Medication adherence in gout: a systematic review.

OBJECTIVE: Recent data suggesting the growing problem of medication nonadherence in gout have called for the need to synthesize the burden, determinants, and impacts of the problem. Our objective was to conduct a systematic review of the literature examining medication adherence among patients with gout in real-world settings. METHODS: We conducted a search of Medline, Embase, International Pharmaceutical Abstracts, PsycINFO, and CINAHL databases and selected studies of gout patients and medication adherence in real-world settings. We extracted information on study design, sample size, length of followup, data source (e.g., prescription records versus electronic monitoring versus self-report), type of nonadherence problem evaluated, adherence measures and reported estimates, and determinants of adherence reported in multivariable analyses. RESULTS: We included 16 studies that we categorized according to methods used to measure adherence, including electronic prescription records (n = 10), clinical records (n = 1), electronic monitoring devices (n = 1), and self-report (n = 4). The burden of nonadherence was reported in all studies, and among studies based on electronic prescription records, adherence rates were all below 0.80 and the proportion of adherent patients ranged from 10-46%. Six studies reported on determinants, with older age and having comorbid hypertension consistently shown to be positively associated with better adherence. One study showed the impact of adherence on achieving a serum uric acid target. CONCLUSION: With less than half of gout patients in real-world settings adherent to their treatment, this systematic review highlights the importance of health care professionals discussing adherence to medications during encounters with patients.