Global mortality of diabetic foot ulcer: A systematic review and meta‐analysis of observational studies

AIM: To estimate the long-term mortality and risk factors in patients with diabetic foot ulcer (DFU). METHODS: We systematically searched Medline (PubMed), Embase, Scopus, Web of Science, Cochrane Library, China Science and Technology Journal Database (CQVIP), China National Knowledge Infrastructure, the Chinese Biomedical Literature Database (SinoMed) and Wanfang Data from 1 January 2011 to 31 July 2022. All observational studies that reported long-term mortality of patients with DFU were included. Random effect models were used to pool the reconstructed participant data from Kaplan-Meier curves. The primary outcome was the long-term survival of patients with DFU. An aggregate data meta-analysis was also performed. RESULTS: We identified 34 studies, with 124 376 participants representing 16 countries, among whom there were 51 386 deaths. Of these, 27 studies with 21 171 patients were included in the Kaplan-Meier-based meta-analysis. The estimated Kaplan-Meier-based survival rates were 86.9% (95% confidence interval [CI] 82.6%-91.5%) at 1 year, 66.9% (95% CI 59.3%-75.6%) at 3 years, 50.9% (95% CI 42.0%-61.7%) at 5 years and 23.1% (95% CI 15.2%-34.9%) at 10 years. The results of the aggregate data-based meta-analysis were similar. Cardiovascular disease and infection were the most common causes of death, accounting for 46.6% (95% CI 33.5%-59.7%) and 24.8% (95% CI 16.0%-33.5%), respectively. Patients with older age (per 1 year, hazard ratio [HR] 1.054, 95% CI 1.045-1.063), peripheral artery disease (HR 1.882, 95% CI 1.592-2.225), chronic kidney disease (HR 1.535, 95% CI 1.227-1.919), end-stage renal disease (HR 3.586, 95% CI 1.333-9.643), amputation (HR 2.415, 95% CI 1.323-4.408) and history of cardiovascular disease (HR 1.449, 95% CI 1.276-1.645) had higher mortality risk. CONCLUSIONS: This meta-analysis found that the overall mortality of DFU was high, with nearly 50% mortality within 5 years. Cardiovascular disease and infection were the two leading causes of death.