BrazilNational Institutes of Health (U.S.)United StatesNational Health ProgramsPrevalenceNational Library of Medicine (U.S.)National Cancer Institute (U.S.)Cross-Sectional StudiesNational Center for Health Statistics (U.S.)Risk FactorsHealth SurveysPopulation DensitySeasonsInfant, NewbornNational Heart, Lung, and Blood Institute (U.S.)Population SurveillanceNutrition SurveysData CollectionQuestionnairesRiversIncidenceAge FactorsGreat BritainUrban PopulationRegistriesTreesNational Academy of Sciences (U.S.)Sex FactorsPsychodidaeHealth Care SurveysRetrospective StudiesHealth PolicyEpidemiologic MethodsCohort StudiesTime FactorsInsect VectorsNational Institute for Occupational Safety and Health (U.S.)Indians, South AmericanLogistic ModelsDatabases, FactualEndemic DiseasesState MedicineHealth Services AccessibilityPregnancySocioeconomic FactorsEducational StatusPublic SectorGovernment AgenciesTreatment OutcomeDemographyEnvironmental MonitoringPractice Guidelines as TopicBertholletiaPopulation DynamicsSeroepidemiologic StudiesPublic HealthProspective StudiesIncomeCanadaRisk AssessmentProgram EvaluationGeographyHospitalizationEcosystemInternational CooperationRural PopulationDisease OutbreaksResearchHIV InfectionsEnglandResearch Support as TopicGenotypeFinancing, GovernmentCitiesEthnic GroupsAcademies and InstitutesMass ScreeningMultivariate AnalysisInterviews as TopicHistory, 20th CenturyDisease NotificationPhylogenySimuliidaeBiomedical ResearchDelivery of Health CareSmokingFollow-Up StudiesFresh WaterCause of DeathHealth Knowledge, Attitudes, PracticeOdds RatioPovertyGuideline AdherencePhysician's Practice PatternsFishesDeveloping CountriesEuropean Continental Ancestry Group