Diabetes mellitus is associated with increased risk of surgical site infections: A meta-analysis of prospective cohort studies.

BACKGROUND AND OBJECTIVE: Observational studies have suggested an association between diabetes mellitus and the risk of surgical site infections (SSIs), but the results remain inconclusive. We conducted a meta-analysis of prospective cohort studies to elucidate the relationship between diabetes mellitus and SSIs. METHODS: We searched PubMed, Embase, and Web of Science databases and reviewed the reference lists of the retrieved articles to identify relevant studies. Associations were tested in subgroups representing different patient characteristics and study quality criteria. The random-effect model was used to calculate the overall relative risk (RR). RESULTS: Fourteen prospective cohort studies (N = 91,094 participants) were included in this meta-analysis, and the pooled crude RR was 2.02 (95% confidence interval, 1.68-2.43) with significant between-study heterogeneity observed (I(2) = 56.50%). Significant association was also detected after we derived adjusted RRs for studies not reporting the adjusted RRs and calculated the combined adjusted RR of the 14 studies (RR, 1.69; 95% confidence interval, 1.33-2.13). Results were consistent and statistically significant in all subgroups. Stratified analyses found the number of confounders adjusted for, sample size, and method of diabetes case ascertainment might be the potential sources of heterogeneity. Sensitivity analysis further demonstrated the robustness of the result. CONCLUSIONS: This meta-analysis suggests diabetes mellitus is significantly associated with increased risk of SSIs. Future studies are encouraged to reveal the mechanisms underlying this association.