Comparing Active Case-Finding Strategies and Passive Case-Finding for Tuberculosis: An Umbrella Review of Current Evidence

Abstract Background Tuberculosis (TB) remains a global health challenge. Recent studies have compared active case-finding (ACF) with passive case-finding (PCF) and various ACF strategies, assessing diagnostic yield, treatment outcomes, cost-effectiveness, and overall TB control impact. However, evidence remains fragmented due to methodological heterogeneity. Methods To assess how ACF compares to PCF and to different ACF strategies in improving TB detection, treatment outcomes, and overall T control, we conducted an umbrella review of systematic reviews and meta-analyses published through March 30, 2025, evaluating ACF versus PCF and different ACF strategies across diverse settings. Key outcomes included diagnostic yield, treatment outcomes, cost-effectiveness, and epidemiological impact. Methodological quality was assessed using the AMSTAR 2 tool. Results Twelve systematic reviews and meta-analyses met the inclusion criteria, with methodological quality ranging from low to moderate. ACF may be more effective than PCF in increasing TB detection rates, especially in high-risk populations such as migrants, people living with HIV, drug users, and close contacts of TB patients. Treatment outcomes among ACF-identified cases were mixed, with concerns about pre-treatment loss to follow-up. ACF interventions were cost-effective in high-prevalence settings, though their cost-effectiveness varied depending on implementation coverage, intensity, and the screening tools. However, evidence linking ACF to sustained increases in national routine TB notifications was limited. Conclusion While ACF is effective for targeted detection in high-risk groups and often cost-effective in high-burden settings, its broader epidemiological impact remains uncertain. Future TB control strategies should prioritize integrated, context-sensitive approaches that combine active and passive case detection, and future research should focus on evaluating ACF interventions based on their ability to achieve sustained reductions in TB prevalence and transmission over time. Take home message: Despite extensive research on ACF versus PCF in TB control, the fragmented and methodologically diverse evidence necessitates a comprehensive synthesis to inform global policies and practices. What this study adds - ACF improves TB detection in high-risk groups, but its effectiveness and cost-effectiveness are context-dependent. Cost-effective screening may enable early detection and treatment, reducing the TB burden on healthcare systems. ACF may be effective and cost effective in high-risk populations and at observational level but its epidemiological impact at national level is unclear How this study might affect research, practice or policy - This study highlights the need for targeted TB screening in high-risk groups to reduce TB incidence, support for continued investment in cost-effective strategies, and the enhancement of health outcomes through integrated approaches and supportive measures.