ttcher, A. Heuer, T. O. Klatte, M. Priemel, C. S. Betz, S. Burg, N. Mo¨ckelmann, C. J. Busch, J. Bewarder, N. Zeller, R. Smeets, S. Thole, T. Vollkommer, U. Speth, M. Stangenberg (University Medical Center Hamburg- Eppendorf, Hamburg, Germany); I. Hakami*, C. Boeker, J. Mall* (KRH Nordstadt-Siloah Hospitals, Hannover, Germany); H. M. Schardey, T. von Ahnen*, M. von Ahnen, U. Brunner (Agatharied Hospital, Hausham, Germany); C. Tapking*, U. Kneser, C. Hirche, M. Jung, K. F. Kowalewski (BG Trauma Centre Ludwigshafen, Ludwigshafen, Germany); P. Kienle* (Theresienkrankenhaus, Mannheim, Germany); C. Reissfelder, S. Seyfried*, F. Herrle, J. Hardt, C. Galata, E. Birgin, N. Rahbari, N. Vassos (Mannheim University Medical Centre, Mannheim, Germany); M. G. Stoleriu*, R. Hatz (Asklepios Pulmonary Hospital, Munich Gauting, Germany); M. Albertsmeier*, N. Bo¨ rner, C. Lampert, J. Werner (Ludwig-Maximilians-Universita¨t Munich, Munich, Germany); B. Kuehlmann, L. Prantl (University Hospital Regensburg, Regensburg, Germany); S. M. Brunner*, H. J. Schlitt, F. Brennfleck, K. Pfister*, K. Oikonomou (University Medical Centre Regensburg, Regensburg, Germany); T. Reinhard, K. Nowak* (RoMed Klinikum 1280 | BJS, 2021, Vol. 108, No. 11 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Rosenheim, Rosenheim, Germany); U. Ronellenfitsch*, J. Kleeff, K. S. Delank, C. W. Michalski, G. Szabo (University Hospital Halle (Saale), Halle (Saale), Germany); R. Widyaningsih, G. A. Stavrou (Klinikum Saarbru¨ cken, Saarbru¨ cken, Germany); R. Bschorer*, J. Mielke, T. Peschel (Helios Kliniken Schwerin, Schwerin, Germany); A. Ko¨ nigsrainer*, M. Quante, M. W. Lo¨ffler, C. Yurttas (University Hospital Tu¨ bingen, Tu¨ bingen, Germany); J. Doerner*, R. Seiberth (Helios Universita¨tsklinikum Wuppertal, Wuppertal, Germany); K. Bouchagier*, S. Klimopoulos, D. Paspaliari, G. Stylianidis (Evaggelismos General Hospital, Athens, Greece); A. Syllaios, E. Baili, D. Schizas, T. Liakakos, A. Charalabopoulos*, C. Zografos, E. Spartalis (Laiko University Hospital, Athens, Greece); D. K. Manatakis*, N. Tasis, M. I. Antonopoulou (Athens Naval and Veterans Hospital, Athens, Greece); S. Xenaki*, E. Xynos*, E. Chrysos, E. Athanasakis, J. Tsiaousis (University Hospital of Heraklion Crete and Interclinic Hospital of Crete, Heraklion, Greece); E. Lostoridis*, P. Tourountzi (Kavala General Hospital, Kavala, Greece); G. Tzovaras*, K. Tepetes, D. Zacharoulis, I. Baloyiannis, K. Perivoliotis, J. Hajiioannou*, C. Korais, E. Gkrinia, C. E. Skoulakis, A. Saratziotis, O. Koukoura, D. Symeonidis, A. Diamantis (General University Hospital of Larissa, Larissa, Greece); G. Tsoulfas, C. D. Christou, A. Tooulias, V. Papadopoulos*, C. Anthoulakis, G. Grimbizis, D. Zouzoulas, D. Tsolakidis(Papageorgiou General Hospital, Thessaloniki, Greece); D. Tatsis, P. Christidis, L. Loutzidou, O. Ioannidis*, I. Astreidis, A. Antoniou, K. Antoniadis*, K. Vachtsevanos, K. Paraskevopoulos, I. Kalaitsidou, V. Alexoudi, A. Stavroglou, A. Mantevas, D. Michailidou, T. Grivas, D. Deligiannidis, S. Politis (George Papanikolaou General Hospital of Thessaloniki, Thessaloniki, Greece); A. Barrios Duarte*, A. L. Portilla, M. J. Lowey, G. Recinos, I. Lopez Muralles (Hospital General De Enfermedades, Guatemala City, Guatemala); M. A. Siguantay* (Hospital Roosevelt, Guatemala City, Guatemala); E. E. Estrada*, M. L. Aguilera- Are´valo*, J. M. Cojulun, G. Echeverrı´a-Da´vila (Hospital General San Juan De Dios, Guatemala City, Guatemala); C. Marı´n*, G. C. Icaza de Marı´n* (Hospital Regional De Zacapa, Zacapa, Guatemala); S. Y. Kok, H. K. M. Joeng, L. L. Chan, D. Lim (United Christian Hospital, Hong Kong); Z. Novak*, T. Echim (National Institute of Oncology, Budapest, Hungary); N. Suszta´k, B. Banky* (Szent Borba´la Ko´rha´ z, Tataba´nya, Hungary); G. Kembuan, H. Pajan, A. A. Islam* (Rsud Wahidin Sudirohusodo, Jawa Timor, Indonesia); F. Rahim (Baghaei Hospital, Ahvaz, Iran); H. Safari (Golestan Hospital & Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran); M. Mozafari, P. Brouki Milan*, A. Tizmaghz, M. Rezaei Tavirani (Firoozabadi Hospital, Tehran, Iran); A. Ahmed (Baghdad Medical City, Iraq); R. Hussein* (Zafaraniyah General Hospital, Baghdad, Iraq); C. Fleming, S. O’Brien, M. Y. Kayyal, A. Daly, S. Killeen, M. Corrigan* (Cork University Hospital, Cork, Ireland); J. De Marchi, A. Hill*, T. Farrell, N. F. Davis, D. Kearney, T. Nelson (Beaumont Hospital, Dublin, Ireland); P. J. Maguire*, C. Barry*, R. Farrell, L. A. Smith, H. M. Mohan, B. J. Mehigan, P. McCormick, J. O. Larkin*, B. A. Fahey, A. Rogers, N. Donlon, H. O’Sullivan, T. Nugent, J. V. Reynolds*, C. Donohue, P. Shokuhi, N. Ravi, C. Fitzgerald, P. Lennon, C. Timon, J. Kinsella, J. Smith, T. Boyle, D. Alazawi, E. Connolly, W. Butt, S. M. Croghan, R. P. Manecksha (St. James’s Hospital, Dublin, Ireland); N. Fearon*, D. Winter*, H. Heneghan*, D. Maguire, T. Gallagher, K. Conlon, N. Kennedy, S. Martin, R. Kennelly, A. Hanly, K. C. Ng, J. Fagan, E. Geary, C. Cullinane, A. Hanly, E. Carrington, J. Geraghty, E. McDermott, R. Pritchard, D. McPartland, M. Boland, A. Stafford, D. Maguire, J. Geoghegan (St Vincent’s University Hospital, Dublin, Ireland); J. A. Elliott*, P. F. Ridgway, A. E. Gillis, G. A. Bass, P. C. Neary, J. M. O’Riordan, D. O. Kavanagh, I. S. Reynolds, K. Conlon, D. P. Joyce, E. Boyle, B. Egan, M. Whelan, R. Elkady, S. Tierney, T. M. Connelly, H. Earley, M. Umair, C. O’Connell, R. P. Manecksha, A. Z. Thomas, D. Rice, A. Madden, Y. Bashir, B. Creavin (Tallaght Hospital, Dublin, Ireland); O. Cullivan, P. Owens, A. Canas-Martinez, C. Murphy, L. Pickett, B. Murphy, A. Mastrosimone, D. Beddy, M. Arumugasamy, M. Allen, M. Aremu* (Connolly Hospital Blanchardstown, Dublin, Ireland); C. McCarthy, C. O’Connor, D. B. O’Connor*, E. Kent, F. Malone, M. Geary (Rotunda Hospital, Dublin, Ireland); K. L. McKevitt*, A. J. Lowery*, E ´. J. Ryan, T. M. Aherne, A. Fowler, A. Hassanin, A. M. Hogan, C. G. Collins, L. Finnegan, P. A. Carroll, M. J. Kerin, S. R. Walsh (University Hospital Galway, Galway, Ireland); D. Nally*, C. Peirce, J. C. Coffey, R. M. Cunningham, S. Tormey (University Hospital Limerick, Limerick, Ireland); N. P. Hardy*, P. M. Neary (University Hospital Waterford, Waterford/ University College Cork, Cork, Ireland); L. Muallem-Kalmovich, N. Kugler, R. Lavy, O. Zmora* (Shamir Medical Centre, Be’er Ya’akov, Israel); N. Horesh* (Sheba Medical Centre, Ramat Gan, Israel); R. Vergari* (Ospedali Riuniti Di Ancona, Ancona, Italy); S. Mochet*, R. Barmasse, A. Usai, L. Morelli (Ospedale Regionale Umberto Parini, Aosta, Italy); A. Picciariello*, V. Papagni, D. F. Altomare (Azienda Ospedaliero Universitaria Consorziale Policlinico Di Bari, Bari, Italy); M. Colledan*, M. F. Zambelli, S. Tornese, A. Camillo, E. Rausa*, F. Bianco, A. Lucianetti (Asst-Papa Giovanni Xxiii- Bergamo, Bergamo, Italy); G. M. Prucher*, A. M. Baietti, F. Ruggiero, P. Maremonti, F. Neri, S. Ricci, M. Biasini, A. G. Zarabini (Ospedale Maggiore/Bellaria Carlo Alberto Pizzardi Ausl Bologna, Bologna, Italy); A. Belvedere, P. Bernante, P. Bertoglio, S. Boussedra, E. Brunocilla, R. Cipriani, G. Cisternino, E. De Crescenzo, P. De Iaco, A. N. Della Gatta, G. Dondi, F. Frio, E. Jovine, F. Mineo Bianchi, J. Neri, D. Parlanti, A. M. Perrone, A. P. Pezzuto, M. Pignatti, G. Pilu, V. Pinto, G. Poggioli, M. Ravaioli, M. Rottoli*, R. Schiavina, M. Serenari, M. Serra, P. Solli*, M. Taffurelli, M. Tanzanu, M. Tesei, T. Violante, S. Zanotti (Sant’orsola Hospital, Alma Mater Studiorum University of Bologna, Bologna, Italy); V. Tonini*, L. Sartarelli, M. Cervellera, A. Gori (S.Orsola- Malpighi Hospital, Bologna, Italy); G. Armatura*, G. Scotton, S. Patauner, A. Frena (St. Moritz Hospital, Bologna, Italy); M. Podda*, A. Pisanu, G. Esposito, F. Frongia (Cagliari University Hospital, Cagliari, Italy); E. Abate, L. Laface, M. Casati*, M. Schiavo, T. Casiraghi (Ospedale Vittorio Emanuele III—Carate Brianza, Carate Brianza, Italy); G. Sammarco, G. Gallo*, G. Vescio, S. Fulginiti, V. Scorcia, G. Giannaccare, A. Carnevali (University ‘Magna Graecia’ of Catanzaro, Catanzaro, Italy); M. C. Giuffrida*, A. Marano, S. Palagi, S. Di Maria Grimaldi, V. Testa, C. Peluso, F. Borghi, A. Simonato, A. Puppo, M. D’Agruma, R. Chiarpenello, L. Pellegrino, F. Maione, D. Cianflocca, V. Pruiti Ciarello, G. Giraudo, E. Gelarda, E. Dalmasso, A. Abrate, A. Daniele, V. Ciriello, F. Rosato, A. Garnero, L. Leotta (Santa Croce E Carle Hospital, Cuneo, Italy); M. Giacometti*, S. Zonta (San Biagio Hospital, Domodossola—ASL VCO, Domodossola, Italy); D. Lomiento, L. Taglietti, S. Dester, B. Compagnoni, F. Viotti, R. Cazzaniga, R. Del Giudice (ASST Valcamonica Ospedale Di Esine, Esine, Italy); F. Mazzotti*, F. Pasini, G. Ugolini (Ospedale per gli Infermi di Faenza, Faenza, Italy); N. Fabbri, C. V. Feo*, E. Righini, S. Gennari (Azienda Unita` Sanitaria Locale di Ferrara, Ferrara, Italy); M. Chiozza, G. Anania*, A. Urbani, M. Koleva Radica, P. Carcoforo*, M. Portinari, M. Sibilla (Azienda Ospedaliero Universitaria Sant’Anna, Ferrara, Italy); A. Anastasi, B. Bartalucci, A. Bellacci, G. Canonico*, L. Capezzuoli, C. Di Martino, P. Ipponi, C. Linari, M. Montelatici, T. Nelli, G. Spagni, L. Tirloni, A. Vitali (Ospedale San Giovanni Di Dio, Florence, Italy); C. Agostini, G. Alemanno, I. Bartolini, C. Bergamini, A. Bruscino, C. Checcucci, R. De Vincenti, A. Di Bella, COVIDSurg Collaborative | 1281 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 M. Fambrini, L. Fortuna, G. Maltinti, P. Muiesan, F. Petraglia, P. Prosperi*, M. N. Ringressi, M. Risaliti, F. Sorbi*, A. Taddei* (Azienda Ospedaliera Universitaria Careggi, Florence, Italy); V. Lizzi*, F. Vovola, A. Arminio, A. Cotoia, A. L. Sarni (Ospedali Riuniti Azienda Ospedaliera Universitaria Foggia, Foggia, Italy); P. Familiari*, G. D’Andrea, V. Picotti, F. Ba` mbina (Fabrizio Spaziani, Frosinone, Italy); T. Fontana* (Vittorio Emanuele, Italy); F. Barra*, S. Ferrero, C. Gustavino, C. Kratochwila, A. Ferraiolo, S. Costantini, P. Batistotti, A. Aprile, C. Almondo, L. Ball, C. Robba, S. Scabini, D. Pertile, A. Massobrio, D. Soriero (IRCCS Ospedale Policlinico San Martino, Genoa, Italy); S. D’Ugo*, N. Depalma, M. G. Spampinato (‘Vito Fazzi’ Hospital, Lecce, Italy); L. Lippa, C. Gambacciani, O. S. Santonocito*, F. Aquila, F. Pieri (Spedali Riuniti Di Livorno, Livorna, Italy); M. Ballabio*, P. Bisagni, M. Longhi, T. Armao, M. Madonini, A. Gagliano, P. Pizzini (Ospedale Maggiore Di Lodi, Lodi, Italy); A. Costanzi*, M. Confalonieri, M. Monteleone, G. Colletti, C. Frattaruolo, G. Mari (San Leopoldo Mandic, Padua, Italy); A. Spinelli*, G. Mercante, G. Spriano, F. Gaino, F. Ferreli, A. De Virgilio, V. Rossi, M. M. Carvello, F. Di Candido, H. Kurihara, E. Marrano, G. Torzilli, C. Castoro, F. M. Carrano (Humanitas Clinical and Research Centre—IRCCS, Milan, Italy); F. Martinelli, A. Macchi, M. Fiore*, S. Pasquali, S. P. B. Cioffi, M. Baia, C. Abatini, C. Sarre, A. Mosca, D. Biasoni, A. Gronchi, D. Citterio, V. Mazzaferro, P. Cadenelli, M. Gennaro, V. Capizzi, M. Guaglio, L. Sorrentino, G. Bogani, G. Sarpietro, L. Giannini, L. V. Comini, L. Rolli, S. Folli, F. Raspagliesi, C. Piazza, M. Cosimelli, R. Salvioni (Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy); B. Antonelli, L. Baldari, L. Boni, E. Cassinotti*, L. Pignataro, G. Rossi, S. Torretta, G. A. Beltramini, A. Gianni’ (Fondazione IRCSS Ca’ Granda—Ospedale Maggiore Policlinico, Milan, Italy); M. Tagliabue, R. De Berardinis, G. Pietrobon, F. Chu, S. Cenciarelli, L. Adamoli, M. Ansarin*, U. Fumagalli Romario*, F. Mastrilli (Istituto Europeo Di Oncologia—IRCCS, Milano, Italy); N. M. Mariani*, V. Nicastro (Asst Santi Paolo E Carlo, Milan, Italy); P. Cellerino* (Ospedale Fatebenefratelli E Oftalmico, Milan, Italy); F. Colombo*, A. Frontali, A. Bondurri, C. Guerci, A. Maffioli, L. Ferrario (Ospedale Luigi Sacco Milano, Milano, Italy); M. Candiani*, G. Bonavina, J. Ottolina, L. Valsecchi, P. Mortini, F. Gagliardi, M. Piloni, M. Medone, G. Negri, A. Bandiera, P. De