Jeong Wonseok
Department of Public Health Sciences, Graduate School of Public Health, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea.
BMC Public Health. 2025 Mar 27;25(1):1167. doi: 10.1186/s12889-025-22298-y.
In South Korea, around 105,000 individuals experience strokes annually, with over 26,000 deaths and the incidence rate is keep rising due to the aging population. Physical inactivity is a major global health issue, and regular exercise is known to prevent many diseases, including stroke. Yet, previous observational studies may be biased due to unobserved factors influencing exercise and stroke occurrence. Therefore, this study aims to examine an impact of regular physical activity on stroke prevention among South Korean adults using instrumental variable approach in order to avoid problems with reverse causality and other unobserved confounding factors.
Data were obtained from the 2014 and 2016 Korean Community Health Surveys of 416,032 Korean adults. Regular exercise was the main independent variable and proximity to exercise facilities is used as an instrument. The dependent variable, presence of stroke, was defined by a doctor's diagnosis. Probit regression analyses were performed to examine the associations between the independent variable and both dependent variable and an instrument. Causal effect of regular exercise on stroke prevention were estimated with the bivariate probit regressions using proximity to exercise facilities as an instrument for regular exercise.
Consistent with prior knowledge, proximity to exercise facilities positively influenced regular exercise. The results from both multivariable probit and bivariate probit models indicate that engaging in regular exercise has a strong negative effect on the incidence of stroke. The estimated effects of regular physical activity on stroke prevention range from -0.174 percentage points (ATE) to -0.154 percentage points (ATT) in the bivariate probit model.
This study makes an important contribution by providing IV estimates on the effects of conducting regular exercise on stroke prevention based on a representative sample of South Korean adults. My findings suggest that conducting regular exercise reduces the risk of stroke even after accounting for the potential reverse causality and unobserved related factors.
在韩国，每年约有10.5万人罹患中风，其中超过2.6万人死亡，且由于人口老龄化，发病率持续上升。缺乏体育锻炼是一个重大的全球健康问题，而定期锻炼已知可预防包括中风在内的多种疾病。然而，先前的观察性研究可能因影响锻炼和中风发生的未观察因素而存在偏差。因此，本研究旨在采用工具变量法，探讨定期体育活动对韩国成年人预防中风的影响，以避免反向因果关系和其他未观察到的混杂因素问题。
数据来自2014年和2016年对416,032名韩国成年人进行的韩国社区健康调查。定期锻炼是主要自变量，与锻炼设施的距离用作工具变量。因变量中风的存在由医生诊断定义。进行了Probit回归分析，以检验自变量与因变量及工具变量之间的关联。使用与锻炼设施的距离作为定期锻炼的工具变量，通过双变量Probit回归估计定期锻炼对预防中风的因果效应。
与先前的认知一致，与锻炼设施的距离对定期锻炼有积极影响。多变量Probit模型和双变量Probit模型的结果均表明，进行定期锻炼对中风发病率有很强的负面影响。在双变量Probit模型中，定期体育活动对预防中风的估计效应范围从-0.174个百分点（平均治疗效应）到-0.154个百分点（平均处理效应）。
本研究基于韩国成年人的代表性样本，提供了关于定期锻炼对预防中风影响的工具变量估计，做出了重要贡献。我的研究结果表明，即使考虑到潜在的反向因果关系和未观察到的相关因素，进行定期锻炼也能降低中风风险。
