Longitudinal use of complementary and alternative medicine among older adults with radiographic knee osteoarthritis

Osteoarthritis (OA), a chronic and often painful disease for which there is no cure, accounts for more mobility issues in older adults than any other disease. Cross-sectional studies have found that arthritis is the most common reason for older adults to use complementary and alternative medicine (CAM). Although previous research has profiled the sociodemographic and clinical characteristics of CAM users, few studies have provided information on variation in CAM use over time and most only considered use of any CAM, which was often a mixture of heterogeneous therapies.

This study sought to describe the longitudinal patterns of CAM use among older adults with knee OA and to identify correlates and predictors of different commonly used CAM therapies.

The Osteoarthritis Initiative included 1121 adults aged ≥65 years with radiographic tibiofemoral OA in one or both knees at baseline. Annual surveys captured current use of conventional therapies and 25 CAM modalities (grouped into 6 categories) for joint pain or arthritis at baseline and during the 4-year follow-up. We assessed longitudinal use of CAM modalities by summing the number of visits with participants reporting use of each modality. Correlates of CAM use under consideration included sociodemographic indicators, body mass index, overall measures of mental and physical well-being, and clinical indices of knee OA. Generalized estimation equations provided adjusted odds ratio estimates and 95% CIs.

Nearly one-third of older adults reported using ≥1 CAM modality for treating OA at all assessments. With the exception of glucosamine and chondroitin (18%), few were persistent users of other CAM modalities. One in 5 of those using nonsteroidal anti-inflammatory drugs or glucosamine and/or chondroitin were using them concurrently. Adjusted models revealed the following: (1) adults aged ≥75 years were less likely to use dietary supplements than those between ages 65 and 75 years; (2) persons with more severe knee pain or stiffness reported more CAM use; (3) better knee-related physical function was correlated with more use of chiropractic care or massage; and (4) older adults with more comorbidities were less likely to report use of dietary supplements.

Patterns of CAM use are, to some extent, inconsistent with current guidelines for OA treatment. Evaluating the potential risks and benefits in older adults from commonly used CAM modalities, with or without combination use of conventional analgesics, is warranted.