Effect of drug cost-sharing change on nonadherence to essential medications for acute coronary syndrome: a population based natural experiment

ISPOR&19th&Annual&European&Congress& ! ! EFFECT OF DRUG COST-SHARING CHANGE ON NONADHERENCE TO ESSENTIAL MEDICATIONS FOR ACUTE CORONARY SYNDROME: A POPULATION BASED NATURAL EXPERIMENT González B1, Librero J2, Peña-Logobardo LM3, Bauer S4, GarcíaSempere A4, Puig-Junoy J5, Oliva Moreno J6, Peiró S2, SanfélixGimeno G2 1University of Las Palmas de GC,, Las Palmas de GC, Spain, 2Center for Public Health Research (CSISP-FISABIO);Red de Investigación en Servicios de Salud en Enfermedades Crónicas, Valencia, Spain, 3Castilla La Mancha University, Toledo, Spain, 4Center for Public Health Research (CSISP-FISABIO), Valencia, Spain, 5Pompeu Fabra University, Barcelona, Spain, 6University of Castilla-La Mancha, Toledo, Spain ! &! Background! In! July! 2012,! the! Spanish! drug! cost9sharing! scheme! was! reformed,! providing! the! opportunity! to! evaluate! the! consequences!of!this!change!on!patient!adherence.!The!aim!of! this!study!was!to!assess!the!impact!of!the!cost9sharing!change!on! medication!adherence!in!patients!with!acute!coronary!syndrome! (ACS)!in!the!Spanish!region!of!Valencia.! Methods! Population9based! retrospective! cohort! of! all! patients! 35! years! old!and!over!discharged!after!an!ACS!from!public!hospitals!in!the! Valencia!region!during!200992011,!followed!until!2013.!We!used! Difference!in!Difference!to!estimate!the!policy!change!effect!on! adherence!to!antiplatelet,!beta9blockers,!ACEI/ARB!and!statins!of! a! control! group! –! low! income! working! population! who! did! not! change! their! status! (40%! coinsurance,! unchanged)! 9! and! two! intervention!groups:!pensioners!(who!moved!from!full!coverage! to! 10%! coinsurance)! and! middle! to! high! income! working! population,!for!whom!coinsurance!grew!from!40%!to!50%!or!60%! of!drug!cost.! Results! No! significant! differences! in! non9adherence! between! intervention!and!control!groups!were!found!for!medications!with! low! price! and! low! patient! maximum! coinsurance,! such! as! antiplatelet! and! beta9blockers.! For! ACEI/ARB! and! statins,! the! change! had! an! immediate! effect! in! the! proportion! of! non9 adherence!in!the!pensioner!group!as!compared!with!the!control! group! (6.8%! and! 8.3%! increase! respectively,! p<0.01! for! both).! Non9adherence!to!statins!significantly!increased!after!the!reform! for! the! middle! to! high! income! group! vs.! control! group! (7.8%! increase,!p<0.01).!However,!those!effects!were!transitory.! Conclusions! Coinsurance!changes!may!lead!to!increased!non9adherence!to! proven,!effective!therapies,!especially!for!higher!priced!agents! with!higher!patient!cost!share.!Adherence!was!already!sub9 optimal!before!the!cost9sharing!policy!change,!with!a!clear!cost!/! income!gradient.!Consideration!should!be!given!to!fully!exempt! high!risk!patients!from!drug!cost9sharing.! !