Life expectancy of patients with diabetic foot sepsis post-lower extremity amputation at a regional hospital in a South African setting. A retrospective cohort study

Abstract

BACKGROUND : Diabetes foot sepsis (DFS) is the leading cause of amputation of lower extremities. Over 50 % of patients who have had major lower extremity amputation due to DFS are dead within 4 years following the procedure. AIM : To determine the life expectancy of patients following amputation for DFS at a regional hospital in South Africa. METHODS : We conducted an audit of patients who had DFS and were admitted over a 5-year period. The duration from admission to time of death was recorded in days. Occurrence of death was confirmed from family members of the deceased using structured telephonic interview questionnaires. Categorical findings were summarized using actual counts and percentages and compared using either the Chi-square or Fisher's exact test. We used the mean with standard deviation or median and range to compare parametric and non-parametric continuous data, respectively. The Shapiro-Wilk test was used to test normality of data. Multivariate logistic regression was done to establish factors that were strongly associated with the mortalities. Adjusted survival curves were added to compare the rate of occurrence of mortality between males and females with age as a confounder. Statistical significance was set at a p-value below 0.05. RESULTS : 197 were found of which 100 % of participants had Type 2 diabetes mellitus and 63.5 % were males. Associated comorbidities included hypertension in 73.6 %, obesity in 66 %, alcohol use in 64.5 % and smoking in 58.4 %. 190 participants had an amputation and 19.3 % died. CONCLUSION : DFS was more common in males and 96 % of the patients had an amputation. Mortality rate within 4 years following amputation was 19.3 % and was higher in females and individuals with multiple comorbidities.