Time-Dependent Impact of Diabetes on Mortality in Patients After Major Lower Extremity Amputation

Abstract

OBJECTIVETo estimate the impact of diabetes on mortality in patients after first major lower extremity amputation (LEA).RESEARCH DESIGN AND METHODSUsing claims data of a nationwide statutory health insurance, we assessed all deaths in a cohort of all 444 patients with a first major LEA since 2005 (71.8% male; mean age 69.1 years; 58.3% diabetic; 43% with amputation above the knee) up to 2009. Using Cox regression, we estimated the time-dependent hazard ratios to compare patients with and without diabetes.RESULTSThe cumulative 5-year mortality was 68% in diabetic and 59% in nondiabetic individuals. In the first course, mortality was lower in diabetic compared with nondiabetic patients. Later, the diabetes risk increased yielding crossed survival curves after 2 to 3 years (time dependency of diabetes; P = 0.003). Age- and sex-adjusted hazard ratios for diabetes were as follows: 0–30 days: 0.50 [95% CI 0.31–0.84]; 31–60 days: 0.60 [0.25–1.41]; 61 days to 6 months: 0.75 [0.38–1.48]; >6–12 months: 1.27 [0.63–2.53]; >12–24 months: 1.65 [0.88–3.08]; >24–36 months: 2.02 [0.80–5.09]; and >36–60 months: 1.91 [0.70–5.21]. The pattern was similar in both sexes. In the full model, significant risk factors for mortality were age (1.05; 1.03–1.06), amputation above the knee (1.50; 1.16–1.94), and quartile category 3 or 4 of the number of prescribed medications (1.64; 1.12–2.40 and 1.76; 1.20–2.59). Further adjustment for comorbidity did not alter the results.CONCLUSIONSIn this population-based study, we found a time-dependent mortality risk of diabetes following first major LEA, which may be in part a result of a healthier lifestyle in diabetic patients or the access to specific treatment structures in diabetic individuals.

Predictors of in-hospital mortality following major lower extremity amputations in type 2 diabetic patients using artificial neural networks

“…Our IHM of 10.0% is consistent with previously reported data ranging from 7% to 12.4% [7, 10, 30–33]. Investigation of underlying influences from health services, surgical decisions and patient motivations behind decisions to amputate might help to explain some of the differences in post-operative mortality rates between studies [34].…”

“…The effect of advancing age on IHM is also highlighted in this study, as has been well established by other authors [7, 10, 30]. Older age is associated with high prevalence of comorbid conditions, mainly cardiovascular and renal diseases, both of which are also associated with higher mortality rates [32, 35].…”

“…However, a major lower extremity amputation (LEA) is associated with a reduction of long-term survival and quality of life [6, 7]. …”

Survival of diabetes patients with major amputation is comparable to malignant disease

“…A major amputation was associated with an adverse outcome and reduced long-term survival. 18,19 These results are further supported by the studies of Larsson et al 12 and Faglia et al 20 We observed a highly significant difference in the comparison of long-term survival between groups II and III. The median survival rate in group III was 15 months longer than in group II.…”

Cost of diabetic foot disease to the National Health Service in England

“…Diabetic foot disease is associated with impaired quality of life [4,5] and high mortality. After primary ulceration, 5-year mortality rates have been estimated to be 42-44% and after amputation they are estimated to be 68-79% [6][7][8][9].…”