Patient Credit and CollectionAsthmaPopulation SurveillanceSentinel SurveillanceAnti-Asthmatic AgentsPublic Health SurveillanceAsthma, Exercise-InducedProduct Surveillance, PostmarketingDisease OutbreaksAdministration, InhalationAsthma, OccupationalImmunologic SurveillancePeak Expiratory Flow RateDisease NotificationUnited StatesForced Expiratory VolumeBronchodilator AgentsBronchial HyperreactivityRespiratory SoundsPrevalence