LonelinessActivities of Daily LivingGeriatric AssessmentSocial IsolationFrail ElderlyDependent AmbulationAgingMobility LimitationLongitudinal StudiesHomebound PersonsIndependent LivingProjective TechniquesInstitutionalizationCognition DisordersHealth Services for the AgedHealth StatusInterpersonal RelationsDepressionLegal GuardiansDisabled PersonsSocial SupportGeriatricsAccidental FallsCognitionDeliriumIllinoisNeuropsychological TestsChicagoQuestionnairesRisk FactorsProspective StudiesSocial PerceptionCohort StudiesDementiaDisease ProgressionFollow-Up StudiesHospitalization