Abstract
BACKGROUND: The relationship between surgeon volume and outcomes in spine surgery is unclear and published studies report inconsistent results. Therefore, a dose-response meta-analysis was conducted to clarify the influence of surgeon volume on outcomes in spine surgery. METHODS: PubMed, Embase, and The Cochrane Library were systematically searched without language limitation for observational studies which investigated the relationship between surgeon volume and outcomes in spine surgery. The primary outcome was postoperative morbidity and the secondary outcomes consisted of mortality, length of hospital stay, readmission, and hospital costs. For binary variable and continuous variable, odds ratios (ORs) with 95% CIs and weighted mean differences (WMDs) with 95% CIs were pooled respectively. Additionally, a dose-response meta-analysis was performed for the primary outcome. RESULTS: Eleven studies with 1,986,545 patients were included in the current meta-analysis. Pooled estimate indicated that a higher surgeon volume was associated with lower postoperative morbidity (OR, 0.62; 95% CI: 0.52-0.75; I(2)=93.9%), lower mortality (OR, 0.76; 95% CI: 0.66-0.87; I(2)=0), shorter length of hospital stay (WMD, -7.07; 95% CI: -7.08 to -7.06; I(2)=100%), less readmission (OR, 0.78; 95% CI: 0.72-0.85; I(2)=93.1%), and lower hospital costs (WMD, -25,497.47; 95% CI: -25,528.43 to -25,466.51; I(2)=100%). Dose-response analysis suggested a nonlinear relationship between surgeon volume and postoperative morbidity (P for nonlinearity less than 0.00001). CONCLUSIONS: The current evidence indicate that higher surgeon volume is associated with lower morbidity and mortality, shorter length of hospital stay, less readmission, and lower hospital costs in spine surgery.