Longitudinal outcome evaluations of Interdisciplinary Multimodal Pain Treatment programs for patients with chronic musculoskeletal pain : a living systematic review

Background and aims: Chronic pain management requires complex approaches due to its multidimensional nature. Interdisciplinary Multimodal Pain Treatment (IMPT) programs are recommended for chronic primary pain, prioritizing improved functioning and quality of life rather than merely reducing pain. This living systematic review (LSR) builds upon prior systematic review findings, aiming to (1) assess long-term effects of IMPT on both chronic primary and secondary musculoskeletal pain, adding health-related quality of life as an outcome, (2) refine IMPT by analysing variations in treatment approaches, and (3) evaluate the value of the LSR approach in chronic pain research. Methods: A comprehensive search was conducted in four databases. Two independent researchers performed study selection, data extraction, and methodological quality assessment. Eligible articles enrolled patients with chronic primary or secondary musculoskeletal pain and evaluated longitudinal IMPT effects. Analyses included pre-post, post-follow-up, and pre-follow-up effects across ten outcome domains. Patient and intervention characteristics were systematically detailed to investigate treatment heterogeneity. Results: Eighty-nine studies met eligibility criteria, comprising 110 cohorts. A general positive improvement was observed from pre- to post-treatment across all outcome categories, with benefits largely sustained at follow-up. High heterogeneity was evident due to variations in IMPT programs, participant characteristics, and outcome measures. Conclusions: IMPT programs improve outcomes such as physical function and health-related quality of life. However, specific recommendations to optimize IMPT could not be established due to substantial heterogeneity in program dose and content. The LSR approach shows promise in chronic pain research, offering a timely method to bridge research and clinical practice.