Responsiveness and Minimal Important Change for Pain and Disability Outcome Measures in Pregnancy-Related Low Back and Pelvic Girdle Pain

Ogollah, Reuben; Bishop, Annette; Lewis, Martyn; Grotle, Margreth; Foster, Nadine E

Abstract

Background
Pregnancy-related low back pain and pelvic girdle pain (LBP/PGP) are common and negatively impact the lives of many pregnant women. Several patient-based outcome instruments measure treatment effect but there is no consensus about which measure to use with women who have these pain presentations.

Objective
The objective was to compare the responsiveness of 3 outcome measures in LBP/PGP: Oswestry Disability Index-version 2.0 (ODI), Pelvic Girdle Questionnaire (PGQ), and 0–10 numerical rating scale for pain severity (NRS); and to estimate a minimal important change (MIC) for these measures in pregnancy-related LBP/PGP.

Design
This was a methodology study using data from a pilot randomised trial (RCT).

Methods
Women (n = 124) with pregnancy-related LBP/PGP were recruited to a pilot RCT evaluating the benefit of adding acupuncture to standard care and 90 completed 8-weeks follow-up. Responsiveness was evaluated by examining correlation between change score and the external anchor (6-point global perceived effect scale) and by using receiver operating characteristic (ROC) curve analysis. MIC was estimated using anchor-based methods.

Results
All measures showed good responsiveness, with areas under ROC curve ranging from 0.77 to 0.90. The estimated MICs were 3.1, 11.0, 9.4, 13.3, and 1.3 for ODI, PGQ-total, PGQ-activity, PGQ-symptoms, and NRS, respectively. All the measures, apart from ODI, had MICs larger than the measurement error.

Limitations
Lack of optimal “gold standard” or external criterion for assessing responsiveness and MIC was a limitation of this study.

Conclusion
All 3 outcome measures demonstrated good responsiveness. MICs were derived for each instrument. The PGQ at 8 weeks post-randomisation was identified as an appropriate outcome measure for pregnancy-related LBP/PGP since it is specific to these pain presentations and assesses both activity limitations and symptoms. The NRS is an efficient, shorter alternative.

Citation

Ogollah, R., Bishop, A., Lewis, M., Grotle, M., & Foster, N. E. (2019). Responsiveness and Minimal Important Change for Pain and Disability Outcome Measures in Pregnancy-Related Low Back and Pelvic Girdle Pain. Physical Therapy, 99(11), 1551-1561. https://doi.org/10.1093/ptj/pzz107

• Journal Article Type: Article
• Acceptance Date: Jul 30, 2019
• Online Publication Date: Aug 8, 2019
• Publication Date: 2019-11
• Deposit Date: Aug 15, 2019
• Publicly Available Date: Aug 9, 2020
• Journal: Physical Therapy
• Print ISSN: 0031-9023
• Electronic ISSN: 1538-6724
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 99
• Issue: 11
• Pages: 1551-1561
• DOI: https://doi.org/10.1093/ptj/pzz107
• Keywords: Physical Therapy, Sports Therapy and Rehabilitation
• Public URL: https://nottingham-repository.worktribe.com/output/2434405
• Publisher URL: https://academic.oup.com/ptj/article-abstract/99/11/1551/5544636?redirectedFrom=fulltext
• Additional Information: This is a pre-copyedited, author-produced version of an article accepted for publication in Physical Therapy following peer review. The version of record Reuben Ogollah, Annette Bishop, Martyn Lewis, Margreth Grotle, Nadine E Foster, Responsiveness and Minimal Important Change for Pain and Disability Outcome Measures in Pregnancy-Related Low Back and Pelvic Girdle Pain, Physical Therapy, Volume 99, Issue 11, November 2019, Pages 1551–1561, is available online at: https://doi.org/10.1093/ptj/pzz107