OBJECTIVES: Inadequate foot care among individuals with diabetes contributes to the risk of lower limb amputations (LLA). To understand the implications of sub-optimal treatment on the health care system, it is important to assess the costs associated with LLA. As each amputation event is likely subject to unique situational factors, costs estimates should address this heterogeneity with appropriate data and statistical methods. To assess whether published figures satisfy this criterion, we conducted a literature review of the costs of LLA in people with diabetes in the US.

METHODS: A systematic search was conducted using PubMed, the Tufts CEA registry, and AHRQ website to identify LLA studies in the US published after 2000. For studies satisfying the inclusion/exclusion criteria, we extracted and critically evaluated study characteristics (e.g., data sources, definitions, and methodology), underlying data characteristics (e.g., patients and event rates), and all cost estimates. All costs were inflated to 2016 US dollars.

RESULTS: The search identified 610 references, of which 15 satisfied the inclusion/exclusion criteria. These studies reported 27 cost estimates for 8 distinct categories of LLA (one study reported charges rather than costs and was excluded). Methodologies employed did not appear to adequately control for treatment heterogeneity and in some studies, documentation was poor. Ten studies reported costs irrespective of LLA type (i.e., did not distinguish between minor vs. major) with a range $10,103 to $67,773. Mean costs were $46,802 for 7 estimates classified as minor and $73,222 for 10 estimates of major amputations. Excluding one extreme outlier, the mean costs decreased to $16,355 and $55,874, respectively, but standard deviations remained large.

CONCLUSIONS: These findings suggest that existing estimates of LLA costs are methodologically deficient for use in estimating economic impact in the US. Additional costing work which addresses the heterogeneous nature of LLA is needed.