Longitudinal analysis of short-term bronchiolitis air pollution association using semiparametric models

The first aim of this work is to clearly present a very popular semi-parametric methodology often used to estimate the association between death or hospital counting data and pollution data and to estimate short-term effects of ambient air pollution on infant bronchiolitis hospital consultations. Infant bronchiolitis is a frequent infectious disease caused by a virus, the syncethial respiratory virus (RSV). Normally, contact with this virus is responsible for a cold, but in infant and in some circumstances, especially at the beginning of winter, the virus can be responsible for a severe respiratory disease which can lead to numerous hospital consultations and hospitalizations. A critical comparison of its practical application using S-Plus, R, or SAS Proc Gam is performed. It appears that more work is needed to get a satisfactory implementation of the Schwartz method in SAS with similar results to those in S-Plus or R.