Pulmonary Disease, Chronic ObstructiveLung Diseases, ObstructiveForced Expiratory VolumeSpirometryRespiratory Function TestsBronchodilator AgentsLung DiseasesDyspneaVital CapacityLungPulmonary EmphysemaScopolamine DerivativesSmokingAdministration, InhalationOxygen Inhalation TherapySputumExercise ToleranceSeverity of Illness IndexEmphysemaCholinergic AntagonistsRespiratory MusclesRespiratory System AgentsIpratropiumAlbuterolAsthmaSmokeRespiratory InsufficiencyBronchiAdrenal Cortex HormonesBronchitis, ChronicAdrenergic beta-2 Receptor AgonistsQuality of LifePulmonary MedicineTreatment OutcomeInspiratory CapacityExpectorantsPneumoniaRespiratory MucosaCase-Control StudiesRisk Factorsalpha 1-Antitrypsin DeficiencyRespiratory TherapyNebulizers and VaporizersBronchitisBronchoalveolar Lavage FluidInhalationProspective StudiesHospitalizationBronchiectasisBlood Gas AnalysisTime FactorsBreathing ExercisesExercise TestOxygenPositive-Pressure RespirationWork of BreathingChronic DiseaseRespiration, ArtificialHypercapniaBronchoscopyRespiratory MechanicsRetrospective StudiesDisease ProgressionQuestionnairesHeliumExhalationNoninvasive VentilationLung Volume MeasurementsComorbidityMetered Dose InhalersRespiratory SystemMycobacterium Infections, NontuberculousPulmonary Gas ExchangeHome Care Services, Hospital-BasedPhosphodiesterase 4 InhibitorsCross-Sectional StudiesDouble-Blind MethodPrevalenceExercise TherapyAcute DiseaseCohort StudiesAirway ResistanceBiological MarkersInflammationEthanolaminesAirway ObstructionRespiratory Tract DiseasesMycobacterium avium-intracellulare InfectionMucusTotal Lung CapacityAnti-Inflammatory AgentsCystic FibrosisGlucocorticoidsPulmonary VentilationBreath TestsRisk AssessmentCoughGlycopyrrolateDiaphragmStatistics, Nonparametric