Clinical depression is a strong predictor of poor lumbar fusion outcomes among workers' compensation subjects.

STUDY

DESIGN

Retrospective cohort study.

OBJECTIVE

Determine how psychosocial factors, particularly depression, impact lumbar fusion outcomes in a workers' compensation (WC) setting.

SUMMARY OF BACKGROUND DATA: WC patients are less likely to return to work (RTW) after fusion. Few studies evaluate risk factors within this clinically distinct population.

METHODS

A total of 2799 Ohio WC subjects were identified who underwent lumbar fusion between 1993 and 2013 using Current Procedural Terminology (CPT) procedural and International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes. A total of 123 subjects were diagnosed with depression before fusion. Subjects with a smoking history, prior lumbar surgery, permanent disability, and failed back syndrome were excluded. The primary outcome was whether subjects returned to work within 2 years of fusion and sustained this RTW for more than 6 months of the following year. To determine the impact depression had on RTW status, we performed a multivariate logistic regression analysis. We also compared time absent from work and other secondary outcomes using χ2 and t tests.

RESULTS

Subjects with preoperative depression had significantly higher rates of legal representation, degenerative lumbar disease, and higher medical costs, and used opioid analgesics for considerably longer before and after fusion (P<0.001).Depression group (10.6% [13/123]) and controls (33.0% [884/2676]) met our RTW criteria (P<0.001). Preoperative depression was a negative predictor of RTW status (P<0.001; odds ratio [OR]: 0.38). Additional predictors included working during same week as fusion (OR: 2.15), age more than 50 years (OR: 0.58), chronic preoperative opioid analgesia (OR: 0.58), and legal representation (OR: 0.64). After surgery, depression subjects were absent from work 184 more days compared with controls (P<0.001).

CONCLUSION

Overall, RTW rates after fusion were low, which was especially true for those with pre-existing depression. Depression was a strong negative predictor of postoperative RTW status. Psychological screening and treatment may be beneficial in these subjects. The poor outcomes in this study may highlight a more limited role for fusion among WC subjects with chronic low back pain where RTW is the treatment goal.

LEVEL OF EVIDENCE: 3.