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

Abstract

Background/Objective : Diabetic foot ulcers (DFU) are associated with high morbidity and mortality globally. Mortality in patients hospitalized for DFU in Nigeria is unacceptably high. We sought to document contributory factors which predict mortality in patients hospitalized for DFU. Methods : Multi-centre Evaluation of Diabetic Foot Ulcer in Nigeria ( MEDFUN ), one-year 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. Co-morbid complications were documented. Results : Mean age 55.9 12.5 years.96.1% had type 2 diabetes (DM), mean duration of DM was 8.5 ± 5.7 years. Duration of ulcer was 39 days with a range of 28 to 54 days. 79.2% presented with at least grade 3 DFU. About one-fifth of the patients died (20.5%). Highest mortality among subjects with Wagner grade 5. Middle-aged subjects ( 45-64 years) had significantly higher mortality- odds ratio (OR) 5.107, Confidence interval (CI) of 1.429-18.252, and P-value 0.022. Variables significantly associated with mortality with the respective p- values are DM duration more than 120 months (0.008), ulcer duration > one month (0.013), ulcer severity of Wagner grade 3 and above (0.001), peripheral arterial disease (0.002), foot gangrene (< 0.001). Laboratory variables associated with mortality ; proteinuria (<0.001), positive blood cultures (<0.001), severe vascular stenosis (0.001), moderate vascular stenosis(< 0.001), Low HDL (< 0.001). Co-morbid complications significantly associated with mortality; shock at presentation (<0.001), anemia (0.034), cardiac failure (0.020), renal impairment (<0.001). Sepsis was the strongest predictor of mortality (adjusted OR 5.128; 95% CI 2.614 – 10.060) followed by renal impairment (adjusted OR 2.831; 95% C.I. for OR 1.346 – 5.953). Conclusions : Mortality among Nigerian diabetic patients admitted for DFU is high, univariate predictors of mortality: older age, higher Wagner grade (≥ 3) ulcer, longer duration of DM, longer duration of ulcer, peripheral arterial disease, foot gangrene, renal impairment, low HDL- cholesterol, anemia, shock, and cardiac failure. Renal impairment and positive blood culture were independent determinants of mortality.