Table_1_Education level as a predictor of the onset of health problems among China’s middle-aged population: Cox regression analysis.docx

BackgroundDespite the importance of midlife with reference to one’s health, educational inequalities in midlife health have attracted little attention in China. Using Cox proportional hazards regression analysis, this study examined the association between educational attainment and the onset of midlife health problems and investigated the potential mediating effects of socioeconomic position (SEP) other than educational attainment, depression, and health behavior.MethodsData were extracted from the China Health and Retirement Longitudinal Survey (CHALRS) from 2011 (baseline) to 2018 (latest data). Participants aged 45–59 years at baseline were studied (N = 8,050). Health outcomes included the onset of poor self-rated health (SRH), limitation in activities of daily living (ADL) and instrumental ADL (IADL), multimorbidity, hypertension, dyslipidemia, heart diseases, and stroke over the 7-year follow-up period. Cox proportional hazard models were used to examine the associations of the outcomes with educational attainment, while controlling for potential mediators (other SEP, depression, and health behaviors).ResultsLower educational level was associated with increased incidences of poor SRH and ADL/IADL limitations, but with decreased incidences of dyslipidemia and heart disease. After adjusting for baseline covariates, the RII was 2.17 (95% confidence interval [CI]: 1.74, 2.70) for poor SRH, 2.15 (95% CI: 1.42, 3.26) for ADL limitation, 3.84 (95% CI: 2.98, 4.94) for IADL limitation, 0.52 (95% CI: 0.40, 0.68) for dyslipidemia, and 0.55 (95% CI: 0.40, 0.74) for heart disease. Significant proportions (2.1 to 27.0%) of the RII were explained by the mediators. No sex or urban–rural differences were found in this study.ConclusionOur findings suggest that educational attainment is an important predictor of the incidences of key midlife health problems, with significant mediating effects exerted by other indicators of SEP, depression, and health behavior.

尽管中年阶段与健康的关系至关重要，但在中国，中年健康教育不平等问题却鲜受关注。本研究采用Cox比例风险回归分析，探讨了教育水平与中年健康问题发生之间的关联，并调查了除教育水平之外的社会经济地位（SEP）、抑郁情绪和健康行为等因素的潜在中介作用。

研究方法：数据来源于2011年（基线）至2018年（最新数据）的《中国健康与养老追踪调查》（CHALRS）。研究对象为基线时年龄在45至59岁之间的参与者（N=8,050）。研究期间的健康结果包括不良自我评价健康（SRH）、日常生活活动（ADL）和工具性日常生活活动（IADL）限制、多病共存、高血压、血脂异常、心脏病和卒中。通过Cox比例风险模型考察了健康结果与教育水平之间的关联，同时在模型中控制了潜在的调节因素（其他SEP、抑郁情绪和健康行为）。

研究结果：教育水平较低与不良SRH和ADL/IADL限制的发病率增加相关，但与血脂异常和心脏病发病率降低相关。调整基线协变量后，不良SRH的相对风险指数（RII）为2.17（95%置信区间[CI]：1.74，2.70），ADL限制为2.15（95% CI：1.42，3.26），IADL限制为3.84（95% CI：2.98，4.94），血脂异常为0.52（95% CI：0.40，0.68），心脏病为0.55（95% CI：0.40，0.74）。RII中显著比例（2.1%至27.0%）可由调节因素解释。本研究未发现性别或城乡差异。

结论：我们的研究结果表明，教育水平是中年健康问题发生的重要预测指标，其他SEP、抑郁情绪和健康行为的指标在中介作用中发挥了显著影响。