Association of comorbid depression with inpatient outcomes in critical limb ischemia

There is a growing body of evidence that peripheral artery disease (PAD) may be impacted by depression. The objective of this study is to determine whether outcomes, primarily major amputation, differ between patients with depression and those without who presented to hospitals with critical limb ischemia (CLI), the end-stage of PAD. A retrospective cohort of patients hospitalized for CLI during 2012 and 2013 was identified from the National Inpatient Sample (NIS) using ICD-9 codes. The primary outcome was major amputation and secondary outcomes were length of stay and other complications. The sample included 116,008 patients hospitalized for CLI, of whom 10,512 (9.1%) had comorbid depression. Patients with depression were younger (64 ± 14 vs 67 ± 14 years, p < 0.001) and more likely to be female (55% vs 41%, p < 0.001), white (73% vs 66%, p < 0.001), and tobacco users (46% vs 41%, p < 0.001). They were also more likely to have prior amputations (9.8% vs 7.9%, p < 0.001). During the hospitalization, the rate of major amputation was higher in patients with comorbid depression (11.5% vs 9.1%, p < 0.001). In multivariable analysis, excluding patients who died prior to/without receiving an amputation (n = 2621), comorbid depression was associated with a 39% increased odds of major amputation (adjusted OR 1.39, 95% CI 1.30, 1.49; p < 0.001). Across the entire sample, comorbid depression was also independently associated with a slightly longer length of stay (β = 0.199, 95% CI 0.155, 0.244; p < 0.001). These results provide further evidence that depression is a variable of interest in PAD and surgical quality databases should include mental health variables to enable further study.