P137. Preliminary analysis on the influence of workers' compensation status on outcomes of anterior lumbar interbody fusion at L5-S1.

Few studies have focused on outcomes among Workers' Compensation (WC) claimants undergoing anterior lumbar interbody fusion (ALIF). To determine the influence of WC on perioperative outcomes, patient-reported outcome measures (PROMs) and attainment rates of minimal clinically important difference (MCID) among patients undergoing single-level ALIF at L5S1. Retrospective. A retrospective surgical database of an attending spine surgeon was utilized to identify patients with WC insurance undergoing single-level ALIF at L5S1. One-hundred and nine patients were included, with 82 in the non-WC and 27 in the WC cohort. PROM data for visual analog scale (VAS) back/leg, Oswestry Disability Index (ODI), 12-Item Short Form (SF-12) Physical Composite Score (PCS) and Patient Reported Outcome Measurement Information System physical function (PROMIS-PF) was obtained preoperatively and at 6-weeks, 12-weeks, 6-months, 1-year and 2-years following ALIF. Patients were divided into groups based on insurance status: WC vs non-WC (including patients with private insurance or Medicare/Medicaid). Demographic and perioperative information was evaluated between insurance groups using student's t-test for independent samples for continuous variables and chi-squared test for categorical variables. Mean PROMs were compared with student's t-test for independent samples. Comparisons of preoperative and postoperative PROM values were evaluated with paired sample t-tests. Patients who achieved an improvement in PROM score greater than or equal to established threshold values were marked as achieving MCID. WC and non-WC groups were compared in MCID attainment rates across PROMs with chi-squared analyses. A greater proportion of the non-WC cohort were Caucasian, while a significantly greater proportion of the WC cohort were African American and Hispanic (p=0.001). Significantly more patients in the WC cohort were smokers (p<0.001). Non-WC patients improved significantly from preoperative to postoperative timepoints of 6-months through 2-years for PROMIS-PF and SF-12 PCS, 6 weeks through 1 year for VAS back, 6 months/1 year for VAS leg and 12 weeks through 1-year for ODI (p≤0.048, all). WC patients improved significantly at postoperative timepoints for PROMIS-PF at 6 weeks (p=0.029), SF-12 PCS at 12 weeks (p=0.018), VAS back from 6 weeks to 6 months, and VAS leg at 6 months, only (p≤0.029, all). Mean VAS back scores were significantly greater in the WC cohort at 6 months and 1 year (p≤0.013, both), mean VAS leg scores were significantly greater in the WC cohort at 1 year (p=0.029), and mean ODI scores were significantly higher in the WC cohort at preoperative through 1 year (p≤0.040, all). With the exception of higher MCID achievement for VAS back at 12 weeks (p=0.037), no other differences in attainment rates were observed for any PROM at any time point or for the overall postoperative period. Among patients receiving ALIF, WC insurance was more prevalent among patients identifying as Hispanic and African American, along with smokers. While physical function scores were similar between groups, long-term pain and disability (throughout the entire postoperative period) were significantly higher among patients with WC. MCID achievement, however, was largely comparable for all PROMs between WC and non-WC study groups. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]