Knee osteoarthritis (OA) pain and disability are driven by multiple biopsychosocial mechanisms, and symptoms progression varies widely across individuals. In a community-dwelling sample of middle-aged and older adults, we examined the extent to which psychological, biobehavioral, and demographic characteristics, and radiographic severity predicted pain and disability progression over a two-year period. We hypothesized that 1) psychological (e.g., depression, optimism), 2) biobehavioral (e.g., BMI, pain sensitivity), and 3) demographic (e.g., race, sex) characteristics would be uniquely associated with pain and disability progression, independent of radiographic disease severity (KL score).

Adults with chronic knee pain (n=127, 63% female) completed measures at baseline and two-year follow-up. Backwards stepwise multiple linear regression was used with criteria set to 0.05 for entry and 0.10 for removal. Change scores (e.g., TP2 - baseline) were adjusted for baseline values. Continuous predictors (e.g., depression, optimism) were centered, and categorical variables (e.g., race, sex, study site, and KL score) were dummy coded, prior to entry. Level of significance was set at p<0.05.

Clinical pain progression was associated with psychological (optimism, p=0.004), pain sensitivity (punctate pain, p<0.001), and BMI, p=0.037. Findings were similar for pain-related disability. KL score was associated with increased pain related-disability only (KL=4, p=0.010). Age, sex, income, and race were not significant. This study provides support for the impact of psychological and biobehavioral factors on pain progression in persons with knee OA, independent of radiographic joint degeneration, and suggests targeting these variables may lead to improved patient outcomes in knee OA. R37AG033906 (RBF); R01AG067757 & R01AG076082 (YCA) NIH/NIA: R37AG033906 (RBF); NIH/NIA: R01AG067757 & R01AG076082 (YCA).