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

Abstract

<h3>BACKGROUND CONTEXT</h3> Few studies have focused on outcomes among Workers' Compensation (WC) claimants undergoing anterior lumbar interbody fusion (ALIF). <h3>PURPOSE</h3> 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. <h3>STUDY DESIGN/SETTING</h3> Retrospective. <h3>PATIENT SAMPLE</h3> 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. <h3>OUTCOME MEASURES</h3> 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. <h3>METHODS</h3> 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. <h3>RESULTS</h3> 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. <h3>CONCLUSIONS</h3> 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. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.