Correlates of Gait Speed in Advanced Knee Osteoarthritis

Objective. This study aims to evaluate correlates of gait speed, a measure of disability, in older adults with advanced knee osteoarthritis (OA) and chronic pain. Design/Setting/Subjects/Methods. Baseline data were analyzed from a clinical trial of 190 participants aged >50 with advanced knee OA (according to clinical and radiographic American College of Rheumatology criteria) and chronic pain. Data included 4-meter gait speed, quality of life (Short Form Health Survey 36 global health subscale), knee pain (Western Ontario and McMasters Universities Osteoarthritis Index [WOMAC]), depressive symptoms (Center for Epidemiologic Studies Depression Scale), coping strategies (catastrophizing subscale and Cognitive Strategies Questionnaire), self-efficacy (Athritis Self-efficacy Scale [ASES]), comorbidity (Cumulative Illness Rating Scale), analgesic use, and pain comorbidities (location, frequency, and intensity). A multivariable regression model was used to investigate these variables as they relate to gait speed. Results. In the univariate analysis, the following variables were associated with gait speed: knee pain (per WOMAC), age, depressive symptoms, global health, catastrophizing, ASES function and other, comorbidity, and opioid use (all P values <0.05). In the fully adjusted multivariate model, controlling for knee pain, significant associations between gait speed and age (beta = -0.006; P < 0.001), ASES function (beta = 0.003; P < 0.001), and opioid use (beta = -0.082; P = 0.009) persisted. The correlation between opioid dose and gait speed (among opioid users) was not statistically significant (r = 0.04; P = 0.81). Conclusion. In a cross-sectional study of older adults with advanced knee OA and chronic pain, we found that age, arthritis function self-efficacy, and opioid use (but not dose) were significantly associated with decreased gait speed.