biostudies-literatureWarren SRIntramural NIH HHS441-8https://www.ebi.ac.uk/biostudies/studies/S-EPMC6178218biostudies-literatureUnknown10(3)<h4>Background</h4>Assessment of adherence to study medications is a common challenge in clinical research. Counting unused study medication is the predominant method by which adherence is assessed in outpatient clinical trials but it has limitations that include questionable validity and burdens on research personnel.<h4>Purpose</h4>To compare capsule counts, patient questionnaire responses, and plasma drug levels as methods of determining adherence in a clinical trial that had 2056 participants and used centralized drug distribution and patient follow-up.<h4>Methods</h4>Capsule counts from study medication bottles returned by participants and responses to questions regarding adherence during quarterly telephone interviews were averaged and compared. Both measures were compared to plasma Clinical trials (London, England)Medication adherence assessment in a clinical trial with centralized follow-up and direct-to-patient drug shipments.PMC6178218Z99 AG999999Huang GDTaylor ZRayne AYoung EMarkulin MDetre KKaufman JDurant LMcAllister BContreras GCxypoliski RFlanagin GPiexoto ANagaria AO'Brien GLanghoff ETitus LCooke CSingleton AMartin MIngram KJaimes EHartigan PGrunsten NRewakowski CSimmons CRehman SHelmuth MJamison RSanders PLohr JLevinsky NSchmid SYohe LDev DShea MCook IFinnigan TRenft AGaziano JNeiderman JShanklin NShannon TAllore HClegg LAzcona-Vilchez CAntonelli MJones ELopez RKasl SFeldman GDay JMotulsky ALevi MJones DBelanger KFeldman RBest NSinks JThomson SSalai PSachs NWalczyk JCastrillon ZDixon TZellner SWingo CPastoriza ERosado CSteffe JOtterness SWall BCampbell HMO'Leary TJJamison RLStehman-Breen CJoyner SBeckwith DAbdallah JPatterson RCheung ACohen DDeLorenzo ASajgure DGreene TMarottoli RGuarino PDAgarwal RMehta RSaklayen MWarren SPaul RSchmidt DRaisch DJasinski DBrown BNugent-Carney JBetcher SWiegmann TPopli SRaisch DWGoldfarb DKaelin KMullaney SGuarino PKopple JChonchol MBey-Knight LAbu-Hamdan DWarren SRVeterans Affairs Site InvestigatorsLewis RPascual EKulivan CLindner AKaufman JSTyrrell DRust JPalevsky PVeneck DGeorgette GShook SModersitzki FAnderson SBadgett CCrowley SFucile NPeduzzi PKlag MBasu ADolson GDingsdale JSheriff HTasby GRaymond JKing KSallustio JPalant CJohnson HPerry EHolmes KZeman MSmith DBlumenthal SSather MNeff HPetrokaitis EGoldfarb DSLinnerud PBatuman VJoncas CCampbell HSmith NAnderson MDibbs EKillian DFarrell WMiller RTPerry MPastore NGaziano JMMa KJobes EZuluaga AfalseMedication adherence assessment in a clinical trial with centralized follow-up and direct-to-patient drug shipments.<h4>Background</h4>Assessment of adherence to study medications is a common challenge in clinical research. Counting unused study medication is the predominant method by which adherence is assessed in outpatient clinical trials but it has limitations that include questionable validity and burdens on research personnel.<h4>Purpose</h4>To compare capsule counts, patient questionnaire responses, and plasma drug levels as methods of determining adherence in a clinical trial that had 2056 participants and used centralized drug distribution and patient follow-up.<h4>Methods</h4>Capsule counts from study medication bottles returned by participants and responses to questions regarding adherence during quarterly telephone interviews were averaged and compared. Both measures were compared to plasma 2013-01-01T00:00:00Z20132025-04-18T13:30:35.483Z2019-03-27T00:02:28ZS-EPMC61782182181358310.1177/1740774511410331