Beyond time-series counts: reframing the short-term association between exposure to air pollution and mortality using the novel repeated acute exposure (RAE) design

. While numerically analogous to the Relative Risk (RR), the HR specifically reflects the instantaneous risk profile. The estimated effect size was consistent in direction and significance of the association with the one obtained using a Generalised Additive Model (GAM)-based distributed lag non-linear model (RR: 1.035; 95% CI: 1.005-1.066), and other time-series methods. The RAE design offers a rigorous sensitivity tool for validating associations through methodological triangulation. The dataset and R script for reproducibility are available on Zenodo at https://doi.org/10.5281/zenodo.19115821.