Incidence and determinants of diabetes-related lower limb amputations in Ghana, 2010-2015 - A retrospective cohort study

Abstract

Background: Diabetes-related lower limb amputations (LLA) are associated with significant morbidity and mortality. Although the incidence has decreased over the past two decades in most High-Income Countries, the situation in Low-Middle Income Countries (LMIC), especially those in sub-Saharan Africa (SSA) is not clear. We have determined the incidence and determinants of diabetes-related LLA in Ghana. Methods: This was a tertiary-care-based retrospective cohort study involving patients enrolled in the diabetes clinic of Komfo Anokye Teaching Hospital, Ghana from 1st January 2010 to 31st December 2015 after a median follow-up of 4.2 years. Demographic characteristics and clinical variables at baseline were recorded. The primary outcome was new diabetes-related LLA in each year under study. Cox proportional hazard regression models were used to describe the associations of diabetes-related LLA. Results: The mean age at enrolment for the cohort was 55.9 ± 14.6 years, with a female preponderance (62.1%). The average incidence rate of diabetes-related LLA was 2.4 (95% CI:1.84-5.61) per 1000 follow-up years: increasing from 0.6% (95% CI:0.21-2.21) per 1000 follow up years in 2010 to 10.9% (95% CI:6.22-12.44) per 1000 follow-up years in 2015. Diabetes-related LLA was associated with increased age at enrollment (for every 10 year increase in age: HR: 1.11, CI: 1.06-1.22, p < 0.001), male gender (HR: 3.50, CI:2.88-5.23, p < 0.01), type 2 diabetes (HR 3.21, CI: 2.58-10.6, p < 0.001), high Body Mass Index (HR: 3.2, CI: 2.51-7.25 p < 0.001), poor glycemic control (for a percent increase in HbA1c, HR:1.11, CI:1.05-1.25, p = 0.03), hypertension (HR:1.14, CI:1.12-3.21 p < 0.001), peripheral sensory neuropathy (HR:6.56 CI:6.21-8.52 p < 0.001) and peripheral vascular disease (HR: 7.73 CI: 4.39-9.53, p < 0.001). Conclusion: The study confirms a high incidence of diabetes related-LLA in Ghana. Interventions aimed at addressing systemic and patient-level barriers to good vascular risk factor control and proper foot care for diabetics should be introduced in LMICs to stem the tide of the increasing incidence of LLA.