Regional healthcare services and rates of lower extremity amputation related to diabetes and peripheral artery disease: an ecological study

Background — The care necessary to prevent amputation from diabetes and peripheral artery disease (PAD) remains disjointed in many jurisdictions. To help inform integrated regional care, this study explores the correlation between regional healthcare services and rates of lower extremity amputation.

Methods — This ecological study included 14 administrative health regions in Ontario, Canada. All diabetes- or PAD-related major (above ankle) amputations (Apr. 1, 2007, to Mar. 31, 2017) were identified among residents 40 years of age and older. For each region, age-and sex-adjusted amputation rates were calculated as well as per capita counts of key health providers (podiatrists and chiropodists, as well as surgeons) and healthcare utilization among study patients in the year before the first major amputation (physician visits, publicly funded podiatry visits, emergency department visits, hospital admissions, home care nursing, minor amputation, limb revascularization).

Results — A total of 11 658 patients with major amputation were identified (of whom 79.2% had diabetes and 96.5% had PAD). There was wide regional variation in amputation rates: 2.53 to 11.77 per 100 000 person-quarters. At a regional level, the proportion of study patients who received revascularization showed the strongest negative correlation with amputation rates. The regional proportion of study patients who saw a vascular surgeon showed the strongest negative correlation with amputation rates, relative to other health provider visits. Other measures of healthcare utilization among patients correlated poorly with regional amputation rates, as did the regional provider counts. The results were similar when we restricted the analysis to diabetes-related amputations.

Interpretation — Amputation rates related to diabetes and PAD vary widely across Ontario. Access to vascular assessment and revascularization must be integrated into regional amputation prevention efforts.