Infants with hypoplastic left heart syndrome require an initial Norwood operation, followed some months later by a stage 2 palliation (S2P). The timing of S2P is critical for the operation's success and the infant's survival, but the optimal timing, if one exists, is unknown. In the SVRT, the timing of the S2P was chosen by the medical team; thus with respect to this exposure, the trial constitutes an observational study, and the analysis must adjust for potential confounding. To accomplish this, we propose an extended propensity score analysis that describes the time to surgery as a function of confounders in a discrete competing-risk model. Our analysis suggests that S2P conducted at 6 months after the Norwood gives the patient the best post-S2P survival. This article is protected by copyright. All rights reserved.

中文翻译：

---

从观察数据估计手术的最佳时机

患有左心发育不良综合征的婴儿需要进行初始 Norwood 手术，几个月后进行 2 期姑息治疗 (S2P)。S2P 的时机对于手术的成功和婴儿的存活至关重要，但最佳时机（如果存在）尚不清楚。在SVRT中，S2P的时机由医疗团队选择；因此，对于这种暴露，试验构成了一项观察性研究，分析必须针对潜在的混杂因素进行调整。为了实现这一点，我们提出了一种扩展的倾向评分分析，该分析将手术时间描述为离散竞争风险模型中混杂因素的函数。我们的分析表明，在 Norwood 术后 6 个月进行 S2P 可为患者提供最佳的 S2P 后存活率。本文受版权保护。版权所有。