Lim Hyungryul, Choi Jonghyuk, Bae Sanghyuk, Choi Kyung-Hwa, Han Xue, Ha Mina, Kim Jong-Hun, Kim Soontae, Kwon Ho-Jang
Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Republic of Korea.
Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Republic of Korea.
Int J Epidemiol. 2024 Dec 16;54(1). doi: 10.1093/ije/dyaf001.
This study assesses the national distribution of ambient fine particulate matter (PM2.5) exposure across socioeconomic status (SES) and its confounding on long-term PM2.5 mortality in Korea, aiming to minimize SES influence.
A nationwide cohort of 5% of Koreans, aged 30 or older, from 2007 to 2019, from the National Health Information Database, was analysed. PM2.5 exposure levels were estimated at the city level using the Community Multiscale Air Quality system. Mortality data were obtained from Statistics Korea. The study examined annual PM2.5 exposure by SES indicators and its confounding on mortality risks associated with PM2.5, using time-varying Cox proportional hazards models.
The study followed 1 453 036 individuals from 2007 to 2019, totalling 17 760 227 person-years (PYs). The non-accidental (A00-R99), cardiovascular (I00-I99) and respiratory (J00-J99) mortality rates per 1000 PY were 7.6, 1.9 and 0.8, respectively. We observed a trend of decreasing PM2.5 exposure levels but increased mortality among medical aid beneficiaries, those with lower household incomes and those residing in neighbourhoods with a higher area deprivation index. When adjusting for these SES covariates, the long-term mortality effects of PM2.5 shifted in the direction of increased risk [hazard ratio (HR) for cardiovascular mortality in the unadjusted model = 0.968 (95% CI: 0.909-0.959); HR in the fully adjusted model = 1.053 (95% CI: 1.004-1.105)].
In regions where SES and PM2.5 concentrations are positively correlated, as in Korea, it is crucial to rigorously control for SES confounding to avoid underestimating the mortality effects associated with PM2.5.
本研究评估了韩国环境细颗粒物（PM2.5）暴露在社会经济地位（SES）方面的全国分布情况及其对长期PM2.5死亡率的混杂影响，旨在尽量减少SES的影响。
对2007年至2019年来自国家健康信息数据库的5%年龄在30岁及以上的韩国人组成的全国性队列进行了分析。使用社区多尺度空气质量系统在城市层面估计PM2.5暴露水平。死亡率数据来自韩国统计局。该研究使用时变Cox比例风险模型，按SES指标检查了年度PM2.5暴露情况及其对与PM2.5相关的死亡风险的混杂影响。
该研究在2007年至2019年期间跟踪了1453036人，总计17760227人年（PYs）。每1000人年的非意外（A00-R99）、心血管（I00-I99）和呼吸（J00-J99）死亡率分别为7.6、1.9和0.8。我们观察到PM2.5暴露水平呈下降趋势，但医疗救助受益人、家庭收入较低者以及居住在地区贫困指数较高社区的人群的死亡率有所上升。在对这些SES协变量进行调整后，PM2.5的长期死亡影响朝着风险增加的方向转变[未调整模型中心血管死亡率的风险比（HR）=0.968（95%CI：0.909-0.959）；完全调整模型中的HR=1.053（95%CI：1.004-1.105）]。
在像韩国这样SES与PM2.5浓度呈正相关的地区，严格控制SES混杂因素以避免低估与PM2.5相关的死亡影响至关重要。
