Diabetes mellitus linked to higher SSI risk after hernia repair, other factors not significant

BackgroundSurgical site infection (SSI) and hernia recurrence are among the most common and impactful complications following abdominal wall hernia repair. Identifying patient-related risk factors is essential for improving outcomes and guiding perioperative management.MethodsA systematic review and meta-analysis were conducted in accordance with PRISMA 2020 and AMSTAR 2 guidelines. PubMed, Embase, Scopus, CNKI,Wanfang, and VIP were searched up to September 20,2025. Eligible studies included randomized controlled trials, cohort, and case-control studies that reported associations between patient-related variables and SSI or recurrence after hernia repair. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models. Beyond I2, the 95% prediction interval (PI) was utilized as the primary metric to evaluate the absolute dispersion of true effects. Risk of bias was assessed using the Newcastle–Ottawa Scale (NOS).ResultsA total of 11 studies involving 97,428 patients were included. No significant associations were observed for female sex (OR: 1.05, 95% CI: 0.77–1.42, P = 0.77; 95% PI: 0.48–2.29), obesity (OR: 1.15, 95% CI: 0.78–1.68, P = 0.48; 95% PI: 0.37–3.55), COPD (OR: 0.95, 95% CI: 0.47–1.92, P = 0.88; 95% PI: 0.14–6.25), or immunosuppressive therapy (OR 0.90, 95% CI: 0.38–2.14, P = 0.81). Although diabetes mellitus reached nominal statistical significance (OR: 1.46, 95% CI: 1.01–2.11, P = 0.04), its wide 95% PI (0.55–3.90) suggested considerable inconsistency across cohorts. Similarly, higher ASA classification (>3 vs.