Physician visits: volume and interval since last visit, United States, 1980.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D010820:Physicians / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D014481:United States