A Case Crossover Analysis of Out-of-Hospital Cardiac Arrest and Particulate Matter Air Pollution: Investigation of Specific Subgroups

There is increasing evidence of association between particulate matter air pollution and cardiovascular mortality and morbidity. However, the association with the out-of-hospital cardiac arrest (OHCA) event is less clear. We investigated the effects of short-term particulate matter exposure on OHCA especially among specific subgroups. The study included OHCA that occurred in the Nord-Pas-de-Calais region, France, in 2015. A time-stratified case-crossover study design coupled with a conditional logistic regression was used to evaluate the association between OHCA and particle levels of 10 or 2.5 micrometers or less (PM10 or PM2.5 respectively) measured within the hour of the arrest up to 5 days before. Susceptible subgroups by sex, age, diabetes status among OHCA that occurred during non-holiday periods were investigated. In all, 1039 cases were included. Significant associations were found between OHCA during non-holiday periods and PM2.5 and PM10 exposure four days before the arrest and on the day of the arrest. The largest OR were found for the cumulative average twelve hours before the arrest of PM2.5 (OR = 1.17, p = 0.016) and PM10 (OR = 1.33, p < 0.001). With PM2.5, larger OR with smaller p-values were generally obtained within the subgroups of men, age 50 to 75 years old and cases with diabetes. The findings show a significant link between short-term exposure to particulate matter and OHCA during non-holiday periods, with susceptible subgroups to PM2.5 (men, age 50 to 75 years old and diabetics).