Lung Diseases, ObstructivePulmonary Heart DiseasePulmonary Disease, Chronic ObstructiveSpirometryOxygen Inhalation TherapyForced Expiratory VolumeRespiratory Function TestsAirway ObstructionTerbutalineAsthmaBronchitisIpratropiumBronchodilator AgentsVital CapacityAdministration, InhalationAlbuterolPeak Expiratory Flow RateLungBronchiAdrenal Cortex HormonesTheophyllineAerosolsSmokingSputumSleep Apnea, ObstructiveSeverity of Illness IndexAirway RemodelingOxygenAirway ResistanceRespiratory Tract DiseasesPrevalenceDouble-Blind MethodChronic DiseaseEnglandNebulizers and VaporizersBronchial HyperreactivityRespiratory SystemRespiratory MucosaPulmonary EmphysemaDyspneaRisk FactorsRetrospective StudiesRespiratory HypersensitivityJaundice, Obstructive