We explore the effect of nursing home status on healthcare outcomes such as hospitalisation, mortality and in-hospital mortality during the COVID-19 pandemic. Some claim that in specific Autonomous Communities (geopolitical divisions) in Spain, elderly people in nursing homes had restrictions on access to hospitals and treatments, which raised a public outcry about the fairness of such measures. In this work, the case of the Basque Country is studied under a rigorous statistical approach and a physician's perspective. As fairness/unfairness is hard to model mathematically and has strong real-world implications, this work concentrates on the following simplification: establishing if the nursing home status had a direct effect on healthcare outcomes once accounted for other meaningful patients' information such as age, health status and period of the pandemic, among others. The methods followed here are a combination of established techniques as well as new proposals from the fields of causality and fair learning. The current analysis suggests that as a group, people in nursing homes were significantly less likely to be hospitalised, and considerably more likely to die, even in hospitals, compared to their non-residents counterparts during most of the pandemic. Further data collection and analysis are needed to guarantee that this is solely/mainly due to nursing home status.

翻译：本研究探讨新冠疫情期间，养老院居住状态对住院率、死亡率及院内死亡率等医疗结果的影响。有观点认为，在西班牙某些自治区（地缘政治区划）中，养老院老年人在获取医院和诊疗服务方面受到限制，此类措施引发了公众对公平性的强烈质疑。本研究通过严谨的统计学方法，结合临床医生视角，对巴斯克地区的案例进行分析。鉴于公平/不公平问题难以量化建模且具有重大现实影响，本研究聚焦于以下简化问题：在控制年龄、健康状况、疫情时期等有效患者信息后，确定养老院居住状态是否对医疗结果产生直接影响。研究方法融合了既有成熟技术与因果关系及公平学习领域的新成果。当前分析表明，与社区居住者相比，养老院居民群体在疫情大部分阶段中住院概率显著降低，而死亡（包括院内死亡）概率显著升高。需进一步开展数据采集与分析，以确认上述现象是否主要/唯一归因于养老院居住状态。