Regional Disparities and Temporal Trends in Rheumatic Heart Disease Burden in Nepal: A Systematic Review and Meta-Analysis

Background Rheumatic heart disease remains a major cause of preventable cardiovascular morbidity and mortality in low- and middle-income countries. We conducted a systematic review and meta-analysis to estimate the prevalence of rheumatic heart disease, examine temporal and geographic disparities, and assess the certainty of the available evidence. Methods We systematically reviewed observational studies reporting rheumatic heart disease prevalence with extractable numerators and denominators and echocardiography-confirmed diagnoses. Quality was appraised using the Joanna Briggs Institute (JBI) checklist. Pooled prevalence was estimated using generalized linear mixed models (GLMM) with logit transformation (random effects; back-transformed). Subgroup analyses compared Kathmandu-based studies with non-Kathmandu studies; meta-regression examined publication year, log(sample size), and region. The certainty of evidence was assessed using GRADE. Results Ten studies (209,815 participants and 5,440 cases) were included. The pooled prevalence was 3.1% (95% CI 1.6-5.8%) with a wide prediction interval of 0.3-28.5%, indicating that the true prevalence in Nepalese settings could plausibly vary from very low to very high. Heterogeneity was extreme (I^2 = 99.8%). Excluding the nationwide study, the prevalence was 1.1% (0.9-1.3%) in Kathmandu and 7.2% (3.7-13.3%) in non-Kathmandu (p < 0.001). Meta-regression showed a rising temporal trend (beta = 0.092, p = 0.001) and lower prevalence in larger samples (beta = -0.79, p < 0.001); the multivariable model explained about 85% of between-study heterogeneity. Egger's test suggested possible small-study effects (p = 0.096). GRADE certainty was low to moderate and downgraded for inconsistency and imprecision. Conclusion Rheumatic heart disease remains highly prevalent in Nepal, with a six-fold higher prevalence outside Kathmandu than in urban populations, and no evidence of decline over three decades. These findings call for urgent integration of RHD prevention, community-based echocardiographic screening, and equitable access to prophylaxis and surgical care into Nepal's decentralized health system.