Chronic illness in childhood. I. Epidemiological and clinicl characteristics.
D000293:Adolescent; D001847:Bone Diseases / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002648:Child; D002908:Chronic Disease / Q000453:epidemiology*; D000013:Congenital Abnormalities / Q000453:epidemiology; D006801:Humans