Study design: Retrospective cohort study.
Objective: To (1) confirm validity of Patient-Reported Outcomes Measurement Information System (PROMIS) physical function and pain interference computer-adaptive tests (CATs) and (2) assess the validity of PROMIS Global Health (GH) and five additional PROMIS CATs: social role satisfaction, fatigue, anxiety, depression, and sleep disturbance in a population of patients with chronic low back pain (cLBP) who completed a 3-month Interdisciplinary Pain Program (IPP).
Summary of background data: Recent recommendations for assessing outcomes in patients with cLBP have included PROMIS scales; however, there is a need for further evaluation, and PROMIS GH has not been studied in this population.
Methods: The study cohort included patients with cLBP who completed the entirety of a 3-month IPP between August 2016 and December 2018. Patient-reported outcome measures (PROMs) were analyzed before the start of the IPP and at graduation. Convergent and discriminant validity were evaluated using Pearson correlation coefficients. Known groups' validity assessed the change in PROMIS scores stratified by improvement on the Modified LBP Disability Questionnaire. Responsiveness was evaluated with standardized response means based on global impression of change.
Results: IPP was completed by 217 patients (67.7% women, age 53.8 ± 12.8). Convergent validity was supported (P < 0.01 for all pairwise PROMs comparisons). All PROMs improved significantly by graduation, with the largest improvement for PROMIS pain interference, physical function, social role satisfaction, and Modified LBP Disability Questionnaire. Known groups' validity demonstrated the greatest change on PROMIS physical function, social role satisfaction, pain interference, and depression. Responsiveness was supported for all PROMs in 170 (78.3%) patients who indicated at least minimal improvement (standardized response means 0.43-1.06).
Conclusion: Our study provides support of PROMIS CATs, highlights the importance of including other meaningful outcome measures, such as social role satisfaction, and provides the first validation of PROMIS GH, in patients with cLBP. PROMs collection can be streamlined through the use of PROMIS CATs which offer advantages over legacy measures.
Level of evidence: 3.