Improving case-finding of long-term health problems in disadvantaged communities: A Policy-focused Evidence Brief.

Current challenges: Case finding, which actively identifies undiagnosed conditions, is key to tackling the growing chronic disease burden, especially in disadvantaged groups. Diseases like type 2 diabetes, cardiovascular disease, and chronic obstructive pulmonary disease already cause millions of preventable deaths, with numbers rising due to aging populations, urbanization, and widening inequalities. The poorest communities bear the heaviest load, with higher disease rates and lower diagnosis. Traditional healthcare models, which wait for patients to seek care, leave millions undiagnosed and untreated. Proactive case finding is a proven way to reduce disparities, improve outcomes, and ease the strain on healthcare systems. Key evidence to inform policy: This review identified two main approaches: targeted searches of primary care electronic health records (EHRs) to identify and engage high-risk individuals, and opportunistic screening in community, workplace, and emergency department settings. Systematic reviews and smaller observational studies, predominantly from high-income healthcare systems, support community-based health checks in trusted venues, workplace hypertension screening, and follow-up of elevated blood pressure readings in emergency departments, though evidence for these approaches is more limited. A stepped-wedge RCT found that targeted outreach nearly doubled diagnosis and treatment rates for cardiovascular risk factors compared with opportunistic case-finding (19.7% vs 10.8%). Meta-analyses of over 480,000 women found that self-sampling approximately doubled cervical screening uptake, with uptake increasing threefold when combined with community health worker support among under-screened ethnic minority and socioeconomically disadvantaged women. A cluster-randomised trial of over 74,000 participants showed that active case-finding using symptom questionnaires and handheld flowmeters identified four times more undiagnosed COPD than opportunistic screening, and was cost-effective at £16,596 per QALY gained. Further considerations and implications: This review identifies targeted case-finding in underserved communities as an evidence-based, high-impact strategy for early detection of chronic disease, provided it is integrated with sufficient downstream diagnostic and treatment capacity.