Czeisler M, Wiley J, Czeisler C, Rajaratnam S, Howard M
Turner Institute for Brain and Mental Health, Monash University, Melbourne, Victoria, Australia.
Institute for Breathing and Sleep, Austin Health, Melbourne, Victoria, Australia.
medRxiv. 2021 Apr 6:2021.01.28.21250694. doi: 10.1101/2021.01.28.21250694.
Markedly elevated adverse mental health symptoms were widely observed early in the coronavirus disease 2019 (COVID-19) pandemic. Unlike the U.S., where cross-sectional data indicate anxiety and depression symptoms have remained elevated, such symptoms reportedly declined in the U.K., according to analysis of repeated measures from a largescale longitudinal study. However, nearly 40% of U.K. respondents (those who did not complete multiple follow-up surveys) were excluded from analysis, suggesting that survivorship bias might partially explain this discrepancy. We therefore sought to assess survivorship bias among participants in our longitudinal survey study as part of The COVID-19 Outbreak Public Evaluation (COPE) Initiative.
Survivorship bias was assessed 4,039 U.S. respondents who completed surveys including the assessment of mental health as part of The COPE Initiative in April 2020 and were invited to complete follow-up surveys. Participants completed validated screening instruments for symptoms of anxiety, depression, and insomnia. Survivorship bias was assessed for (1) demographic differences in follow-up survey participation, (2) differences in initial adverse mental health symptom prevalences adjusted for demographic factors, and (3) differences in follow-up survey participation based on mental health experiences adjusted for demographic factors.
Adjusting for demographics, individuals who completed only one or two out of four surveys had higher prevalences of anxiety and depression symptoms in April 2020 (e.g., one-survey four-survey, anxiety symptoms, adjusted prevalence ratio [aPR]: 1.30, 95% confidence interval [CI]: 1.08-1.55, =0.0045; depression symptoms, aPR: 1.43, 95% CI: 1.17-1.75, =0.00052). Moreover, individuals who experienced incident anxiety or depression symptoms had higher odds of not completing follow-up surveys (adjusted odds ratio [aOR]: 1.68, 95% CI: 1.22-2.31, =0.0015, aOR: 1.56, 95% CI: 1.15-2.12, =0.0046, respectively).
Our findings revealed significant survivorship bias among longitudinal survey respondents, indicating that restricting analytic samples to only respondents who provide repeated assessments in longitudinal survey studies could lead to overly optimistic interpretations of mental health trends over time. Cross-sectional or planned missing data designs may provide more accurate estimates of population-level adverse mental health symptom prevalences than longitudinal surveys.
在2019冠状病毒病（COVID-19）大流行早期，人们广泛观察到不良心理健康症状显著增加。与美国不同，美国的横断面数据显示焦虑和抑郁症状一直居高不下，而据一项大规模纵向研究的重复测量分析显示，英国的此类症状有所下降。然而，近40%的英国受访者（即那些未完成多次随访调查的人）被排除在分析之外，这表明生存偏差可能部分解释了这种差异。因此，作为COVID-19疫情公共评估（COPE）倡议的一部分，我们试图评估我们纵向调查研究参与者中的生存偏差。
对4039名美国受访者的生存偏差进行了评估，这些受访者完成了包括心理健康评估在内的调查，作为2020年4月COPE倡议的一部分，并被邀请完成随访调查。参与者完成了针对焦虑、抑郁和失眠症状的有效筛查工具。对以下方面进行了生存偏差评估：（1）随访调查参与情况的人口统计学差异；（2）根据人口统计学因素调整后的初始不良心理健康症状患病率差异；（3）根据人口统计学因素调整后的基于心理健康经历的随访调查参与情况差异。
在调整人口统计学因素后，在四项调查中仅完成一两项调查的个体在2020年4月的焦虑和抑郁症状患病率较高（例如，一项调查对四项调查相比，焦虑症状，调整患病率比[aPR]：1.30，95%置信区间[CI]：1.08 - 1.55，P = 0.0045；抑郁症状aPR：1.43，95%CI：1.17 - 1.75，P = 0.00052）。此外，经历过新发焦虑或抑郁症状的个体未完成随访调查的几率更高（调整优势比[aOR]分别为：1.68, 95%CI：1.22 - 2.31，P = 0.0015；aOR：1.56, 95%CI：1.15 - 2.12, P = 0.0046）。
我们的研究结果揭示了纵向调查受访者中存在显著的生存偏差，这表明在纵向调查研究中仅将分析样本限制为提供重复评估的受访者可能会导致对心理健康趋势随时间的解释过于乐观。与纵向调查相比，横断面或计划缺失数据设计可能会提供更准确的人群水平不良心理健康症状患病率估计。
