Effect of Low Back Pain Chronicity on Patient Outcomes Treated in Outpatient Physical Therapy: A Retrospective Observational Study

Arch Phys Med Rehabil. 2020 May;101(5):861-869. doi: 10.1016/j.apmr.2019.11.009. Epub 2019 Dec 23.


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 PT clinics across 11 states.

Participants: A total of 11,941 patients with LBP provided with PT services and discharged from care between January 1, 2017, and December 31, 2018.

Main outcome measures: Focus on Therapeutic Outcome 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 LBP 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=11,945). Patients with chronic symptoms (>90-d duration) had an FS change of 15.920 (n=7264) across 14.63 visits. Patients with subacute symptoms (15-90d) had an FS change of 21.66 (n=3631) across 14.05. Patients with acute symptoms (0-14d) had an FS change of 29.32 (n=1050) across 13.66 visits. Stepwise regression analysis revealed a significant â for chronicity (-4.155) with all models.

Conclusions: Overall, this study shows patients experiencing shorter duration of LBP symptoms before starting a PT 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.

Keywords: Chronic pain; Low back pain; Patient care planning; Patient outcomes assessment; Physical therapy modalities; Rehabilitation.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Acute Pain / rehabilitation
  • Ambulatory Care*
  • Chronic Pain / rehabilitation*
  • Female
  • Humans
  • Low Back Pain / rehabilitation*
  • Male
  • Middle Aged
  • Patient Reported Outcome Measures*
  • Physical Therapy Modalities*
  • Retrospective Studies
  • United States