Objective: To determine the effect of comorbid depression on the risk of amputation in people with diabetes.

Study design: We conducted a systematic review and meta-analysis of available published literature on the effect of depression on amputation risk, in people with diabetes. Several databases were searched on July 29^th 2014 including PubMed, CINAHL, EMBASE, MEDline, the Cochrane library and PsychARTICLES using the key terms ‘diabetes’, ‘amputation’ and ‘depression’. MeSH (Medical Subject Heading) terms and truncation were used as appropriate. Two reviewers screened titles for eligible studies, cross-checked reference lists and hand-searched relevant journals.

Study selection: Published randomised and observational studies were considered eligible for this study. Two reviewers performed the data abstraction using an agreed data abstraction form and assessed study quality. Data on the study design, population characteristics, interventions, outcomes, confounders and risk estimates were extracted.

Methods A meta-analysis was performed using both fixed and random-effects models where appropriate generating an overall pooled hazard ratio (HR) with 95% confidence interval (CI) in Review Manager software version 5. X.

Results Six studies met the inclusion criteria for the systematic review and included data on 765,921 patients with diabetes, including 87,892 (11.5%) with diabetes and comorbid depression and provided sufficient data to be included. The studies were conducted in the U. K., U. S. A. and Sweden. Three studies were included in the meta-analysis. The studies were heterogeneous (I² = 93%, P = 0.0003) in design and population and a random – effects model was used. Comorbid depression did not significantly affect hazard ratio on amputation, in a meta-analysis of available data. The pooled HR of risk of amputation due to the exposure of depression was 2.13 (95% CI 0.85–5.35).

Conclusion The overall findings based on available evidence, conclude that there is insufficient evidence to determine if comorbid depression increased the risk of amputation, in people with diabetes.