Wiborg Øyvind Nicolay, Gugushvili Alexi
Department of Sociology and Human Geography, University of Oslo, Norway.
DIW-Berlin, Germany.
SSM Popul Health. 2025 Apr 21;30:101805. doi: 10.1016/j.ssmph.2025.101805. eCollection 2025 Jun.
This study examines the association between partnership status and mortality, addressing methodological concerns such as selection effects and unobserved heterogeneity. Utilizing Norwegian administrative data on birth cohorts from 1955 to 1975, we analyze mortality outcomes using Kaplan-Meier survival analyses and Cox proportional hazards regression models. The dataset includes over 1.2 million individuals and distinguishes between partnered and non-partnered individuals. While results for the general population show that non-partnered individuals face significantly higher mortality risks, with hazard ratios of 1.59 for men and 1.47 for women, twin fixed effects models reveal no significant relationship between partnership status and mortality. This finding suggests that much of the observed association may be due to shared genetic and environmental factors rather than a direct causal effect of partnership status. By leveraging the twin fixed effects research design, this study provides a robust test of the partnership-mortality hypothesis, highlighting the importance of controlling for unobserved heterogeneity in observational research. Our results underscore the complexity of the partnership-health nexus and call for caution in interpreting simple associations as evidence of causality.
本研究考察了伴侣关系状态与死亡率之间的关联，探讨了诸如选择效应和未观察到的异质性等方法学问题。利用挪威1955年至1975年出生队列的行政数据，我们使用Kaplan-Meier生存分析和Cox比例风险回归模型分析死亡率结果。该数据集包含超过120万人，并区分了有伴侣和无伴侣的个体。虽然总体人群的结果显示，无伴侣个体面临的死亡风险显著更高，男性的风险比为1.59，女性为1.47，但双胞胎固定效应模型显示伴侣关系状态与死亡率之间没有显著关系。这一发现表明，观察到的大部分关联可能是由于共享的遗传和环境因素，而不是伴侣关系状态的直接因果效应。通过利用双胞胎固定效应研究设计，本研究对伴侣关系-死亡率假说进行了有力检验，突出了在观察性研究中控制未观察到的异质性的重要性。我们的结果强调了伴侣关系与健康关系的复杂性，并呼吁在将简单关联解释为因果关系证据时保持谨慎。