Nardi, P. Sileri, M. Carlucci, D. Pelaggi, R. Rosati, A. Vignali, P. Parise, U. Elmore (San Raffaele Scientific Institute, Milan, Italy); N. Tamini*, L. C. Nespoli, M. Rennis, L. Pitoni, M. F. Chiappetta, E. Vico, R. Fruscio, T. Grassi (Ospedale San Gerardo, Universita` degli Studi di Milano Bicocca, Milan, Italy); D. Sasia*, M. Migliore, A. Gattolin, R. Rimonda, E. Travaglio, E. Olearo (Regina Montis Regalis Hospital, Mondovı`, Italy); A. Tufo*, E. Marra, P. Maida, G. Marte, P. Tammaro (Ospedale Del Mare, Naples, Italy); F. Bianco*, P. Incollingo (Ospedale S. Leonardo—Asl Napoli 3 Sud, Castellammare Di Stabia, Naples, Italy); F. Izzo, A. Belli, R. Patrone, V. Albino, M. Leongito, V. Granata, M. Piccirillo, R. Palaia (Istituto Nazionale Tumori Fondazione, G. Pascale-IRCCS, Naples, Italy); E. Francone*, S. Gentilli, H. Nikaj (Azienda Ospedaliero Universitaria Maggiore Della Carita`, Novara, Italy); A. Fiorini, C. Norcini, A. Chessa* (San Giovanni Di Dio, Italy); M. V. Marino*, A. Mirabella, G. Vaccarella (Azienda Ospedaliera, Ospedali Riuniti Villa Sofia-Cervello, Palermo, Italy); L. Musini, L. Ampollini*, M. Bergonzani, A. Varazzani*, L. Bellanti, M. Domenichini, G. Rossi, E. Cabrini, A. Fornasari, A. Freyrie*, D. O. Dejana, G. D’Angelo*, G. Bertoli, F. Di Lella, G. Bocchialini, M. Falcioni, D. Lanfranco, T. Poli (Azienda Ospedaliero-Universitaria di Parma, Parma, Italy); M. Giuffrida, A. Annicchiarico, G. Perrone, F. Catena* (Parma University Hospital, Parma, Italy); A. Raffaele* (Policlinico San Matteo, Pavia, Italy); A. De Manzoni Garberini* (Ospedale Civile Spirito Santo, Pescara, Italy); E. Baldini*, L. Conti, M. Ribolla, P. Capelli, S. M. Isolani, P. Maniscalco, M. Cauteruccio, C. Ciatti, C. Puma Pagliarello, S. Gattoni (Ospedale ‘Guglielmo Da Saliceto’, Piacenza, Italy); R. Galleano*, M. Malerba, M. Ciciliot (Ospedale Santa Corona, Pietra Ligure (SV), Pietra Ligure, Italy); F. Farnesi, M. Calabro`*, N. S. Pipitone Federico, E. G. Lunghi, A. Muratore (Edoardo Agnelli, Italy); L. Morelli*, G. Di Franco, M. Palmeri, D. Tartaglia*, F. Coccolini, M. Chiarugi, T. Simoncini*, A. Gadducci, M. Caretto, A. Giannini, A. Perutelli, L. Domenici*, S. Garibaldi, R. Capanna, L. Andreani, N. Furbetta, S. Guadagni, M. Bianchini, D. Gianardi (Azienda Ospedaliero Universitaria Pisana, Pisa, Italy); E. Pinotti*, M. Montuori, F. Carissimi, G. Baronio (Policlinico San Pietro, Ponte San Pietro, Italy); M. Zizzo*, C. Castro Ruiz, V. Annessi, M. T. Montella, G. Falco*, S. Mele, G. Ferrari, V. Mastrofilippo, V. D. Mandato*, L. Aguzzoli (Azienda Unita` Sanitaria Locale—IRCCS Di Reggio Emilia, Reggio Emilia, Italy); C. Corbellini, C. Baldi*, G. M. Sampietro (Ospedale Di Rho—Asst Rhodense, Rho, Italy); G. M. Palini, N. Zanini*, G. Garulli (Ospedale Infermi di Rimini, Rimini, Italy); R. Barone*, A. Murgese, S. Mungo, M. Grasso, C. Marafante, S. L. Birolo, E. Moggia, M. Caccetta, A. Masciandaro, A. Deirino, M. Garino (Ospedale Degli Infermi Di Rivoli, Rivoli, Italy); R. Perinotti, F. Maiello (Ospedale degli Infermi, Biella, Italy); L. Gordini, C. P. Lombardi, F. Marzi, A. A. Marra, C. Ratto, M. Di Muro, F. Litta, V. De Simone, V. Cozza*, F. Rosa, A. Agnes, A. Parello, S. Alfieri, G. Sganga (Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy); P. Lapolla*, A. Mingoli, G. De Toma, E. Fiori, F. La Torre, P. Sapienza, G. Brachini, B. Cirillo, I. Iannone, M. Zambon, A. Chiappini, S. Meneghini, G. B. Fonsi, P. M. Cicerchia, P. Bruzzaniti, A. Santoro, A. Frati, G. Marruzzo, D. Ribuffo (Policlinico Umberto I Sapienza University of Rome, Rome, Italy); A. Sagnotta*, L. Marino Cosentino, S. Mancini (Ospedale San Filippo Neri, Rome, Italy); G. Lisi*, D. Spoletini (Sant’Eugenio Hospital, Rome, Italy); V. Bellato, M. Campanelli, G. Sica*, L. Siragusa, (Policlinico Tor Vergata Hospital, Rome, Italy); L. Bonavina*, E. Asti, D. Bernardi, A. Lovece (IRCSS Policlinico San Donato, University of Milan, Milan, Italy); T. Perra, A. Porcu*, A. Fancellu, C. F. Feo, A. M. Scanu (Cliniche San Pietro, A.O.U. Sassari, Sassari, Italy); F. Tuminello, R. Galleano*, A. Franceschi, A. Langone (San Paolo, Italy); F. Fleres*, A. Spolini, P. Bordoni, M. Franzini, G. Clarizia, A. Grechi, A. Longhini (Ospedale Di Sondrio (Asst Valtellina E Alto Lario), Sondrio, Italy); E. Guaitoli, G. Manca (Perrino Hospital Brindisi, Italy); U. Grossi, S. Novello, G. Zanus*, M. Romano, S. Rossi (Ca’ Foncello Treviso—DISCOG, Universita` di Padova, Padua, Italy); G. Pirozzolo*, A. Recordare (Dell’Angelo Hospital, ULSS3 Serenissima, Venezia, Italy); S. Paiella, G. Turri, S. Rattizzato, T. Campagnaro*, A. Guglielmi, C. Pedrazzani, A. Ruzzenente, E. Poletto, S. Conci, L. Casetti, M. Fontana, R. Salvia*, G. Malleo, A. Esposito, L. Landoni, M. De Pastena, C. Bassi, M. Tuveri, S. Nobile, G. Marchegiani, L. Bortolasi* (Azienda Ospedaliera Universitaria Integrata Di Verona, Verona, Italy); F. Ferrara (San Carlo Borromeo Hospital, ASST Santi Paolo e Carlo, Italy); M. La Torre (Fabia Mater Hospital, Rome, Italy); E. Sambugaro*, M. Malavolta*, G. Moretto, H. Impellizzeri, M. Inama* (Ospedale Pederzoli, Peschiera del Garda, Italy); G. Barugola, F. Ascari, G. Ruffo (IRCCS Ospedale Sacro Cuore Don Calabria, Negrar di Valpolicella, Verona, Italy); S. Granieri*, C. Cotsoglou (ASST Vimercate, Vimercate, Italy); M. Berselli*, M. Desio, V. Marchionini, E. Cocozza (ASST Settelaghi, Varese, Italy); S. Di Saverio*, G. Ietto, D. Iovino, G. Carcano (University of Insubria, Ospedale di Circolo e Fondazione Macchi, Varese, Italy); F. Ayasra*, A. Qasem, Y. Ayasra (Al-Basheer Hospital, Amman, Jordan); M. Al-Masri*, M. K. Abou Chaar, H. Al-Najjar, K. Ghandour, F. Alawneh, R. Abdel Jalil, 1282 | BJS, 2021, Vol. 108, No. 11 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Shah, S. Saxena, N. Zafar, H. Abdul-Jabar (Northwick Park Hospital, Harrow, UK); M. Patel, A. Shabana, A. Alanbuki*, O. Usman (Princess Royal Hospital, Haywards