UCSF

Characteristics of Workers with Painful Acute and Chronic Low Back Pain in an Urban Occupational Medical Center Background: In the workplace, low back problems account for nearly a third of both occupational complaints and workers' compensation (WC) claims. Most low back pain (LBP) resolves within weeks or months. A small percentage becomes chronic or recurrent. This small group accounts for the largest percentage of costs in both personal and economic terms. Due to methodological variations in the literature, no firm conclusions regarding the natural history of work-related LBP can be reached. Objectives: To describe acute LBP in workers after recent injury (< 2 weeks) and determine the proportion that persist 3 months or greater. A second objective is to examine the relationship of predictor variables-gender, age, and history of previous LBP- and the outcome variable-development of chronic occupational low back disability. Design: The descriptive correlational study incorporates secondary data and a mailed questionnaire. Methodology: A database query identified 270 workers with LBP-related medical diagnosis codes (ICD-9) at an occupational medical clinic. A mailed questionnaire assessed post-injury symptoms, work status, and job satisfaction. Measures administered were the Oswestry Low Back Disability Index, Roland-Morris Disability Questionnaire, SF-12, and the Stanford Presenteeism Scale. Results: There were 38 workers with acute LBP in the sample; 65.8% attributed LBP to recent overexertion on the job. Twenty-three (60.5%) developed CLBP and fifteen (39.5%) had acute LBP that resolved within 3 months (binomial test, P = .10 (Z = 10.04, p < .0005). Predictors associated with CLBP were pain level, SF-12 Physical, Oswestry, Roland-Morris, previous LBP, radiating LBP, and perception of supervisor review of workers' rights. Conclusions: A high proportion of workers with acute LBP developed CLBP (60.5%). Fifteen (39.5%) had acute LBP that resolved within 3 months (median 38.0 days; QD 19.0). These finding suggest that acute OLBP, even when evaluated and treated early after report of injury, persists in many injured workers. This knowledge could support future prospective study of acute OLBP and early disability risk factors that predict CLBP disability.