Department of Health Sciences, Institute of Academic and Research, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Department of Epidemiology, School of Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
BMC Womens Health. 2022 Jul 6;22(1):278. doi: 10.1186/s12905-022-01805-y.
While women's parity status and education level have independent associations with cardiovascular and other diseases, no studies have evaluated the additive interaction of these two factors. Therefore, we examined the additive interaction between parity and education level on mortality from stroke, coronary heart disease, total cardiovascular disease, cancer, non-cardiovascular disease, and non-cancer causes, and all causes in Japanese women.
This study followed 41,242 women aged 40-79 years without a history of cardiovascular disease or cancer from 1988 to 1990 until 2009. Baseline parity and education level were classified into four categories, with highly educated parous women as the reference group. Cox proportional hazards regression analyses were performed to calculate the risk of mortality. We also assessed the additive interactions between parity and education level on mortality from cardiovascular disease and other causes using the relative excess risk due to interaction obtained using Cox models.
During the median follow-up period of 19.1 years, we identified 6299 deaths. In a multivariable model adjusted for cardiovascular disease and other disease risk factors, nulliparous women with low education levels had increased multivariable-adjusted hazard ratios of 1.67 (95% confidence interval [CI] 1.13, 2.47) for stroke, 1.98 (95% CI 1.15, 3.39) for coronary heart disease, 1.71 (95% CI 1.34,2.18) for total cardiovascular disease, 1.69 (95% CI 1.33, 2.14) for non-cardiovascular and non-cancer, and 1.51 (95% CI 1.30, 1.75) for all-cause mortality when compared with highly educated parous women. Moreover, we observed significant additive interactions between parity and education level on total cardiovascular disease mortality (P = 0.04), non-cardiovascular disease and non-cancer mortality (P = 0.01), and all-cause mortality (P = 0.005).
Nulliparity and low education levels are super-additively associated with total cardiovascular disease, non-cardiovascular and non-cancer, and all-cause mortality risks, suggesting that nulliparous women with low education levels need specific support for preventing mortality related to cardiovascular and other diseases.
虽然女性的平等地位和教育水平与心血管疾病和其他疾病有独立的关联，但尚无研究评估这两个因素的相加交互作用。因此，我们研究了日本女性生育状况和教育水平对中风、冠心病、心血管疾病总死亡率、癌症、非心血管疾病和非癌症死因以及所有死因的相加交互作用。
本研究纳入了 1988 年至 1990 年期间无心血管疾病或癌症史、年龄在 40-79 岁之间的 41242 名女性，随访至 2009 年。根据生育状况和教育水平将基线分为四类，以高学历多产妇为参照组。采用 Cox 比例风险回归分析计算死亡率风险。我们还通过 Cox 模型获得的交互作用超额相对风险来评估生育状况和教育水平对心血管疾病和其他原因死亡率的相加交互作用。
在中位随访期 19.1 年期间，我们共确定了 6299 例死亡。在调整了心血管疾病和其他疾病危险因素的多变量模型中，低教育水平的未产妇发生中风的多变量校正风险比为 1.67（95%置信区间 [CI] 1.13，2.47），冠心病为 1.98（95% CI 1.15，3.39），心血管疾病总死亡率为 1.71（95% CI 1.34，2.18），非心血管和非癌症死亡率为 1.69（95% CI 1.33，2.14），全因死亡率为 1.51（95% CI 1.30，1.75），与高学历多产妇相比。此外，我们还观察到生育状况和教育水平对心血管疾病总死亡率（P=0.04）、非心血管和非癌症死亡率（P=0.01）和全因死亡率（P=0.005）的相加交互作用具有统计学意义。
未生育和低教育水平与心血管疾病总死亡率、非心血管和非癌症死亡率以及全因死亡率呈超相加关系，提示低教育水平的未产妇需要特别支持，以预防与心血管和其他疾病相关的死亡。
