Minimum important change values for pain and disability: which is the best to identify a meaningful response in patients with chronic nonspecific low back pain?

• Published in: Physiotherapy theory and practice Vol. 38; no. 10; pp. 1 - 1507
• Main Authors: Pires, Diogo, Cruz, Eduardo, Canhão, Helena, Nunes, Carla
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Ltd 03-10-2022
• Subjects: Back pain; Chronic back pain; Chronic low back pain; Cohort analysis; Disability; Discrimination; Physical therapy; Physiotherapy; Sociodemographics; Values; pain measurement; disability evaluation; Low back pain; patient outcome assessment
• ISSN: 0959-3985; 1532-5040
• DOI: 10.1080/09593985.2020.1843210

To examine the association between different minimum important change (MIC) values for pain and disability and a successful response in global perception of improvement in patients with chronic nonspecific low back pain (CNLBP).
A prospective cohort study was conducted. At baseline, all participants completed a sociodemographic and clinical questionnaire, the Numeric Pain Rating Scale and the Quebec Back Pain Disability Scale (QBPDS). After a physiotherapy program, the Global Perceived Effect Scale (GPES) was completed together with pain and disability measures. The association of the different literature MIC values for pain and disability with a successful response on the GPES was analyzed using logistic regression models. The discrimination power, sensitivity, specificity and predictive values were computed.
A total of 183 patients with CNLBP participated in this study. A reduction of 30% on the QBPDS (OR = 7.8; area under the curve = 0.73; sensitivity = 0.72; specificity = 0.76) most accurately identified patients who perceived a global improvement on the GPES. Composite criteria using both pain and disability MIC values presented high odds ratios and specificity values, but failed to identify patients who perceived a meaningful improvement.
A 30% reduction on the QBPDS is recommended to identify patients with CNLBP who achieve a clinical improvement with physiotherapy treatment.