Effects of Inpatient Rehabilitation in Hip and Knee Osteoarthritis: A Naturalistic Prospective Cohort Study With Intraindividual Control of Effects

Objectives: To quantify pain, function, and health-related quality of life in comparison with normative data, and to quantify intervention effects. Design: Naturalistic cohort study without a control group. Correction of the effects observed during the intervention by those observed during waiting time prior to the intervention. Setting: Inpatient rehabilitation clinic. Participants: Patients with hip (n=88) and knee (n=164) osteoarthritis. Intervention: Comprehensive, multidisciplinary inpatient rehabilitation lasting 3 weeks. Main Outcome Measures: Medical Outcomes Study 36-Item Short-Form Health Survey and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results: Four or more comorbid conditions had 45.3% of the hip and 51.8% of the knee patients on entry to and discharge from the clinic. On entry, physical health and some dimensions of psychosocial health were significantly diminished compared with population norms. At discharge, hip osteoarthritis had improved by a corrected effect size of .20 to .47 in pain, -.04 to .39 in function, and -.04 to .32 in psychosocial health. Knee osteoarthritis showed a corrected effect size of .43 to .62 in pain, .19 to .51 in function, and .19 to .30 in psychosocial health. All but 1 effect in WOMAC pain and WOMAC function were higher than the minimal clinically important differences. Conclusions: Hip and knee osteoarthritis patients admitted to the inpatient intervention were affected by a substantial burden of disease and comorbidities. Inpatient rehabilitation resulted in small to moderate, statistically significant, and clinically important improvements in pain, function, and psychosocial health. (C) 2013 by the American Congress of Rehabilitation Medicine