Effect of Obesity on Inpatient Rehabilitation Outcomes after Total Hip Arthroplasty

Authors

  • Heather K. Vincent,

    1. Department of Orthopedics and Rehabilitation, University of Florida, Gainesville, Florida
    2. Physical Medicine and Rehabilitation, University of Virginia Health System, Charlottesville, Virginia.
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  • Jenpin P. Weng,

    1. Physical Medicine and Rehabilitation, University of Virginia Health System, Charlottesville, Virginia.
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  • Kevin R. Vincent

    Corresponding author
    1. Physical Medicine and Rehabilitation, University of Virginia Health System, Charlottesville, Virginia.
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Department of Orthopedics and Rehabilitation, UF&Shands Orthopaedics and Sports Medicine Institute, P.O. Box 112727, University of Florida, Gainesville, FL 32611. E-mail: hkvincent@comcast.net

Abstract

Objective: This study examined whether obesity affected inpatient rehabilitation outcomes after total hip arthroplasty (THA).

Research Methods and Procedures: This was a retrospective, comparative study conducted using a computerized medical database derived from THA patients at a university-affiliated rehabilitation hospital (data from 2002 to 2005). Patients were divided into four brackets based on BMI: non-obese (<25 kg/m2), overweight (25 to 29.9 kg/m2), moderate obesity (30 to 39.9 kg/m2), and severe obesity (≥40 kg/m2). All patients completed an interdisciplinary inpatient rehabilitation program after THA. Functional independence measure (FIM) scores, length of stay (LOS), FIM efficiency scores (FIM/LOS), hospital charges, and discharge disposition location were collected.

Results: FIM scores improved from admission to discharge similarly in all groups (25 to 29.5 points). However, FIM efficiency, LOS, and total charges were curvilinearly related with BMI (all p < 0.05). Total hospital charges were highest in the severely obese group compared with the overweight group (p < 0.05). Non-homebound discharge disposition rates were lower in non-obese (13.1%) and severely obese groups (10.5%).

Discussion: Elevated BMI does not prevent FIM gains in THA patients during inpatient rehabilitation. However, BMI is related with FIM efficiency, LOS, and hospital charges in a curvilinear fashion. Severely obese patients can achieve physical improvements but at a lower efficiency and greater cost.

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