Correlates of longitudinal use of complementary and alternative medicine among people with osteoarthritis: findings from the osteoarthritis initiative

Abstract

Purpose: Although correlates of complementary and alternative medicine (CAM) have been described using cross-sectional study designs, data describing use patterns over time are sparse. The purpose of this study was to describe correlates of CAM usage patterns among persons with radiographically confirmed knee osteoarthritis (OA). Methods:We included 2,114 participants of the Osteoarthritis Initiative with radiographic tibiofemoral knee OA in at least one knee at baseline who had five assessments completed over 4 years. Trained interviewers asked “During the past 6 months, did you use the following health supplements for joint pain or arthritis?” with separate questions for chondroitin sulfate and glucosamine (GLU/CHON). Participants also reported use of provider based CAM (e.g. acupuncture, ayurveda, naturopathy, biofeedback, homeopathy, Reiki, chiropractic, message) and patient self-directed CAM therapies (e.g. biologically-based supplements (SAME, MSM, vitamins, herbs), biologically-based diets, biologically-based topical agents, magnet therapy, mind-body interventions (Tai Chi, Yoga, Chi Gong, or Pilates, relaxation, spiritual activities)). Correlates of treatment approach for OA considered included sociodemographic indicators, body mass index, overall measures of mental and physical well-being, and clinical indices of knee OA. Polytomous logistic regression provided adjusted odds ratio estimates (aOR) and 95% confidence intervals (CI). Results: Fifty-five percent reported no use of GLU/CHON at any of the five assessments, 18.6% reported use at one or two times, 13.4% at three or four times, and 12.8% at all assessments. Relative to non-Hispanic Whites, Blacks had reduced odds of reports of GLU/CHON use on multiple assessments (aOR use 1-2 times: 0.59; (95% CI: 0.41-0.86); aOR use 3-4 times: 0.38; (95% CI: 0.23-0.61); aOR use 5 times: 0.13; (95% CI: 0.06- 0.28)). Those with greater than college graduate education relative to those with