How Do Physical Therapists Measure Treatment Outcomes in Adults With Chronic Low Back Pain? A Systematic Review

Background There is an increasing recognition of the importance of using a conceptual framework covering the full range of relevant health domains and outcome measures addressed by physical therapy modalities in patients with chronic low back pain (CLBP). However, little is known about what outcome domains have been measured and through what measures in physical therapy research. Objective The purpose of this review was to synthesize outcome domains, instruments, and cutoff values reported in published randomized controlled trials and their compliance with the original Patient-Reported Outcomes Measurement Information System (PROMIS) framework. Data sources Embase, MEDLINE, Cochrane Library, and Physiotherapy Evidence Database electronic databases were systematically searched from January 2008 to April 2019. Study selection Randomized controlled trials that compared physical therapy with any other intervention for adults with CLBP were included. Data extraction Study characteristics, outcome domains, instruments, and cutoff values were extracted by 2 reviewers. The PROMIS framework was used for domain categorization. Data synthesis One hundred ninety-five studies were included, with 52 outcome domains and 45 cutoff values identified from 182 instruments reported. Only 14 of 195 studies assessed all PROMIS health core areas, whereas the PROMIS physical health core area was assessed in all included studies. Pain intensity and disability were the most frequently used domains. Limitations Only studies for which full texts were available in English were included. Conclusions This review identified a poor overlap between the PROMIS framework and outcome domains used to define the effectiveness of physical therapy in adults with CLBP. This finding suggests that other potential benefits resulting from physical therapy modalities are not being measured. Furthermore, a large diversity in the outcome domains and instruments was found.