Nguyen Thu T, Tchetgen Tchetgen Eric J, Kawachi Ichiro, Gilman Stephen E, Walter Stefan, Glymour M Maria
Department of Epidemiology & Biostatistics, University of California, San Francisco, 550 16th Street, San Francisco, CA 94158, United States.
Department of Biostatistics, Harvard T.H. Chan School of Public Health, 677 Huntington Ave, Boston, MA 02215, United States.
SSM Popul Health. 2017 Dec;3:586-593. doi: 10.1016/j.ssmph.2017.07.002.
There is a consistent association between education and depressive symptoms, but research on the mechanisms to explain this association remains limited. No study has formally evaluated the extent to which the association between education and depressive symptoms is mediated through a foundational skill such as literacy. Inverse odds ratio weighting (IORW) was used to estimate total, natural direct, and natural indirect effects in examining literacy as a mediator of the association between education and depressive symptoms. Health and Retirement Study participants born in the U.S. between 1900 and 1947 were interviewed biennially for up to 12 years (N = 16,718). Literacy was assessed with a brief vocabulary measure. Depressive symptoms were measured using the 8-item Centers for Epidemiologic Studies-Depression (CES-D) scale. Decomposition estimates were derived using regression analyses of repeated measures of depressive symptoms. Standard errors were obtained using a nonparametric bootstrap with the individual as the independent unit to account for dependence of observations within an individual. In a large cohort of older Americans, a one standard deviation difference in educational attainment (~ 3 years) was associated with a 0.35-point decrement in CES-D score (95% CI: -0.38, -0.32). This decrement represents a 0.22 standard deviation difference in depressive symptoms. Using IORW, the estimated effect of education on depressive symptoms mediated through literacy was -0.10 (95% CI: -0.18, -0.01), which represents 28% of the total effect. Education confers many benefits; as demonstrated by this study for depressive symptoms, one important benefit is literacy.
教育与抑郁症状之间存在持续的关联，但关于解释这种关联的机制的研究仍然有限。没有研究正式评估教育与抑郁症状之间的关联在多大程度上是通过诸如读写能力这样的基础技能来介导的。在检验读写能力作为教育与抑郁症状之间关联的中介因素时，采用逆概率比加权法（IORW）来估计总效应、自然直接效应和自然间接效应。对1900年至1947年在美国出生的健康与退休研究参与者进行了为期12年的每两年一次的访谈（N = 16,718）。用一个简短的词汇量测量方法来评估读写能力。使用8项流行病学研究中心抑郁量表（CES-D）来测量抑郁症状。通过对抑郁症状重复测量的回归分析得出分解估计值。使用以个体为独立单位的非参数自助法获得标准误，以考虑个体内部观察值的依赖性。在一大群美国老年人中，教育程度相差一个标准差（约3年）与CES-D得分下降0.35分相关（95%置信区间：-0.38，-0.32）。这种下降代表抑郁症状相差0.22个标准差。使用IORW，通过读写能力介导的教育对抑郁症状的估计效应为-0.10（95%置信区间：-0.18，-0.01），占总效应的28%。教育带来许多益处；正如本研究对抑郁症状所表明的，一个重要益处就是读写能力。
