Of the 764 children whose parents believed that they had received some pertussis immunization, 97% had vaccinespecific data (from parental sources or record reviews) to confirm immunization. Data on one or more pertussis doses were also obtained for 96% of those children whose parents said that they had not received any pertussis vaccine, and for 95% of those whose parents were not sure.
L’échantillon de 88 sujets auquel on a eu recours pour valider les renseignements fournis par les parents ne différait pas de façon significative du reste du groupe étudié du point de vue de l’âge (moyenne + écart-type de 5,3 + 2,8 ans comparativement à 5,0 + 2,6 ans, respectivement; valeur p d’après un test bilatéral = 0,31).