Prospective population-based cohort study.
To identify early predictors of lumbar spine surgery within 3 years after occupational back injury.
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.
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 workers 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 area under the receiver operating characteristic curve of the model was used to determine the model's ability to identify correctly workers who underwent surgery.
In the D-RISC sample of 1885 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-Morris Disability Questionnaire scores, greater injury severity, and surgeon as first provider seen for the injury. Reduced odds of surgery were observed for those younger than 35 years, females, Hispanics, and those whose first provider was a chiropractor. Approximately 42.7% of workers who first saw a surgeon had surgery, in contrast to only 1.5% of those who saw a chiropractor. The area under the receiver operating characteristic curve of the multivariate model was 0.93 (95% confidence interval, 0.92–0.95), indicating excellent ability to discriminate between workers who would versus would not have surgery.
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.
Among workers with compensation for temporary total disability soon after occupational back injury, 9.2% underwent lumbar spine surgery within 3 years. Baseline Roland-Morris Disability Questionnaire scores, injury severity, and type of provider first seen for the injury were significant predictors of surgery.
*Department of Orthopaedics, Geisel School of Medicine at Dartmouth College, Lebanon, NH;
†Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA; Departments of
‡Psychiatry and Behavioral Sciences and
§Rehabilitation Medicine, University of Washington School of Medicine, Seattle, WA
¶Division of Health Services Management and Policy, Ohio State University College of Public Health, Columbus; Departments of
**Health Services, University of Washington School of Public Health, Seattle
††Washington State Department of Labor and Industries, Olympia, WA.
Address correspondence and reprint requests to Benjamin J. Keeney, PhD, Department of Orthopaedics, Hinman Box 7541, Geisel School of Medicine at Dartmouth College, Dartmouth-Hitchcock Medical Center, One Medical Center Dr., Lebanon, NH 03756; E-mail: Benjamin.J.Keeney@Dartmouth.edu
Acknowledgment date: April 30, 2012. First revision date: October 9, 2012. Second revision date: November 27, 2012. Acceptance date: November 28, 2012.
The manuscript submitted does not contain information about medical devices or drugs.
Federal (CDCP/NIOSH) funds were received in support of this work via grant R01-OH04069.
Relevant financial activities outside the submitted work: grant, expert testimony.