Minimal Clinically Important Change of Movement Pain in Musculoskeletal Pain Conditions

Timothy R Fleagle; Andrew A Post; Dana L Dailey; Carol G T Vance; M Bridget Zimmerman; Emine O Bayman; Leslie J Crofford; Kathleen A Sluka; Ruth L Chimenti

doi:10.1016/j.jpain.2024.03.003

Minimal Clinically Important Change of Movement Pain in Musculoskeletal Pain Conditions

J Pain. 2024 Mar 12:S1526-5900(24)00424-3. doi: 10.1016/j.jpain.2024.03.003. Online ahead of print.

Authors

Timothy R Fleagle¹, Andrew A Post¹, Dana L Dailey², Carol G T Vance¹, M Bridget Zimmerman³, Emine O Bayman⁴, Leslie J Crofford⁵, Kathleen A Sluka¹, Ruth L Chimenti¹

Affiliations

¹ Department of Physical Therapy and Rehabilitation Sciences, University of Iowa Carver College of Medicine, Iowa City, Iowa.
² Department of Physical Therapy and Rehabilitation Sciences, University of Iowa Carver College of Medicine, Iowa City, Iowa; Department of Physical Therapy, St. Ambrose University, Davenport, Iowa.
³ Department of Biostatistics, University of Iowa Colleges of Public Health, Iowa City, Iowa.
⁴ Department of Biostatistics, University of Iowa Colleges of Public Health, Iowa City, Iowa; Department of Anesthesia, University of Iowa Carver College of Medicine, Iowa City, Iowa.
⁵ Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.

PMID: 38479557
DOI: 10.1016/j.jpain.2024.03.003

Abstract

Movement pain, which is distinct from resting pain, is frequently reported by individuals with musculoskeletal pain. There is growing interest in measuring movement pain as a primary outcome in clinical trials, but no minimally clinically important change (MCIC) has been established, limiting interpretations. We analyzed data from 315 participants who participated in previous clinical trials (65 with chronic Achilles tendinopathy; 250 with fibromyalgia) to establish an MCIC for movement pain. A composite movement pain score was defined as the average pain (Numeric Rating Scale: 0-10) during 2 clinically relevant activities. The change in movement pain was calculated as the change in movement pain from pre-intervention to post-intervention. A Global Scale (GS: 1-7) was completed after the intervention on perceived change in health status. Participants were dichotomized into non-responders (GS ≥4) and responders (GS <3). Receiver operating characteristic curves were calculated to determine threshold values and corresponding sensitivity and specificity. We used the Euclidean method to determine the optimal threshold point of the Receiver operating characteristic curve to determine the MCIC. The MCIC for raw change in movement pain was 1.1 (95% confidence interval [CI]: .9-1.6) with a sensitivity of .83 (95% CI: .75-.92) and specificity of .79 (95% CI: .72-.86). For percent change in movement pain the MCIC was 27% (95% CI: 10-44%) with a sensitivity of .79 (95% CI: .70-.88) and a specificity of .82 (95% CI: .72-.90). Establishing an MCIC for movement pain will improve interpretations in clinical practice and research. PERSPECTIVE: A minimal clinically important change (MCIC) of 1.1- points (95% CI: .9-1.6) for movement pain discriminates between responders and non-responders to rehabilitation. This MCIC provides context for interpreting the meaningfulness of improvement in pain specific to movement tasks.

Keywords: Clinical relevance; MIC; Minimal clinically important difference; Movement-evoked pain; Musculoskeletal pain.

Grants and funding

UL1 TR002537/TR/NCATS NIH HHS/United States