Impact of low back pain chronicity on patient outcomes treated in outpatient physical therapy: a retrospective observational study

Abstract Objective To examine the potential relationship between physical therapy (PT) treatment outcomes and chronicity of low back pain (LBP) in the outpatient setting. Design Retrospective observational study Setting Outpatient physical therapy clinics across 11 states Participants 11941 patients with LBP provided physical therapy services and discharged from care between January 1, 2017 to December 31, 2018 Main Outcome Measure Focus on Therapeutic Outcome (FOTO) Low Back Functional Status (FS) Patient-Reported Outcome Measure (PROM) was the primary outcomes measure used. It assesses the patients’ perceived physical abilities for patients experiencing low back pain impairments. It determined a functional score on a linear metric ranging from 0 (low functioning) to 100 (high functioning). The difference in score between the intake FS and final FS score produced the FS change which represented the overall improvement of the episode of care. Results The mean FS change was 16.997 (n=11945). Patients with chronic symptoms (> 90 days duration) had an FS change of 15.920 (n=7264) across 14.63 visits. Patients with subacute symptoms (15-90 days) had an FS change of 21.66 (n=3631) across 14.05. Patients with acute symptoms (0-14 days) had an FS change of 29.32 (n=1050) across 13.66 visits. Stepwise regression analysis revealed a significant beta for chronicity (-4.155) with all models. Conclusions Overall, this study shows patients experiencing shorter duration of LBP symptoms prior to starting a physical therapy episode of care experience significantly better outcomes than patients who waited. Furthermore, the number of treatment session and duration of care was similar between groups, indicating potential ineffective or insufficient care was provided for patients with chronic pain.