Occupational MedicineHealthy Worker EffectOccupational ExposureOccupational DiseasesCohort StudiesEmploymentOccupational HealthRisk FactorsFollow-Up StudiesProspective StudiesCohort EffectRetrospective StudiesIncidenceLongitudinal StudiesProportional Hazards ModelsTime FactorsTreatment OutcomeAge FactorsRisk AssessmentInfant, NewbornUnited StatesCase-Control StudiesPrevalenceQuestionnairesMultivariate AnalysisPregnancyPrognosisDenmarkRiskLogistic ModelsSex FactorsOdds RatioSwedenPredictive Value of TestsSeverity of Illness IndexGreat BritainSmokingEpidemiologic MethodsRegistriesGenotype