Understanding the untreated course of adults with chronic pain seeking psychological intervention: a systematic review and meta-analysis

The untreated course of chronic pain is not well understood, despite the importance of this information for treatment planning and benchmarking. This study examined symptom change over time and potential moderators in control groups of people seeking psychological pain management for chronic pain. After preregistration, we conducted a systematic literature search for RCTs of psychologically based treatment for chronic pain, which included a control condition whereby participants do not receive treatment (ie, waitlist control or no-treatment control). Meta-analyses were performed to determine that magnitude of symptom change across the control period for pain intensity, disability/interference, depression, and anxiety. Several potential moderators were also analysed. Data were extracted from 52 eligible studies (n = 2190), and the average control period was 13.5 weeks (range: 3-34). Overall, untreated participants demonstrated very small but statistically significant improvements in pain intensity (g = -0.07; CI: -0.13, -0.01) and disability/interference (g = -0.07; CI: -0.12, -0.01) over the control period. No significant change in depression (g = -0.06; CI: -0.11, 0.00) and anxiety (g = -0.05; CI: -0.11, 0.01) symptoms were observed. Some moderators were found. The findings suggest that people with chronic pain do not deteriorate or improve while waiting short periods of time for psychologically based pain management programs, contrary to some previous reports. Instead, the findings suggest that symptoms are relatively stable. These findings may be helpful for treatment and service planning as well as benchmarking activities concerning psychologically based pain management.