What works and why in the identification and referral of adults with comorbid obesity in primary care: A realist review

Primary care practitioners (PCPs) are well placed to identify individuals with obesity and weight-related comorbidities and to refer them to weight management services (WMS), but this does not often happen in practice. In this realist review, we searched six databases for intervention studies targeted at PCPs to improve the identification and referral of adults with comorbid obesity. Realist analysis was used to identify context-mechanism-outcome (CMO) configurations across 30 included papers (reporting on 27 studies). Most studies used multiple intervention strategies, categorised into: (a) training, (b) tools to improve identification, (c) tools to improve ease of referral, (d) audit/feedback, (e) working in networks/quality circles, and (f) other. The realist synthesis identified 12 mechanisms through which interventions work to improve identification and referral, including increasing knowledge about obesity and awareness of and confidence in WMS among practitioners, improved communication and trust between practitioners and WMS, and higher priority given to weight management among primary care teams. The theory of "candidacy" (a person's eligibility for medical attention and intervention) provided a robust explanatory framework but required refinement: (a) to take account of the different services (primary care and weight management) that patients must navigate to access support; and (b) to acknowledge the importance of wider contextual factors.