Heath, UK); C. T. Ong, W. Butterworth*, O. Budha Magar, M. El Hadi, S. Abas, J. Annett (Hereford County Hospital, Hereford, UK); E. Ross, M. Loubani*, A. Wilkins, H. Cao, H. Capitelli-McMahon, L. Hitchman, H. Ikram, A. Andronic, A. Aboelkassem Ibrahim, J. Totty (Hull University Teaching Hospitals NHS Trust, Hull, UK); J. Blanco*, R. Vanker, M. Ghobrial, G. Jones, S. Kanthasamy, H. Fawi, M. Awadallah, F. Chen, J. Cheung* (Hinchingbrooke Hospital, Huntingdon, UK); A. Moscalu*, T. Bhuvanakrishna, L. Bibby, M. Sinclair (Ipswich Hospital, Ipswich, UK); M. A. K. Nahid*, L. Williams, P. S. Basnyat, A. K. Shrestha* (William Harvey Hospital, Ashford, UK); N. K. Kumaran, S. Sambhwani, N. A. Sheikh, O. M. Taylor* (Kettering General Hospital, Kettering, UK); I. Liew*, A. Al-Sukaini, S. Mediratta, D. Saxena (Queen Elizabeth Hospital, King’s Lynn, UK); A. Sgro`, M. M. Rashid, K. Milne, J. McIntyre, M. A. Akhtar*, A. Turnbull, A. Brunt, K. E. Stewart (Victoria Hospital, Kirkcaldy, UK); M. S. J. Wilson*, D. Rutherford, K. McGivern, E. Massie (Forth Valley Royal Hospital, Larbert, UK); M. Ho*, R. G. Wade*, J. Johnstone, G. Bourke, A. Brunelli, H. Elkadi, M. Otify*, C. Pompili, J. R. Burke, E. Bagouri, M. Chowdhury, Z. Abual-Rub, A. Kaufmann, S. Munot, T. Lo*, A. Young, M. Kowal, J. Wall, A. Peckham-Cooper (The Leeds Teaching Hospitals NHS Trust, Leeds, UK); G. R. Layton*, B. Karki, H. Jeong, S. Pankhania, S. Asher, A. Folorunso, S. Mistry, B. Singh, J. Winyard, J. Mangwani (Leicester General Hospital, Leicester, UK); E. J. Caruana*, A. Mohammad, M. Acharya, K. Chandarana, K. Ang, M. F. Chowdhry, S. Rathinam, A. Nakas (Glenfield Hospital, Leicester, UK); A. Boddy*, T. Hossain, C. Ashmore, S. Annamalai, A. Kourdouli, E. Irvine, A. Al-Harbawi, K. Kassam*, A. Al-Harbawee, A. Miller, M. Mair (Leicester Royal Infirmary, Leicester, UK); R. Lunevicius*, A. R. G. Sheel, M. Sundhu, A. J. A. Santini, M. S. A. T. Fathelbab, K. M. A. Hussein, Q. M. Nunes, R. P. Jones, K. Shahzad, I. Haq, M. M. A. S. Baig, J. L. Hughes, A. Kattakayam, K. Rajput, N. Misra, S. B. Shah, A. L. Clynch, N. Georgopoulou, H. M. Sharples, A. A. Apampa, I. C. Nzenwa, A. Sud (Aintree Hospital, Liverpool, UK); A. Harky, B. H. Kirmani*, M. Shackcloth (Liverpool Heart and Chest Hospital, Liverpool, UK); M. D. Jenkinson*, R. Zakaria, T. Elmoslemany, C. P. Millward (The Walton Centre NHS Foundation Trust, Liverpool, UK); R. Baron*, D. Dunne, P. Szatmary, A. Thomas, F. McNicol, S. Gahunia, D. Sochorova, G. E. Nita, R. McKinney, J. Russ, J. R. Tan (Royal Liverpool University Hospital, Liverpool, UK); R. Harwood, H. J. Corbett (Alder Hey In The Park, Liverpool, UK); C. Rossborough, B. L. Skelly (Altnagelvin Area Hospital, Londonderry, UK); N. A. Che Bakri, S. Nazarian, R. Vashisht*, L. Jiao, Z. Jawad (BUPA Cromwell Hospital, London, UK); A. Y. Allan, C. Kontovounisios, T. Grove, O. Warren*, M. G. Fadel (Chelsea and Westminster Hospital, London, UK); M. Chatzikonstantinou, P. Sorelli*, S. Rahman, M. Hadjipavlou (Queen Elizabeth Hospital, Woolwich, UK); C. Holbrook, C. Chong, D. Kufeji (Evelina London Children’s Hospital, London, UK); S. R. Rufai, I. C. Lloyd, G. James*, A. Chari, A. H. D. Silva (Great Ormond Street Hospital for Children, London, UK); L. Stroman, B. Challacombe*, A. Sayasneh*, M. Najdy, A. Bille`, S. Fraser, P. Agoston, V. Rizzo, J. King, R. Nath, S. McCrindle , G. Mehra, K. Harrison-Phipps, J. Pilling, L. Okiror, T. Routledge, L. Mills, A. Wali, K. El-Boghdadly* (Guy’s Hospital, Lopndon, UK); C. Fotopoulou*, S. Saso, M. Fehervari*, J. Ploski, S. Ghaem-Maghami, D. Spalding, P. Rajagopal, M. Pai, N. Habib, Z. Jawad, S. Hamrang- Yousefi, L. Jiao (Hammersmith Hospital, Lndon, UK); S. Tayeh*, T. Chase, L. Humphreys, J. Ayorinde, A. Ghanbari, T. Cuming (Homerton University Hospital, London, UK); N. Anscomb*, R. Baldwin-Smith, M. Rizk, C. Grainger, M. Davies, A. Surendran, J. W. Nunoo-Mensah (King’s College Hospital, London, UK); M. Dunstan*, P. Beak, I. Gerogiannis* (Kingston Hospital NHS Foundation Trust, London, UK); A. Jain, A. Menon, B. Pramodana, D. Choi*, H. J. Marcus, L. Webber, R. May, R. Hutchison, V. Luoma (The National Hospital for Neurology and Neurosurgery, London, UK); S. Ranjit, J. Parakh, V. Sarodaya, A. Daadipour, M. Khalifa (Newham University Hospital, London, UK); K. D. Bosch*, V. Bashkirova, L. S. Dvorkin, V. K. Kalidindi (North Middlesex University Hospital, London, UK); J. Dudek, T. Singhal*, S. El- Hasani (Princess Royal University Hospital, London, UK); A. De Souza, M. Cannoletta, M. Rochon, S. Bhudia (Royal Bromtpon Hospital, London, UK); S. Bennett, L. Navaratne, M. Venn, V. Yip*, B. Kayani, C. Sohrabi, H. M. Kocher, A. Minicozzi, A. Banerjee, T. Sullivan, R. Sivaprakasam*, A. Anzak, K. Ghufoor*, M. A. Thaha*, C. Knowles, F. S. Ledesma, P. Patki*, D. Popova, P. Sadigh*, R. Ramamoorthy, C. Uff*, L. Attwell, C. Tanabalan, M. A. Goh, J. D. Jayasinghe, I. Leal Silva, B. Thakur, M. Lebe, M. S. Thet, F. Hughes*, R. Rahman, O. Fuwa (Royal London Hospital, London, UK); J. Sanders*, A. Oo, T. Bueser, M. Curtis, S. A. Stamenkovic (Cardiac Unit, St Bartholomew’s Hospital, London, UK); T. Abbott*, S. Anwar, C. Sohrabi (St Bartholomew’s Hospital, London, UK); K. Williams*, E. Chung, R. Hagger, A. Karim, A. Hainsworth, M. Flatman, A. Trompeter, C. Hing, O. Brown, P. Tsinaslanidis, M. W. Benjamin, A. Leyte, C. Tan, J. Smelt, P. Vaughan, G. Santhirakumaran, I. Hunt, M. Raza, A. Labib (St George’s Hospital, London, UK); X. Luo, A. Sudarsanam, A. Rolls, O. Lyons, S. Onida, J. Shalhoub, K. Sugand, C. Park, K. M. Sarraf*, S. Erridge, J. Kinross*, M. Denning, S. Yalamanchili, A. Abuown, M. Ibrahim, G. Martin (St Mary’s Hospital, London, UK); D. Davenport, S. Wheatstone* (St Thomas’ Hospital, London, UK); V. Kasivisvanathan*, K. Kapriniotis, A. Elhamshary, S. M. B. Imam (University College London Hospital At Westmoreland Street, London, UK); N. Kalavrezos*, D. Sinha, M. Chand, L. Green, N. Beech, R. McEwen, H. Kiconco (University College London