Sex, age, and other barriers for prosthetic referral following amputation and the impact on survival.

Background: Despite advances in peripheral vascular disease treatment, lower extremity amputation continues to be necessary in a significant number of patients. Up to 80% of amputees are not referred for prosthetic fitting. The factors contributing to referral decisions have not been adequately investigated, nor has the impact of prosthetic referral on survival. We characterized differences between patients who were successfully referred to our in-house prosthetists and those who were not, and identified factors associated with prosthetic referral and predictive of survival.

Methods: This was a retrospective analysis of all patients who underwent lower extremity amputation by surgeons in our practice from January 1, 2010, to June 30, 2017. Data regarding age, sex, race, body mass index (BMI), diabetes, hypertension, hyperlipidemia, end-stage renal disease, prior coronary artery bypass graft surgery, congestive heart failure, tobacco use, American Society of Anesthesiologists (ASA) score, previous arterial procedure, chronic obstructive pulmonary disease, statin use, postoperative ambulatory status, level of amputation, stump revision, and referral for prosthesis were collected. Survival was determined from a combination of sources, including the Social Security Death Master Index, multiple genealogic registries, and internet searches. Multivariable logistic regression was used to determine risk factors associated with prosthesis referral. Multivariable Cox proportional hazard regression with time-dependent covariates was performed to assess risk factors associated with 5-year mortality.

Results: There were 293 patients included in this study. Mean age was 66 years, and mean BMI 27 kg/m. The majority of patients were male (69%), white (53%), with diabetes (65.4%) and hypertension (77.5%), and underwent below-the-knee amputation (BKA) (73%). Prosthetic referral occurred in 123 (42.0%). Overall 5-year survival was 61.7% (95% confidence interval [CI], 55.9%-68.1%) (BKA 64.7% [95% CI, 57.9%-72.3%]; above-the-knee amputation 53.8% [95% CI, 43.4%-66.6%]). On multivariate analysis, age >70 years, female sex, diabetes, ASA score 4 or 5, and current tobacco use were associated with no referral for prosthetic fitting. Patients with BMI 25 to 30, a previous arterial procedure, BKA, and history of stump revision were more likely to be referred. Factors associated with decreased survival were increasing age, higher ASA class, black race, and BMI; prosthetic referral was seen to be protective.

Conclusions: We identified multiple patient factors associated with prosthetic referral, as well as several characteristics predictive of reduced survival after amputation. Being referred for prosthetic fitting was associated with improved survival not explained by patient characteristics and comorbidities. Further research is needed to determine whether the factors identified as associated with nonreferral are markers for patient characteristics that make them clinically unsuitable for prosthetic fitting or if they are symptoms of unconscious bias or of the patient's access to care.