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

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 and summarizes factors associated with adherence.

We performed a systematic literature search for studies on adherence to ULT among gout patients in PubMed, Embase, CINAHL, and PsycINFO. We conducted meta-analysis, with a random effect model, for the studies reporting the proportion of patients considered adherent to at least 80% of prescribed medication or time taken. We explored potential sources of heterogeneity, including geographic area and measure of adherence. Narrative summaries were made for data on adherence assessed/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.

Of the 24 studies, 16 assessed adherence using prescription/claims data, two by the MEMS or pill count, and six by patient-reported data. The pooled proportion of adherent patients (n = 13) was 46% (95% CI: 41-51); 45% across studies conducted in the USA (n = 8) and 48% in other countries (n = 5). Adherence assessed by MEMS/pill count and patient-reported was much higher than by studies using prescription/claims data. Non-persistence (n = 6) ranged from 54% to 87%. Factors associated with adherence 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.

Medication adherence to ULT among gout patients was poor. Better insight into reasons and consequences or poor adherence is needed.