The impact of hospital and surgeon volume on clinical outcome following bariatric surgery.

The dramatic rise in the prevalence of obesity worldwide has led to the rapid growth of bariatric surgery. The aim of this pooled analysis is to evaluate the relationship between institutional and surgeon volume and outcomes following bariatric surgery. Medical, Embase, trial registries, conference proceedings and reference lists were searched for trials comparing clinical outcome following bariatric surgery at high and low volume hospitals and by high and low volume surgeons. Outcomes analysed were mortality, morbidity and length of hospital stay. Fifteen publications were included in this analysis. In total, 289,732 bariatric procedures were included in the institutional volume analysis, and 32,920 bariatric operations were included in the surgeon volume analysis. Mortality was reduced following surgery at high volume institutions (0.24 vs. 2.18 %; pooled odds ratio = 0.26; P = 0.004) and by high volume surgeons (0.41 vs. 2.77 %; pooled odds ratio = 0.21; P < 0.001). Similarly, morbidity was reduced in high volume institutions (7.84 vs. 8.85 %; pooled odds ratio = 0.52; P < 0.001) and with high volume surgeons (6.92 vs. 7.29 %; pooled odds ratio = 0.47; P < 0.001). There were insufficient data for conclusive statistical analysis of length of hospital stay. This pooled analysis does suggest a benefit in the centralisation of bariatric surgery to high volume institutions and surgeons with respect to mortality and morbidity. Future high-powered studies with adjustment for procedural and patient case mix are required to further define the volume-outcome relationship in bariatric surgery.