Survival analysis in amputees based on physical independence grade achievement

Survival implications of achieving different grades of physical independence after lower extremity amputation are unknown.

To identify thresholds of physical independence achievement associated with improved 6-month survival and to identify and compare other risk factors after removing the influence of the grade achieved.

Data were combined from 8 administrative databases. Grade was measured on the basis of 13 individual self-care and mobility activities measured at inpatient rehabilitation discharge.

Ninety-nine US Department of Veterans Affairs Medical Centers.

Retrospective longitudinal cohort study of 2616 veterans who underwent lower extremity amputation and subsequent inpatient rehabilitation between October 1, 2002, and September 30, 2004.

Cumulative 6-month survival after rehabilitation discharge.

The 6-month survival rate (95% confidence interval [CI]) for those at grade 1 (total assistance) was 73.5% (70.5%-76.2%). The achievement of grade 2 (maximal assistance) led to the largest incremental improvement in prognosis with survival increasing to 91.1% (95% CI, 85.6%-94.5%). In amputees who remained at grade 1, the 30-day hazards ratio for survival compared with grade 6 (independent) was 43.9 (95% CI, 10.8-278.2), sharply decreasing with time. Whereas metastatic cancer and hemodialysis remained significantly associated with reduced survival (both P < or = .001), anatomical amputation level was not significant when rehabilitation discharge grade and other diagnostic conditions were considered.

Even a small improvement to grade 2 in the most severely impaired amputees resulted in better 6-month survival. Health care systems must plan appropriate interdisciplinary treatment strategies for both medical and functional issues after amputation.