Depression, pain catastrophizing, and anxiety commonly co-occur with chronic pain. However, the degree to which improvement in these psychological comorbidities predicts subsequent pain outcomes and, in particular, the relative effects of these 3 psychological factors with respect to one another is only partially known. Longitudinal analysis of 250 primary care patients with chronic musculoskeletal pain enrolled in the Stepped Care to Optimize Pain care Effectiveness (SCOPE) trial was examined, using data gathered at baseline, 3 and 12 months. Mixed effects model repeated measures (MMRM) analyses were used to determine if changes in depression, pain catastrophizing, and anxiety predicted a subsequent reduction in pain intensity/interference and pain-related disability. Defining a clinically significant change as twice the standard error of measurement (SEM) for each predictor, a 2-SEM improvement in depression, pain catastrophizing, and anxiety resulted in, respectively, an effect size decrease in pain intensity/interference of 0.45, 0.33, and 0.12; a 14%, 12%, and 6% reduction in the number of pain-specific disability days; and a 43%, 30%, and 28% decreased likelihood of high disability (defined as ≥ 10 pain-specific disability days in the past 4 weeks).
In summary, improvements in 3 common psychological comorbidities predict better pain outcomes.