Socioeconomic status and use of physician services: a reconsideration.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004522:Educational Status; D005006:Ethnicity; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010820:Physicians / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D014481:United States