Prognosis and course of disability in patients with chronic nonspecific low back pain: a 5- and 12-month follow-up cohort study

Abstract

Background: Few data are available on the course of and predictors for disability in patients with chronic nonspecific low back pain (CNSLBP).

Objective: The purpose of this study was to describe the course of disability and identify clinically important prognostic factors of low-back-pain-specific disability in patients with CNSLBP receiving multidisciplinary therapy.

Design: A prospective cohort study was conducted.

Methods: A total of 1,760 patients with CNSLBP who received multidisciplinary therapy were evaluated for their course of disability and prognostic factors at baseline and at 2-, 5-, and 12-month follow-ups. Recovery was defined as 30% reduction in low back pain-specific disability at follow-up compared with baseline and as absolute recovery if the score on the Quebec Back Pain Disability Scale (QBPDS) was ≤20 points at follow-up. Potential prognostic factors were identified using multivariable logistic regression analysis.

Results: Mean patient-reported disability scores on the QBPDS ranged from 51.7 (SD=15.6) at baseline to 31.7 (SD=15.2), 31.1 (SD=18.2), and 29.1 (SD=20.0) at 2, 5, and 12 months, respectively. The prognostic factors identified for recovery at 5 and 12 months were younger age and high scores on disability and on the 36-Item Short-Form Health Survey (SF-36) (Physical and Mental Component Summaries) at baseline. In addition, at 5-month follow-up, a shorter duration of complaints was a positive predictor, and having no comorbidity and less pain at baseline were additional predictors at 12-month follow-up.

Limitations: Missing values at 5- and 12-month follow-ups were 11.1% and 45.2%, respectively.

Conclusion: After multidisciplinary treatment, the course of disability in patients with CNSLBP continued to decline over a 12-month period. At 5- and 12-month follow-ups, prognostic factors were identified for a clinically relevant decrease in disability scores on the QBPDS.