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

Purpose To investigate whether obesity is associated with worse patient-reported outcomes following surgery for degenerative lumbar conditions. Methods 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. Results 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 12 months (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 12 months (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). Conclusions 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 12 months.