Variations in mortality from influenza and pneumonia by socioeconomic level.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000401:mortality*; D012737:Sex Factors; D012959:Socioeconomic Factors; D014481:United States