Predictors of intra-hospital mortality in patients with diabetic foot ulcers in Nigeria: data from the MEDFUN study.

Background: Diabetic foot ulcers (DFU) are associated with high morbidity and mortality globally. Mortality in patients hospitalized for DFU in Nigeria is unacceptably high. This study was undertaken to determine factors that predict mortality in patients hospitalized for DFU in Nigeria.

Methods: The current study was part of Multi-centre Evaluation of Diabetic Foot Ulcer in Nigeria (MEDFUN), an observational study conducted in six tertiary healthcare institutions across the 6 geopolitical zones of Nigeria. Consecutive type 1 or 2 diabetic patients hospitalized for DFU who consented to participate were recruited and subjected to relevant clinical, biochemical, and radiological assessments and multidisciplinary care until discharge or death. Data for type 1 diabetes mellitus (DM) patients were expunged from current mortality analysis due to their small number.

Results: Three hundred and twenty-three type 2 DM subjects with mean age and mean duration of DM of 57.2 ± 11.4 years and 8.7 ± 5.8 years respectively participated in this study. The median duration of ulcers was 39 days with a range of 28 to 54 days and the majority (79.9%) presented with advanced ulcers of at least Wagner grade 3. Mortality of 21.4% was recorded in the study, with the highest mortality observed among subjects with Wagner grade 5. Variables significantly associated with mortality with their respective p values were DM duration more than 120 months (p 0.005), ulcer duration > 1 month (p 0.020), ulcer severity of Wagner grade 3 and above (p 0.001), peripheral arterial disease (p 0.005), proteinuria (p < 0.001), positive blood cultures (p < 0.001), low HDL (p < 0.001), shock at presentation (p < 0.001), cardiac failure (p 0.027), and renal impairment (p < 0.001). On Multivariate regression analysis, presence of bacteraemia (OR 5.053; 95% CI 2.572-9.428) and renal impairment (OR 2.838; 95% CI 1.349-5.971) were significantly predictive of mortality independent of other variables.

Conclusions: This study showed high intra-hospital mortality among patients with DFU, with the majority of deaths occurring among those with advanced ulcers, bacteraemia, cardiac failure, and renal impairment. Prompt attention to these factors might help improve survival from DFU in Nigeria.