Session Title: Rehabilitation Sciences
Session Type: Abstract Submissions (ARHP)
To examine the effect of obesity on inpatient rehabilitation outcomes after lower extremity arthroplasty procedures (hip and knee) among Medicare Beneficiaries aged 65 years and older.
We conducted a retrospective analysis in a cohort of 103,445 Medicare Part A Beneficiaries with osteoarthritis who underwent primary total hip arthroplasty (THA) (N=32,671) or total knee arthroplasty (TKA) (N=70,774) between 2007 and 2009. Patients were identified using a combination of International Classification of Diseases, Ninth Revision and diagnosis related groups codes for primary THA or TKA, osteoarthritis, overweight/obesity, and morbid obesity. Data for rehabilitation outcomes were obtained using the Inpatient Rehabilitation Facilities Patient-Assessment Instrument file. Patients were grouped in three categories (normal weight, overweight/obesity, and morbid obesity). Rehabilitation outcomes included: Functional status information (FIM scores at admission and discharge, and FIM score change) and length of stay (LOS).
The prevalence of overweight/obesity and morbid obesity was 11.4% vs. 4.7% among patients with THA, and 16.8% vs. 8.1% among patients with TKA. LOS was higher among morbid obesity for both THA and TKA [4.2, (Standard Deviation=2.7) vs. 4.2 (2.7)]. Mean FIM total score change was 29.4 (1.5) vs. 29.5 (12.3) for overweight/obesity and morbid obesity among those with THA, and 30.1 (11.5) vs. 31.3 (12.2) among those with TKA. Multivariable analysis for LOS controlled for age, gender, race/ethnicity, year of discharge, and discharge destination showed that LOS in morbid obesity in both THA and TKA was higher than those with normal weight or overweight/obesity (ß = 0.18, p-value 0.0037 vs. 0.20, p-value < 0.0001). Multivariable analysis for FIM total score change showed that the highest change was observed among morbid obesity with TKA (ß = 2.28, p-value < 0.0001) followed by morbid obesity with THA (ß = 0.91, p-value = 0.0018), overweight/obesity with TKA (ß = 0.89, p-value < 0.0001), and overweight/obesity with THA (ß = 0.43, p-value = 0.0236) when compared with normal weight.
Patients with overweight/obesity and morbid obesity experience functional gains during inpatient rehabilitation, with those in the morbid obesity group experiencing the greatest gains. LOS for those with morbid obesity was greater than the other groups, providing support to the Center for Medicare and Medicaid Services tier comorbidity system for inpatient rehabilitation following THA or TKA. Our results suggest that obesity has an impact on LOS and functional status gains during rehabilitation. Future research is needed to explore the tier-based comorbidity reimbursement system and examine the impact of obesity on other rehabilitation impairment groups.
S. Al Snih,
T. A. Reistetter,
J. E. Graham,
K. J. Ottenbacher,
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/obesity-and-rehabilitation-outcomes-after-lower-extremity-arthroplasty/