Over a median period of @ months , the long detection period was associated with a @ % reduction in the number of overall therapies ( @ versus @ per @ patient-years ; incidence rate ratio , @ ; @ % confidence interval , @-@ @ ; P = @ ) and a @ % reduction in the number of shocks ( rate per @ patient-years , @ versus @ ; incidence rate ratio , @ ; @ % confidence interval , @-@ @ ; P = @ ) .