Early Predictors of Lumbar Spine Surgery after Occupational Back Injury: Results from a Prospective Study of Workers in Washington State.

by Keeney BJ, Fulton-Kehoe D, Turner JA, Wickizer TM, Chan KC, Franklin GM.

 

Source

From the Department of #Orthopaedics, Geisel School of Medicine at Dartmouth College the Department of †Environmental and Occupational Health Sciences, University of Washington School of Public Health the Department of ∫Psychiatry and Behavioral Sciences, University of Washington School of Medicine the Department of ^Rehabilitation Medicine, University of Washington School of Medicine the Department of ‡Division of Health Services Management and Policy, Ohio State University College of Public Health ✧Biostatistics, University of Washington School of Public Health the Department of *Health Services, University of Washington School of Public Health ¶Washington State Department of Labor and Industries, Olympia, WA.

Abstract

Study Design. Prospective population-based cohort study.

Objective. To identify early predictors of lumbar spine surgery within 3 years after occupational back injury. 

Summary of Background Data. Back injuries are the most prevalent occupational injury in the United States. Few prospective studies have examined early predictors of spine surgery after work-related back injury. 

Methods. Using Disability Risk Identification Study Cohort (D-RISC) data, we examined the early predictors of lumbar spine surgery within 3 years among Washington State workers with new worker’s compensation temporary total disability claims for back injuries. Baseline measures included worker-reported measures obtained approximately 3 weeks after claim submission. We used medical bill data to determine whether participants underwent surgery, covered by the claim, within 3 years. Baseline predictors (P < 0.10) of surgery in bivariate analyses were included in a multivariate logistic regression model predicting lumbar spine surgery. The model’s area under the receiver operating characteristic curve (AUC) was used to determine the model’s ability to identify correctly workers who underwent surgery. 

Results. In the D-RISC sample of 1,885 workers, 174 (9.2%) had a lumbar spine surgery within 3 years. Baseline variables associated with surgery (P < 0.05) in the multivariate model included higher Roland Disability Questionnaire scores, greater injury severity, and surgeon as first provider seen for the injury. Reduced odds of surgery were observed for those under age 35, women, Hispanics, and those whose first provider was a chiropractor. 42.7% of workers who first saw a surgeon had surgery, in contrast to only 1.5% of those who saw a chiropractor. The multivariate model’s AUC was 0.93 (95% CI 0.92-0.95), indicating excellent ability to discriminate between workers who would versus would not have surgery. Conclusion. Baseline variables in multiple domains predicted lumbar spine surgery. There was a very strong association between surgery and first provider seen for the injury, even after adjustment for other important variables.