Hospital, London, UK); S. M. Andreani*, M. F. Bath, A. Sahni, N. Judkins, L. Rigueros Springford, C. Sohrabi, J. Bacarese- Hamilton, F. G. Taylor, P. Patki*, C. Tanabalan (Whipps Cross University Hospital, London, UK); C. Parmar*, S. McCluney, S. Shah (The Whittington Hospital, London, UK); R. Talwar*, K. Patel, A. Askari, P. S. Jambulingam, S. Shaw, A. Maity, C. Hatzantonis, J. Sagar, S. Kudchadkar, N. Cirocchi, C. H. Chan (Luton and Dunstable University Hospital, Luton, UK); J. Reynolds, M. E. Alexander, C. J. Smart* (Macclesfield District General Hospital, Macclesfield, UK); B. Jayasankar, D. Balasubramaniam*, K. Abdelsaid, N. Mundkur, B. Gallagher* (Tunbridge Wells Hospital, Tunbridge Wells, UK); J. Shah*, J. Anthoney, O. Emmerson (North Manchester General Hospital, Manchester, UK); N. Stylianides*, M. Abdalla, K. Newton, K. Bhatia*, R. Edmondson, L. Abdeh, D. Jones, M. Zeiton, O. Ismail, H. Naseem, R. Advani (Manchester Royal Infirmary, Manchester, UK); S. Duff*, F. Moura, B.C. Brown, A. Khan, P. Asaad, B. Wadham, I. A. Aneke, J. Collis, H. Warburton (Wythenshawe Hospital, Manchester, UK); A. Fell*, A. Smith, C. Halkias, J. Evans, S. Nikolaou, C. English*, S. Kristinsson, T. Oni, N. Ilahi, K. Ballantyne, Z. Woodward, R. Merh (Queen Elizabeth The Queen Mother Hospital, Margate, UK); J. Dunning, Y. Viswanath, K. Freystaetter, J. Dixon*, J. N. Hadfield, A. Hilley, A. Egglestone, B. Smith (James Cook University Hospital, Middlesborough, UK); T. Hine, B. Keeler*, R. E. Soulsby, A. Taylor* (Milton Keynes University Hospital, Milton Keynes, UK); E. Davies*, O. Ryska, T. Raymond, S. Rogers*, A. Tong, P. Hawkin (Royal Lancaster Infirmary, Lancaster UK); S. Tingle, F. Abbadessa, A. Sachdeva, B. COVIDSurg Collaborative | 1289 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Rai*, C. D. Chan, I. McPherson, K. Booth, F. Mahmoud Ali, S. Pandanaboyana, T. Grainger, S. Nandhra, A. Patience, A. Rogers*, C. Roy, T. Williams, N. Dawe, C. McCaffer, J. Riches, S. Bhattacharya, J. Moir, N. S. Kalson, H. Elamin Ahmed, C. Mellor, C. Saleh, R. M. Koshy, J. Hammond*, L. Sanderson, S. Wahed, A. W. Phillips, K. Ghosh* (Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne UK); A. Tang, A. J. Beamish, C. Price, D. Bosanquet*, D. Magowan, F. Solari, G. Williams, H. Nassa, L. Smith (Royal Gwent Hospital, Newport, UK); B. Robertson-Smith, A. Mahmoud, P. Ameerally, J. G. Finch*, C. Gnanachandran, I. Pop, M. Rogers, Y. Yousef, I. Mohamed, R. Woods, H. Zahid, G. Mundy* (Northampton General Hospital, Northampton, UK); M. Youssef*, L. Sreedharan, D. Baskaran, I. Shaikh, K. Seebah, J. Reid, D. Watts, V. Kouritas, D. Chrastek, G. Maryan, D. F. Gill, F. Khatun (Norfolk and Norwich University Hospital, Norwich, UK); K. Gajjar, K. Williamson, D. Bratt, K. Konstantinidi, T. Walton*, N. Burnside*, H. Weaver, M. Hawari, E. Addae-Boateng, R. A. Rollett*, M. L. Collins, M. S. Tamimy, H. Riyat, J. Wen, J. Neil-Dwyer (Nottingham City Hospital, Nottingham, UK); H. Brewer, D. Humes*, D. Worku, A. Chowdhury*, O. Oyende, C. Lewis-Lloyd, A. Adiamah, A. Koh, J. Jackman, R. Vohra*, A. Navarro*, J. Reilly (Queens Medical Centre, Nottingham, UK); A. Aujayeb, D. Townshend*, N. McLarty, A. Shenfine, K. Jackson, C. Johnson (Northumbria NHS Hospital Trust, UK); D. Dass, D. Ford (Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, UK); S. C. Winter*, E. Belcher*, D. Stavroulias, F. Di Chiara, K. Wallwork, A. Qureishi, M. Lami, S. Sravanam, S. Mastoridis, K. Shah, S. Chidambaram, R. Smillie, A. V. Shaw, S. Bandyopadhyay, C. Cernei, C. Bretherton, D. Jeyaretna*, M. Ganau*, R. J. Piper*, E. Duck, S. Brown, C. Jelley, S. C. Tucker*, G. Bond-Smith*, X. L. Griffin*, G. D. Tebala, N. Neal*, M. Vatish*, T. M. Noton, H. Ghattaura, M. Maher, H. Fu, O. B. F. Risk, H. Soleymani Majd, S. Sinha*, S. Shankar, A. Aggarwal, H. Kharkar, K. Lakhoo*, C. Verberne, S. Mastoridis (Oxford University NHS Foundation Trust, Oxford, UK); B. Dean*, C. Luney, R. Myatt, M. A. Williams, J. McVeigh (Nuffield Orthopaedic Centre, Oxford, UK); L. J. Rogers*, P. L. Labib, D. Miller, G. Minto, N. Hope, A. Marchbank, K. Emslie, P. Panahi, B. Ho, C. Perkins, E. Clough, H. Roy, I. Enemosah, R. Campbell, J. Natale, K. Gohil, M. Rela, N. Raza, (Derriford Hospital, Plymouth, UK); I. Biliatis* (Poole Hospital, Poole, UK); J. Khan*, G. Thiruchandran, S. K. C. Toh*, Y. Ahmad*, A. Allana, C. Bellis, O. Babawale, Y. C. Phan, U. Lokman, M. Ismail, T. Koc, A. Witek, L. Duggleby, S. Shamoon, S. Stefan, H. Clancy (Queen Alexandra Hospital, Portsmouth, UK); R. Chadha*, S. B. Middleton, K. Wilmott, C. Hayden, C. Mclaren, J. Sutton, A. Whyte (Royal Berkshire Hospital, Reading, UK); A. Belgaumkar*, A. Day, C. Gilbert, B. Oyewole, P. Narayan, H. Dent, A. Sandhya, T. De Silva, S. Waheed (Surrey and Sussex Healthcare NHS Trust, Sussex, UK); A. Day, K. Kapoor, A. P. Belgaumkar*, P. Narayan, M. Fahim (East Surrey Hospital, Redhill, UK); T. Gala, R. Mithany, R. Morgan*, M. Abdelkarim, S. Ibrahim, A. Maw*, A. Asqalan, G. Sundaram Venkatesan (Glan Clwyd Hospital, Rhyl, UK); S. Singh, S. Mukherjee*, D. Ferguson, C. Smith, A. Mansuri, A. Thakrar, L. Wickramarachchi, R. Cuthbert, S. Sivayoganathan, K. Chui, E. Karam, C. Dott, S. Shankar (Queen’s Hospital, Romford, UK); K. Madhvani, M. Hampton, A. P. Hormis* (Rotherham District General Hospital, Rotherham, UK); M. Thomas, L. Pearce*, D. M. Fountain, R. Laurente, K. V. Sigamoney, M. Dasa, K. George*, Z. Naqui*, M. Galhoum, C. Lipede, A. Gabr, A. Radhakrishnan, M. T. Hasan, R. Kalenderov, O. Pathmanaban, F. Colombo, R. Chelva (Salford Royal NHS Foundation Trust, Salford, UK); G. Branagan*, L. Longstaff, D. Ding, C. Barlow, J. Foster (Salisbury NHS Foundation Trust, Salisbury, UK); J. Edwards*, A. Ward, D. Tadross, L. Majkowski, C. Blundell, S. Forlani, R. Nair, S. Guha, S. R. Brown, C. Steele, C. J. Kelty*, T. Newman, M. Lee, G. Chetty*, G. Lye, S. P. Balasubramanian, N. Sureshkumar Shah, M. Sherif, A. Al-mukhtar, E. Whitehall, A. Giblin, F. Wells, A. Sharkey, A. Adamec, S. Madan (Sheffield Teaching Hospital NHS Foundation Trust, Sheffield, UK); B. Narice, M. Sterrenburg, A. Thompson, I. Varley, M. Stavrakas, O. Rominiyi, J. Ray, A. Adamec, M. Crank, A. Bacon, Y. Al-Tamimi, J. Catto, S. Saad, N. N. Abd Kahar, S. Sinha (Royal Hallamshire Hospital, Sheffield, UK); A. Sou, D. Simpson, E. Hamilton*, J. Blair (Shrewsbury and Telford Hospitals, Shrewsbury, UK); S. Jallad, J. Lord, C. Anderson, J. El Kafsi*, K. Logishetty*, A. Saadya, R. Midha, M. Ip, H. Subbiah Ponniah, T. Stockdale, T. Bacarese-Hamilton, L. Foster, A. James, N. Anjarwalla, D. Marujo Henriques, R. Hettige, C. Baban, A. Tenovici, G. Salerno (Wexham Park, Frimley Health NHS FT, UK); R. Singh*, J. Lane, H. V. Colvin, A. Badran*, A. Cadersa, S. Williams, A. Cumpstey, Z. Hamady, R. Aftab, F. Wensley, J. Byrne, V. Morrison-Jones, G. K. Sekhon, H. Shields, Z. Shakoor, A. Yener, T. Talbot, A. Khan, A. Alzetani*, R. Cresner (Southampton General Hospital, Southampton, UK); B. H. B. Babu*, A. S. D. Liyanage, S. Newman, I. Blake, C. Weerasinghe (Southport and Formby District General Hospital, Southport, UK); R. Baumber, J. Parry* (Royal National Orthopaedic Hospital, Stanmore, UK); C. Menakaya*, J. I. Webb, M. Antar, N. Modi, R. Sofat, J. Noel, R. Nunn, S. Adegbola, F. Eriberto, V. Sharma, R. Tanna, S. Lodhia (East and North Hertfordshire NHS Trust, Lister Hospital, Stevenage, UK); D. Johnson*, I. Hughes, J. Hall, J. Rooney, S. Chatterji, Y. Zhang, R. Owen, M. Rudic, J. Hunt (Stepping Hill Hospital, Stockport, UK); D. Zakai, M. Thomas*, A. Aladeojebi, M. Ali, A. Gaunt*, B. Barmayehvar, M. Kitchen, M. Gowda, F. Mansour, M. Jarvis, E. Halliday, R. Lefroy, P. Nanjaiah, S. Ali, M. Kitchen* (Royal Stoke University Hospital, Stoke, UK); D. J. Lin, A. D. Rajgor, R. J. Scurrah, C. Kang, L. J. Watson, G. Harris, T. Royle*, Y. Cunningham, G. James, B. Steel, A. C. O. Luk (Sunderland Royal Hospital, Sunderland, UK); A. J. Boulton, M. T. Khan, G. Bakolas, I. Ahmed* (Good Hope Hospital, Sutton Coldfield, UK); P. Herrod, E. Gemmill*, H. Boyd-Carson, M Jibreel, E. Lenzi, T. Saafan, D. Sapre (King’s Mill Hospital, Sutton-in-Ashfield, UK); Z. Li*, K. Parkins, N. Spencer, R. Harries, R. J. Egan, D. Motter, C. Jenvey, R. Mahoney, N. Fine, T. Minto, A. Henry (Morriston Hospital, Swansea, UK); M. Hollyman*, C. Grieco, C. Gemmell (Musgrove Park Hospital, Taunton, UK); H. Whitmore, M. S. Babar, S. Goodrum, R. Scott, B. Collard, K. Lau, E. Thomas, A. Patel, J. Allison, J. Bowen (Torbay and South Devon NHS Trust, Torquay, UK); A. Dias, B. Mahendran, S. Gopalswamy* (Royal Cornwall Hospital, Truro, UK); S. Patil, L. Scott, J. Sarveswaran*, M. Michel, S. Ravindran (Pinderfields Hospital, Wakefield, UK); K. Subba, A. K. Abou-Foul, M. Khalefa, F. Hossain*, T. Moores, L. Pickering (Walsall Manor Hospital NHS Trust, Walsall, UK); G. Stables*, A. Doorgakant*, V. G. Thiruvasagam, J. Carter, S. Reid, R. Mohammed, W. Marlow (Warrington & Halton Teaching Hospitals NHS Trust, Warrington, UK); H. Ferguson*, R. Wilkin, C. Konstantinou, D. Yershov, J. Vatish, A. Denning (South Warwickshire NHS Foundation Trust, UK); H. B. Shah, G. W. V. Cross, P. Seyed-Safi*, Y. W. Smart, A. Kuc, M. Al-Yaseen (Watford General Hospital, Watford, UK); J. Olivier*, M. Hanna, P. Eskander, R. Duncan, S. Halaseh (Weston General Hospital, Weston-super-Mare, UK); R. Das* (Hampshire Hospitals NHS Trust, Basingstoke, UK); H. Wynn Jones, H. Divecha*, C. Whelton, T. Board (Wrightington, Wigan & Leigh NHS Foundation Trust, Wigan, UK); S. Powell*, C. Magee*, K. Agarwal*, E. Mangos, T. Nambirajan (Wirral University Teaching Hospital, Birkenhead, UK); R. Vidya*, G. Chauhan, J. Kaur, A. Burahee, S. Bleibleh, N. Pigadas*, D. Snee, S. Bhasin*, A. Crichton, 1290 | BJS, 2021, Vol. 108, No. 11 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 A. Habeebullah, A. S. Bodla, N. Yassin*, M. Mondragon, V. Dewan (Royal Wolverhampton NHS Trust, Wolverhampton, UK); I. Flindall, V. Mahendran, A. Hanson (Worcestershire Royal Hospital, Worcester, UK); E. Jenner, J. Richards, K. Thomas- Fernandez, R. Wall (Worcestershire Acute Hospitals NHS Trust, Worcester, UK); A. Alqallaf, A. Ben-Sassi*, I. Mohamed, K. Mellor, P. Joshi, Y. Joshi (Wrexham Maelor Hospital, Wrexham, UK); R. Young*, V. Miu, K. Sheridan, L. MacDonald, S. Green, L. Onos (York Teaching Hospitals NHS Trust, York, UK); J. J. Wong, L. Napolitano*, M. Hemmila (Michigan Medicine, Ann Arbor, USA); D. Amin*, S. Abramowicz, S. M. Roser (Emory University, Atlanta, USA); K. A. Olson, C. Riley, C. Heron, T. Cardenas*, E. Leede, M. Thornhill, A. B. Haynes*, K. McElhinney, S. Roward, M. D. Trust*, C. E. Hill, P. G. Teixeira* (Dell Seton Medical Center at the University of Texas at Austin, Austin, USA); E. Etchill, K. Stevens*, M. R. Ladd, C. Long, J. Rose, A. Kent, P. Yesantharao, D. Vervoort, H. Jenny, A. Gabre-Kidan, A. Margalit, L. Tsai, H. Malapati, L. Yesantharao (Johns Hopkins Hospital, Baltimore, USA); H. Abdou, J. Diaz*, M. Richmond, J. Clark, L. O’Meara, N. Hanna (University of Maryland Medical Center, Baltimore, USA); Y. Ying*, J. Fleming, A. Ovaitt, J. Gigliotti, A. Fuson (University of Alabama, Birmingham, USA); Z. Cooper*, A. Salim*, S. A. Hirji, A. Brown, C. Chung, L. Hansen, B. U. Okafor, V. Roxo, C. P. Raut, J. S. Jolissaint, D. A. Mahvi (Brigham and Women’s Hospital, Boston, USA); H. Kaafarani*, K. Breen, B. Bankhead-Kendall, O. Alser, H. Mashbari, G. Velmahos, L. R. Maurer, M. El Moheb, A. Gaitanidis, L. Naar, M. A. Christensen, C. Kapoen, K. Langeveld, M. El Hechi, A. Mokhtari (Massachusetts General Hospital, Boston, USA); M. H. Haqqani, F. T. Drake* (Boston Medical Center, Boston, USA); A. Goldenberg- Sandau*, B. Galbreath (Cooper University Hospital, Camden, USA); C. Reinke*, S. Ross, K. Thompson, D. Manning, R. Perkins (Atrium Health Carolinas Medical Center, Charlotte, USA); E. Eriksson*, H. Evans (Medical University of South Carolina, Charleston, USA); M. Masrur, P. Giulianotti, E. Benedetti (University of