Objectives Consistent reports of suboptimal treatment adherence among patients with inflammatory arthritis underscore the importance of understanding how adherence can be promoted and supported. Our objectives were to identify and classify adherence interventions; and assess the evidence on the effects of adherence interventions on outcomes of patients with rheumatic diseases.

Methods We conducted a mapped search of Medline, Embase and International Pharmaceutical Abstract databases to identify studies meeting inclusion criteria of: (1) patient population with inflammatory arthritis; (2) evaluation of an intervention or programme targeting medication adherence directly or indirectly; (3) reporting of one or more measures of medication adherence and disease outcome; (4) publication in English, French or Spanish. For our first objective, we applied a structured framework to classify interventions according target (patient vs provider), focus (educational vs behavioural vs affective), implementation (generalised vs tailored), complexity (single vs multifaceted) and provider. For the second objective, we appraised the evidence of effects of interventions on adherence and disease outcomes.

Results We identified 23 studies reporting adherence interventions that directly or indirectly addressed treatment adherence in rheumatic diseases and further appraised included RCTs. Interventions that were shown to impact adherence outcomes were generally interventions directed at adherence, tailored to patients and delivered by a healthcare provider. For interventions that were not shown to have impacts, reasons may be those related to the intervention itself, patient characteristics or study methodology.

Conclusions Our systematic review shows limited research on adherence interventions in rheumatic diseases with inconsistent impacts on adherence or disease outcome.