We examined the association between SPM and EAD for acute illness at different lag structures, including both single day lags (from lag 0 to lag 3) and cumulative lags (the cumulative exposure over the current day and the previous day, lag 0–1). Similar effects were observed for the single day lag 0 and cumulative day lag 0–1. Therefore, we reported the estimated effects of the cumulative lag 0–1 in the results to compare our effect estimates with those from previous studies about EAD data
and air pollution (Michikawa et al., 2015a; Sajani et al., 2014).