Is obesity associated with worse patient-reported outcomes following lumbar surgery for degenerative conditions?

Abstract

To investigate whether obesity is associated with worse patient-reported outcomes following surgery for degenerative lumbar conditions. We evaluated consecutive patients undergoing elective lumbar laminectomy or laminectomy with fusion for degenerative lumbar conditions. The Oswestry Disability Index (ODI), EuroQol-5D (EQ-5D), Short-Form 12 (SF-12), and NASS patient satisfaction were utilized. Chi-square tests and student t test assessed the association of obesity with PROs. Multivariate regression controlled for age, sex, smoking status, anxiety, depression, revision, preoperative narcotic use, payer status, and diabetes. A total of 602 patients were included. All PROs improved significantly in both groups. BMI ≥35 was associated with increased ODI at baseline (50.6 vs. 47.2%, p=0.012) and 12months (30.5 vs. 25.7%, p=0.005). There was no difference in ODI change scores (21.2 vs. 19.4%, p=0.32). With multivariate analysis, BMI ≥35 was not predictive of worse ODI at 12months (correlation coefficient 1.23, 95% CI -0.225 to 2.676.) There was no significant difference between groups in percentage of patients achieving the minimum clinically important difference for ODI (59.6 vs. 64%, p=0.46) or patient satisfaction (80.5 vs. 78.9%, p=0.63). Body mass index ≥35 is associated with worse baseline and 12-month PROs, however, there was no difference in change scores across BMI groups. Controlling for important co-variables, BMI greater than 35 was not an independent predictor of worse PROs at 12months.