Clinical interventions to improve adherence to urate-lowering therapy in patients with gout: a systematic review

The aim of this study was to systematically review and compare the quantitative effect of clinical interventions designed to improve adherence to urate-lowering therapy. MEDLINE, Embase, CINAHL, Scopus and Web of Science were searched for interventional studies reporting quantitative adherence to urate-lowering therapy information as an endpoint. Intervention details, quantitative adherence information, clinical outcome and cost-effectiveness data were extracted. Risk of bias was assessed. From 4721 records, 11 studies (3 randomised and 8 observational) met the inclusion criteria. Pharmacist- and nurse-led interventions were described, involving a mixture of patient education, telephone or mobile texting reminders, and medication blister packing. Quantitative adherence information was obtained using methods such as patient self-reporting and pharmacy-dispensing data. Most studies had a moderate-to-high risk of bias. Two of the three randomised studies reported improvement in adherence between the intervention and control groups, including a 13% increase in the mean proportion of days covered >0.8 [341/681 participants (50%) versus 289/782 participants (37%)] and an 88% increase in achieving a high Medicine Taking Behaviour questionnaire score [37/42 participants (88.1%) versus 0/40 participants (0%)]. Four of the eight observational studies reported improved adherence from baseline (ranging from 33% to 91% based on the longitudinal change in adherence metrics reported). A comparison of the different types of interventions was not feasible due to the heterogeneity between study designs and adherence metrics used. These findings support the need for more interventional studies to be conducted to aid adherence management.