Illinois at Chicago, Chicago, USA); G. Chang*, J. Ourieff, D. Dehart (Mount Sinai Hospital, USA); A. Dorafshar, T. Price, A. R. Bhama, A. Torquati*, E. Cherullo, R. Kennedy, J. Myers (Rush University Medical Center, Chicago, USA); K. Rubin* (University Hospitals of Cleveland, Cleveland, USA); V. S. Ban*, S. G. Aoun, H. H. Batjer, J. Caruso (University of Texas Southwestern, Dallas, USA); H. Carmichael, C. G. Velopulos*, F. L. Wright, S. Urban, R. C. McIntyre Jr, T. J. Schroeppel*, E. A. Hennessy, J. Dunn*, L. Zier (University of Colorado Hospital/ Memorial Hospital/Medical Center of the Rockies, Loveland, USA); C. Burlew*, J. Coleman* (Denver Health, Denver, USA); K. P. Colling* (Saint Mary’s Medical Center-Essentia Health, Duluth, USA); B. Hall, H. E. Rice*, E. S. Hwang, S. A. Olson, D. Moris (Duke University Medical Center, Durham, USA); R. Verma*, R. Hassan (Nassau University Medical Center, Nassau, USA); A. Volpe, S. Merola (NewYork Presbyterian Queens, Flushing, USA); L. A. O’Banion*, J. Lilienstein, R. Dirks (University of California San Francisco-Fresno, Fresno, USA); H. Marwan*, M. Almasri*, G. Kulkarni, M. Mehdi, A. Abouassi, M. Abdallah, M. San Andre´s, J. Eid, E. Aigbivbalu, J. Sundaresan, B. George (University of Texas Medical Branch, Galveston, USA); A. Ssentongo, P. Ssentongo, J. S. Oh, J. Hazelton*, J. Maines, N. Gusani, M. Garner, S. Horvath (Pennsylvania State University, State College, USA); F. Zheng* (Houston Methodist Hospital, Houston, USA); M. Ujiki (Northshore University Healthsystem, Chicago, USA); G. Kinnaman, A. Meagher*, I. Sharma, E. Holler (Iu Health Methodist Hospital, Indianapolis, USA); K. McKenzie*, J. Chan, K. Fretwell, W. Nugent III, A. Khalil, D. Chen, N. Post, T. Rostkowski, D. Brahmbhatt (Jamaica Hospital, Richmond Hill, USA); K. Huynh, M. L. Hibbard (Kaiser Permanente West Los Angeles, Los Angeles, USA); M. Schellenberg* (LACþUSC Medical Center, Los Angeles, USA); R. C. G. Martin*, N. Bhutiani (University of Louisville Hospital and Norton Hospital, Louisville, USA); E. Giorgakis*, J. Laryea, A. Bhavaraju, K. Sexton, M. Roberts, M. Kost, M. Kimbrough, L. Burdine, K. Kalkwarf, R. Robertson (University of Arkansas for Medical Sciences, Little Rock, USA); A. Gosain*, L. Camp, R. Lewit (Le Bonheur Children’s Hospital, Memphis, USA); J. P. Kronenfeld, E. Urrechaga, N. Goel, R. Rattan, V. Hart*, M. Allen, G. Gilna (Jackson Memorial Hospital, Miami, USA); A. Cioci, G. Ruiz*, M. Allen, K. Rakoczy, W. Pavlis, R. Saberi (University of Miami Hospital, Miami, USA); R. Morris*, B. S. Karam (Froedtert Hospital, Milwaukee, USA); C. E. M. Brathwaite*, H. Liu, P. Petrone, H. Hakmi, A. H. Sohail, G. Baltazar, R. Heckburn (NYU Langone Health-NYU Winthrop Hospital, Mineola, USA); R. M. Nygaard*, E. T. Colonna, F. W. Endorf, M. J. Hill (Hennepin Healthcare, Minneapolis, USA); A. Maiga, B. Dennis*, J. H. Levin, M. Lallemand (Vanderbilt University Medical Center, Nashville, USA); R. Choron, G. Peck*, F. Soliman, S. Rehman (Robert Wood Johnson University Hospital, New Brunswick, USA); N. Glass*, B. Juthani, D. Deisher (The University Hospital, Newark, USA); N. M. Ruzgar, S. J. Ullrich*, M. Sion* (Yale New Haven Hospital, New Haven, USA); C. Paranjape*, M. El Moheb, A. R. Kar (Newton Wellesley Hospital, Newton, USA); C. Gillezeau, J. Rapp, E. Taioli, B. A. Miles*, N. Alpert (Mount Sinai Hospital, USA); D. Podolsky*, N. L. Coleman, M. P. Callahan (NewYork-Presbyterian/Columbia University Medical Center, New York, USA); I. Ganly*, L. Brown (Memorial Sloan Kettering Cancer Center, New York, USA); J. R. T. Monson (AdventHealth Orlando, Orlando, USA); A. Dehal* (Kaiser Permanente Panorama City Medical Center, Panorama City, USA); A. Abbas, A. Soliman, B. Kim, C. Jones, E. Dauer, E. Renza- Stingone, E. Hernandez, E. Gokcen, E. Kropf, H. Sufrin, H. Hirsch, H. Ross, J. Engel, J. Sewards, J. Diaz, J. Poggio, K. Sanserino, L. Rae, M. Philp*, M. Metro, P. McNelis, R. Petrov, S. Rehman, T. Pazionis (Temple University Hospital, Philadelphia, USA); B. Till, R. Lamm, A. J. Rios-Diaz, F. Palazzo* (Thomas Jefferson University Hospital, Philadelphia, USA); M. Rosengart*, K. Nicholson (University of Pittsburgh Medical Center, Pittsburgh, USA); M. M. Carrick*, K. Rodkey (Medical City Plano, Plano, USA); A. Suri, R. Callcut* (UC Davis Medical Center, Sacramento, USA); S. Nicholson*, N. Talathoti (UT Health San Antonio (UTHSA), University Hospital (UHS), San Antonio, USA); D. Klaristenfeld* (Kaiser Permanente San Diego Medical Center, USA); Biffl W*, Marsh C, Schaffer K (Scripps Memorial Hospital, San Diego, USA); A. E. Berndtson*, S. Averbach, T. Curry (University of California, San Diego, USA); R. Kwan-Feinberg*, E. Consorti, R. Gonzalez, R. Grolman, T. Liu, O. Merzlikin (Alta Bates Summit Medical Center (Sutter Health), Oakland, USA); M. K. Abel, D. Ozgediz, M. Boeck, L. Z. Kornblith*, B. Nunez-Garcia, B. Robinson, P. Park (University of California San Francisco (UCSF), San Francisco, USA); A. F. Utria, S. E. Rice- Townsend*, P. Javid, J. Hauptman, K. Kieran (Seattle Children’s Hospital, Seattle, USA); D. Nehra*, A. Walters, J. Cuschieri, G. H. Davidson (Harborview Medical Center, Seattle, USA); J. Nunez*, R. Cosker (University of Utah Healthcare, Salt Lake City, USA); S. Eckhouse* (Washington University School of Medicine, St Louis, USA); A. Choudhry, W. Marx* (SUNY Upstate University Hospital, Syracuse, USA); T. Jamil*, S. Seegert, S. Al-Embideen (ProMedica Toledo Hospital, Toledo, USA); M. Quintana*, H. Jackson (The George Washington University Hospital, Washington, D.C., USA); S. D. Wexner, I. Kent (Cleveland Clinic Florida, Weston, USA); P. N. Martins* (University of Massachusetts, UMass Memorial Hospital, Worcester,USA);M.Alshehari*,H.Al-Naggar*,M.Alsayadi, M.Alyazidi,S.Shream,W.Alhaddad,A.Maqus,M.AbuHamra’a,R. COVIDSurg Collaborative | 1291 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 Alsayadi,R.Ghannam,S.Al-Maqtari,S.Masdoos,Y.Al-Harazi,H. Bajjah (Al-Thawra Modern General