Background

Equity in access to scheduled surgery has been a topic of attention of researchers and decision-makers on healthcare. Most studies analyse the number of days that patients wait before undergoing surgery, and ignore patients that have been on the waiting list but have not benefited from surgery. This study contributes to the existing literature on waiting lists by analysing cancellations along with surgery episodes.

Methods

We use a database comprising all patients that entered the waiting list for scheduled surgeries in the Portuguese National Health Service from 2011 to 2015 (around 3 million observations) and estimate survival models to explain waiting times, where cancellations are introduced as censored data.

Results

The cancellation rate is significant (around 14%), and has a considerable impact on results: ignoring cancellations biases estimates, in particular for gender differences (that are overestimated without cancelations), and for the age effect (that is underestimated).

Conclusion

Thus, our approach provides a more accurate understanding of the impact that several factors have on overall access to scheduled surgery.

中文翻译：

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取消对等待时间分析的影响：来自葡萄牙 NHS 预定手术的证据

背景

获得预定手术的公平性一直是医疗保健研究人员和决策者关注的话题。大多数研究分析了患者在接受手术前等待的天数，而忽略了已在等待名单上但未从手术中受益的患者。这项研究通过分析取消和手术事件，为现有的等候名单文献做出了贡献。

方法

我们使用一个数据库，该数据库包含从 2011 年到 2015 年进入葡萄牙国家卫生服务局预定手术等待名单的所有患者（大约 300 万次观察），并估计生存模型来解释等待时间，其中将取消作为审查数据引入。

结果

取消率显着（约 14%），并且对结果有相当大的影响：忽略取消偏差估计，特别是性别差异（在没有取消的情况下被高估）和年龄效应（被低估）。

结论

因此，我们的方法可以更准确地理解几个因素对计划手术的整体访问的影响。