Characteristics of individuals selected for and included in the validation of the event-driven reporting in the population-based disease surveillance in Stockholm County 2008 and 2009.

aIncluded in the analysis were selected individuals who returned at least one validation questionnaire with interpretable answers. bThe “Missing” category included children who had not yet finished school, selected children n = 495, included children n = 397. cThe “Married” category included individuals in registered partnerships.