295: Mapping Outcomes in Randomized Controlled Trials of Psychological Interventions for Chronic Pain

Topic: Clinical Science
Subtopic: Non-specific to any diagnosis, Psychology, Assessment and Measurement of Pain/Nociception

Background and Aims: Psychological interventions are strongly endorsed for chronic pain management by the National Institutes of Health, the Centers for Disease Control and Prevention, and the International Association for the Study of Pain. These recommendations are grounded in randomized controlled trials (RCTs) in which treatment efficacy is determined by selected outcome measures. Yet, it remains unclear which outcomes are prioritized in the trials informing these recommendations and whether they reflect domains most relevant to individuals living with chronic pain. We therefore systematically map outcome selection in guideline-supported trials and examine alignment with daily functioning, participation, and overall life impact.

Methods: RCTs were identified from the Cochrane review conducted by Williams et al. 2020. All primary and secondary outcomes from 78 trials evaluating face-to-face psychological interventions in adults with chronic pain were extracted. Outcomes were classified according to the clinical outcome assessment framework for chronic pain trials described by Patel et al. 2021, based on IMMPACT recommendations. Measures were grouped into core domains, including pain intensity, physical functioning, emotional functioning, participant ratings of global improvement and treatment satisfaction, symptoms and adverse events, and participant disposition, to support standardized and comprehensive evaluation of treatment effects across trials.

Results: The included trials assessed interventions for chronic pain conditions, including fibromyalgia, low back pain, and rheumatoid arthritis. In 32 trials, outcomes were not explicitly classified as primary or secondary, limiting transparency in outcome prioritization and increasing the risk of selective reporting. Across all included studies, irrespective of outcome classification, pain intensity was reported in 63% of trials, emotional functioning in 55%, and physical functioning in 43%. Patient global ratings of improvement were included in 15% of studies. Indicators of patient disposition were documented in 1% of trials, and adverse events were assessed in only one study across the full sample.

Conclusions: Trials underpinning guideline recommendations predominantly prioritize pain intensity outcomes, with less consistent inclusion of physical and emotional functioning domains. Minimal attention is given to global patient appraisal, safety outcomes, or trial conduct indicators. Because primary endpoints shape statistical emphasis and evidence synthesis, this distribution may disproportionately highlight symptom reduction while underrepresenting broader dimensions of recovery, including participation, daily functioning, and tolerability. Greater alignment with established multidimensional outcome recommendations for chronic pain trials is needed to ensure that future studies capture clinically meaningful change and that guideline recommendations are informed by outcomes most relevant to individuals living with chronic pain.

References: Patel, K. V., Amtmann, D., Jensen, M. P., Smith, S. M., Veasley, C., & Turk, D. C. (2021). Clinical outcome assessment in clinical trials of chronic pain treatments. Pain reports, 6(1), e784.

de C Williams, A. C., Fisher, E., Hearn, L., & Eccleston, C. (2020). Psychological therapies for the management of chronic pain (excluding headache) in adults. Cochrane database of systematic reviews, (8).

Smith, S. M., Dworkin, R. H., Turk, D. C., McDermott, M. P., Eccleston, C., Farrar, J. T., ... & Wilson, H. D. (2020). Interpretation of chronic pain clinical trial outcomes: IMMPACT recommended considerations. Pain, 161(11), 2446-2461.

Turk, D. C., & Dworkin, R. H. (2004). What should be the core outcomes in chronic pain clinical trials?. Arthritis Res Ther, 6(4), 151.

Fillingim, R. B., Loeser, J. D., Baron, R., & Edwards, R. R. (2016). Assessment of chronic pain: domains, methods, and mechanisms. The journal of pain, 17(9), T10-T20.

Presenting Author: Raluca Georgescu
Submitting Author: Georgescu Raluca

Senior Author: Mark Jensen

IASP 2026 Global Year theme of Neuropathic Pain: No

• Mark Jensen: PHD - University of Washington
• Ioana Alina Cristea: PHD - University of Padova