Medication adherence among patients with gout: A systematic review and meta-analysis

Objective: In the management of chronic gout, a large proportion of patients need long-term management with urate lowering therapy (ULT). This study reviews medication adherence to ULT andsummarizes factors associated with adherence.Methods: We performed a systematic literature search for studies on adherence to ULT among goutpatients in PubMed, Embase, CINAHL, and PsycINFO. We conducted meta-analysis, with a random effectmodel, for the studies reporting the proportion of patients considered adherent to at least 80% ofprescribed medication or time taken. We explored potential sources of heterogeneity, includinggeographic area and measure of adherence. Narrative summaries were made for data on adherenceassessed/defined by Medication Event Monitoring System (MEMS)/pill-count or patient-reported,occurrence of a gap in therapy ≥30 days (non-persistence), and factors associated with adherence.Results: Of the 24 studies, 16 assessed adherence using prescription/claims data, two by the MEMS or pillcount, and six by patient-reported data. The pooled proportion of adherent patients (n ¼ 13) was 46%(95% CI: 41–51); 45% across studies conducted in the USA (n ¼ 8) and 48% in other countries (n ¼ 5).Adherence assessed by MEMS/pill count and patient-reported was much higher than by studies usingprescription/claims data. Non-persistence (n ¼ 6) ranged from 54% to 87%. Factors associated withadherence were investigated in 18 studies. Strong evidence for a positive association with older age,more comorbidities, and the presence of diabetes or hypertension was found.Conclusion: Medication adherence to ULT among gout patients was poor. Better insight into reasons andconsequences or poor adherence is needed