Hospital, Sana’a, Yemen); S. Al- Ameri, M. Aldawbali (Royal Hospital, Sana’a, Yemen); G. P. Gwini* (Mpilo Central Hospital, Bulawayo, Zimbabwe); D. Mazingi* (Parirenyatwa hospital, Harare, Zimbabwe). Funding This report was funded by a National Institute for Health Research (NIHR) Global Health Research Unit Grant (NIHR 16.136.79), Association of Coloproctology of Great Britain and Ireland, Bowel & Cancer Research, Bowel Research UK, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology,Medtronic,NIHRAcademy,TheUrology Foundation, Sarcoma UK, Vascular Society for Great Britain and Ireland, Yorkshire Cancer Research, and the MRC Health Data Research UK (HDRUK/CFC/01), an initiative funded by UK Research and Innovation, Department of Health and Social Care (England) and the devolved administrations, and leading medical research charities. L.B.M. and G.V.G. also acknowledge the Wellcome Trust 4- year studentship programme in mechanisms of inflammatory disease (MIDAS; 215182/Z/19/Z). The funders had no role in study design, data collection, analysis and interpretation, or writing of this report. The views expressed are those of the authors and not necessarily those of the National Health Service, the NIHR, or the UK Department of Health and Social Care. Acknowledgements Xiao Liu, Alistair Denniston, Royal College of Surgeons of England COVID-19 Research Group. Data sharing requests will be considered by the management group upon written request to the corresponding author. Disclosure: The authors declare no conflict of interest. Supplementary material Supplementary material is available at BJS online. References 1. Covidsurg Collaborative. Elective surgery cancellations due to the COVID-19 pandemic: global predictive modelling to inform surgical recovery plans. Br J Surg 2020;107:1440–1449. 2. Covidsurg Collaborative. Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study. 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The Lancet 2021;397:373. 13. KnightSR,HoA,PiusR,BuchanI,CarsonG,DrakeTMet al. Risk stratification of patients admitted to hospital with covid- 19 using the ISARIC WHO Clinical Characterisation Protocol: development and validation of the 4C Mortality Score. BMJ 2020;371:m4334. 14. Clift AK, Coupland CAC, Keogh RH, Diaz-Ordaz K, Williamson E, Harrison EM et al. Living risk prediction algorithm (QCOVID) for risk of hospital admission and mortality from coronavirus 19 in adults: national derivation and validation cohort study. BMJ 2020;371:m3731. 1292 | BJS, 2021, Vol. 108, No. 11 Downloaded from https://academic.oup.com/bjs/article/108/11/1274/6316029 by Universidad de Sevilla user on 11 October 2022 European Colorectal Congress 28 November – 1 December 2022, St.Gallen, Switzerland E U R O P E A N C O L O R E C T A L C O N G R E S S 2022 2 8 N o v – 1 D e c · S t . G a l l e n · S w i t z e r l a n d Information & Registration www.colorectalsurgery.eu Tuesday, 29 November 2022 9.00 CONSULTANT‘S CORNER Michel Adamina, Winterthur, CH 10.30 COFFEE BREAK 11.00 SATELLITE SYMPOSIUM 11.45 Trends in colorectal oncology and clinical insights for the near future Rob Glynne-Jones, London, UK 12.15 LUNCH 13.45 VIDEO SESSION 14.15 SATELLITE SYMPOSIUM 15.00 COFFEE BREAK 15.30 The unsolved issue of TME: open, robotic, transanal, or laparoscopic – shining light on evidence and practice Des Winter, Dublin, IE Jim Khan, London, UK Brendan Moran, Basingstoke, UK 16.30 SATELLITE SYMPOSIUM 17.15 Lars Pahlman lecture Søren Laurberg, Aarhus, DK Wednesday, 30 November 2022 9.00 Advanced risk stratification in colorectal cancer – choosing wisely surgery and adjuvant therapy Philip Quirke, Leeds, UK 09.30 Predictors for Postoperative Complications and Mortality Ronan O‘Connell, Dublin, IE 10.00 Segmental colectomy versus extended colectomy for complex cancer Quentin Denost, Bordeaux, FR 10.30 COFFEE BREAK 11.00 Incidental cancer in polyp - completion surgery or endoscopy treatment alone? Laura Beyer-Berjot, Marseille, FR 11.30 SATELLITE SYMPOSIUM 12.00 Less is more – pushing the boundaries of full-thickness rectal resection Xavier Serra-Aracil, Barcelona, ES 12.30 LUNCH 14.00 Management of intestinal neuroendocrine neoplasia Frédéric Ris, Geneva, CH 14.30 Poster Presentation & Best Poster Award Michel Adamina, Winterthur, CH 15.00 SATELLITE SYMPOSIUM 15.45 COFFEE BREAK 16.15 Reoperative pelvic floor surgery – dealing with perineal hernia, reoperations, and complex reconstructions Guillaume Meurette, Nantes, FR 16.45 Salvage strategies for rectal neoplasia Roel Hompes, Amsterdam, NL 17.15 Beyond TME – technique and results of pelvic exenteration and sacrectomy Paris Tekkis, London, UK 19.30 FESTIVE EVENING Monday, 28 November 2022 09.50 Opening and welcome Jochen Lange, St.Gallen, CH 10.00 It is leaking! Approaches to salvaging an anastomosis Willem Bemelman, Amsterdam, NL 10.30 Predictive and diagnostic markers of anastomotic leak Andre D‘Hoore, Leuven, BE 11.00 SATELLITE SYMPOSIUM 11.45 Of microbes and men – the unspoken story of anastomotic leakage James Kinross, London, UK 12.15 LUNCH 13.45 Operative techniques to reduce anastomotic recurrence in Crohn’s disease Laura Hancock, Manchester, UK 14.15 Innovative approaches in the treatment of complex Crohn Diseases perianal fistula Christianne Buskens, Amsterdam, NL 14.45 To divert or not to divert in Crohn surgery – technical aspects and patient factors Pär Myrelid, Linköping, SE 15.15 COFFEE BREAK 15.45 Appendiceal neoplasia – when to opt for a minimal approach, when and how to go for a maximal treatment Tom Cecil, Basingstoke, Hampshire, UK 16.15 SATELLITE SYMPOSIUM 17.00 Outcomes of modern induction therapies and Wait and Watch strategies, Hope or Hype Antonino Spinelli, Milano, IT 17.30 EAES Presidential Lecture - Use of ICG in colorectal surgery: beyond bowel perfusion Salvador Morales-Conde, Sevilla, ES 18.00 Get-Together with your colleagues Industrial Exhibition Thursday, 1 December 2022 Masterclass in Colorectal Surgery Proctology Day