Data Management And Sharing System of China National Clinical Research Center for Neurological Diseases

Journal：International Journal of Stroke

Publication type: Original Contributions

IF(IF): 6.948

PMID: https://doi.org/10.1177/17474930221110024 Link To Pubmed Full text Download

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We estimated the association between short-term exposure to PM2.5 and the incidence of stroke using a case-crossover design. This method was developed to study the effects of transient, short-term exposures on the risk of acute events.25 In the case-crossover design, the study population consists of subjects who have experienced an episode of the health outcome of interest. An important feature of the case-crossover design is that each subject serves as his or her own control. Self-matching results are free from confounding by risk factors that are stable over time within an individual but often differ between study subjects. In our study, case days were defined as AIS diagnosis data. Ambient PM exposure on the case day was compared with exposure on matched control days. For each case, we matched three referent periods, namely, 7, 14, and 21 days before the case day, to control for potential confounding effects by day of the week.