title: Concepts and problems in epidemiology.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001724:Birth Weight; D002648:Child; D002675:Child, Preschool; D004501:Education, Medical; D005006:Ethnicity; D005260:Female; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D008427:Maternal Health Services / Q000592:standards; D008428:Maternal Mortality; D008875:Middle Aged; D009026:Mortality; D009520:New Zealand; D009774:Obstetrics / Q000193:education; D011247:Pregnancy; D011786:Quality Control; D012923:Social Class; D006113:United Kingdom