Background Adherence to inhaled therapy is key to effective COPD management; poor adherence is associated with suboptimal outcomes. While adherence may be more accurately measured in traditional double-blind randomised controlled trials (RCTs) than in effectiveness trials conducted in everyday clinical practice, the latter may more closely reflect “typical” patient adherence. Aim To describe adherence in SLS COPD, a 12 month open-label effectiveness RCT that evaluated initiating fluticasone furoate/vilanterol (FF/VI) vs continuing usual care (UC) in COPD patients in UK primary care. Methods Adherence was estimated by proportion of days covered (PDC; based on study medication prescribing data from patients’ electronic case report forms [eCRFs]/electronic health records [EHRs] during the study) and the MARS-A 9 questionnaire. Selected outcomes were descriptively analysed by PDC Results Mean PDC during the study was similar for FF/VI and UC; the proportion of patients with PDC≥80% was high in both groups (Table). Summary statistics showed little change in MARS-A 9 during the study and similar responses in both treatment arms. Clear relationships between PDC category and exacerbations, healthcare resource utilisation, and COPD Assessment Test were not observed. Conclusions In SLS COPD, adherence estimated by PDC was high and there was no clear association between PDC and outcomes. Limitations include adherence based on patients’ self-reporting and eCRF/EHR prescribing data. Funding GSK (HZC115151/NCT01551758). Please refer to page A260 for declarations of interest in relation to abstract P269.
