Department of Pediatrics, Duke University School of Medicine, Duke Clinical Research Institute, Durham, North Carolina 27715, USA.
Ann Thorac Surg. 2012 May;93(5):1556-62. doi: 10.1016/j.athoracsur.2011.07.081. Epub 2011 Oct 19.
Norwood outcomes vary across centers, and a relationship between center volume and outcome has been previously described. It is unclear whether this volume-outcome relationship exists across all levels of patient risk or holds true for all centers. We evaluated the impact of patient risk status on the relationship between center volume and outcome, and the extent to which differences in center volume account for between-center variation in outcome.
Infants in The Society of Thoracic Surgeons Congenital Heart Surgery Database undergoing the Norwood operation (2000 to 2009) were included. Mortality associated with annual Norwood volume overall and across patient preoperative risk tertiles was evaluated in multivariable analysis. We also estimated the proportion of between-center variation in mortality explained by center volume.
The cohort included 2,557 infants from 53 centers: 34 centers with 0 to 10 Norwood cases per year; 13 centers with 11 to 20 cases per year; and 6 centers with more than 20 cases per year. Unadjusted in-hospital mortality was 22%. In multivariable analysis, lower center volume was associated with higher mortality (odds ratio in low-volume versus high-volume centers 1.54, 95% confidence interval: 1.02 to 2.32, p=0.04). The volume-outcome relationship did not differ across preoperative risk tertiles (p=0.7). Norwood volume explained an estimated 14% of the between-center variation in mortality observed, and significant between-center variation in mortality remained after adjusting for volume (p<0.001).
Center volume is modestly associated with outcome after the Norwood operation independent of patient risk status. However, this relationship explains only a portion of the between-center variation in mortality in this cohort.
诺伍德手术的结果因中心而异，之前已经描述过中心数量与结果之间的关系。目前尚不清楚这种数量-结果关系是否存在于所有患者风险水平，或者是否适用于所有中心。我们评估了患者风险状况对中心数量与结果之间关系的影响，以及中心数量差异在多大程度上解释了结果的中心间差异。
纳入了在胸外科医师学会先天性心脏病外科学数据库中接受诺伍德手术（2000 年至 2009 年）的婴儿。在多变量分析中评估了每年诺伍德手术量与患者术前风险三分位数相关的死亡率。我们还估计了中心数量解释死亡率中心间差异的比例。
该队列包括来自 53 个中心的 2557 名婴儿：34 个中心每年有 0 至 10 例诺伍德手术；13 个中心每年有 11 至 20 例手术；6 个中心每年有超过 20 例手术。未调整的院内死亡率为 22%。在多变量分析中，较低的中心数量与较高的死亡率相关（低容量中心与高容量中心的比值比为 1.54，95%置信区间：1.02 至 2.32，p=0.04）。术前风险三分位数不同，数量-结果关系也不同（p=0.7）。诺伍德手术量解释了观察到的死亡率中心间差异的估计 14%，调整手术量后仍存在显著的死亡率中心间差异（p<0.001）。
独立于患者风险状况，中心数量与诺伍德手术后的结果适度相关。然而，这种关系仅解释了该队列中死亡率中心间差异的一部分。
