The influence of preoperative disability in workers’ compensation patients undergoing lumbar decompression

Background

Typically, Workers’ Compensation (WC) patients present with worse disability preoperatively and may report inferior postoperative outcomes following lumbar decompression (LD) surgery. However, it remains unclear whether severe disability influences postoperative outcomes in WC patients. This study aims to evaluate the influence of Oswestry Disability Index (ODI) scores on patient-reported outcome measures (PROMs) for WC patients undergoing LD surgery.

Methods

Patients included in this study were those of WC status who underwent LD surgery and had PROM scores. Patients were split up into two cohorts depending on if their ODI scores were less than 41 or greater than or equal to 41. This study utilized various PROMs such as the Visual Analog Scale for Leg pain (VAS-L), VAS-Back pain (VAS-B), Oswestry Disability Index (ODI), Patient Health Questionnaire-9 (PHQ-9), Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), and 12-Item Veterans RAND Physical Component Summary (VR-12 PCS) scores. Outcome scores for patients were taken starting at baseline and up to two years postoperatively. Rates of minimum clinically important difference (MCID) achievement were also calculated. A linear regression was used to analyze PROMs and MCID rates of achievement.

Results

A total of 82 WC patients were stratified into the Mild Disability Cohort (ODI < 41) and the Severe Disability Cohort (ODI ≥ 41). Thirty-two patients were in the Mild Disability Group and 50 were in the Severe Disability Group. There were no statistically significant differences in the patient demographics and perioperative characteristics. At baseline, WC patients with severe disability had significantly worse VAS-L, VAS-B, PROMIS-PF, and VR-12 PCS. At six weeks and the final postoperative time point, patients in both cohorts reported comparable scores across all PROMs besides the ODI. Patients in the Severe Disability cohort continued to report significantly worse ODI scores compared to the Mild Disability cohort. However, when measuring the magnitude of improvement in PROMs from preoperatively to the final follow-up of up to two years, patients in the Severe disability group had remarkably greater improvements in the ODI compared to patients with mild disability. Lastly, MCID achievement showed greater rates for the Severe disability group throughout. Notably, VAS-L and ODI MCID achievement rates were significantly higher in the Severe Disability Cohort.

Conclusion

The findings demonstrate worse baseline disability in WC patients can result in comparable improvements in PROMs when differentiating between the milder disability group. Importantly, WC patients with ODI ≥ 41 had clinically significant improvements in VAS-L and ODI scores following LD surgery.