Improved mobility success was found among veterans undergoing major lower extremity amputation secondary to peripheral vascular disease or diabetes who received rehabilitation in a comprehensive inpatient rehabilitation unit. Greatest probability of mobility success was found in younger patients with greater social support, healthy weight and without chronic obstructive pulmonary disease, according to recent study results. “Mobility Success” was defined as the return to pre-morbid level of mobility at 1 year after amputation. This definition of mobility outcome was used because of the extensive variability in pre-morbid mobility in this patient population.
“We had been working on developing a prediction model that would allow us to determine the mobility outcome of elderly dysvascular amputees at 1 year based upon specific variables that were present in the perioperative period,” Joseph M. Czerniecki MD, associate director of the VA Rehabilitation Research Center of Excellence in Limb Loss Prevention and Prosthetic Engineering and professor of rehabilitation at the University of Washington, told O&P Business News. “As all good research should do, our involvement in this study spawned the additional research question of how important is the environment of care on dysvascular amputee outcome.”
Mobility success
Between September 2005 and December 2008, participants with peripheral vascular disease or diabetes undergoing a first unilateral major amputation were screened for enrollment. Of 199 participants screened, 113 met study inclusion criteria and 72 participants were enrolled. They were assessed in-person or telephone interview presurgically and at 6 weeks, 4 months and 12 months postsurgically. Main outcome measures included the number of rehabilitation therapy visits, Locomotor Capability Index scores and mobility success.
For patients ever attending a comprehensive inpatient rehabilitation unit (CIRU), the mean number of therapy visits was significantly greater vs. patients never attending during a 12—month period, and mean total time per any rehabilitation visit was .83 hours for patients ever attending and .60 hours for patients never attending. Study results showed that 33% of patients achieved mobility success at 12 months. From premorbid to 12 months after amputation, the mean change in Locomotor Capability Index scores among patients who achieved success was 5.5 points, while the mean change in scores for patients who did not achieve success was –14.2.
In a multivariate model that controlled for amputation level, major depressive episode, alcohol score, social support, total number of rehabilitation visits and hospital site, researchers found that any patients treated in a CIRU were 17% more likely to achieve mobility success. Multivariate model also showed that achieving mobility success was associated with younger age, higher social support score, no chronic obstructive pulmonary disease and underweight to normal BMI categories. Patients were 23% less likely to achieve mobility success if they had a major depressive episode diagnosed at 4 months or who had a greater alcohol use.
“Historically, dysvascular amputees have a low likelihood of being admitted to a CIRU. It is unclear whether this is related to funding decisions made by payers or whether there has been an underlying assumption on the part of rehabilitation professionals that inpatient rehabilitation does not necessarily enhance outcome,” Czerniecki said. “In any case, the results of our study suggest that a greater proportion of patients will experience enhanced mobility outcome if treated on a CIRU, especially those with above mentioned characteristics. Therefore admission to a CIRU should be considered the preferred rehabilitation environment of care for these patients.”
Surprising results
Czerniecki said some of the study results were surprising. “The most surprising result was that there were intangible benefits of treatment on an inpatient rehabilitation unit that resulted in improved mobility, aside from the rehabilitation treatment intensity as measured by frequency and duration of rehabilitation treatment. It is unclear whether this is related to the medical management, enhanced coordination of care or possibly other factors related to the treatment milieu, he said.”
Now that Czerniecki and colleagues have completed their preliminary development of a prediction model that allows the prediction of mobility outcome in dysvascular amputees at 1 year based on patient characteristics in the peri-operative period, the researchers plan to perform a study on geographical and temporal validation of the prediction model.
Disclosure: Czerniecki has no relevant financial disclosures.
