Smoking habits and reported illness in two communities with different systems of social support.
D000328:Adult; D000368:Aged; D003153:Community Health Services; D004194:Disease / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008824:Michigan; D008875:Middle Aged; D010414:Pennsylvania; D012306:Risk; D012907:Smoking; D012959:Socioeconomic Factors; D012962:Sociology, Medical; D013223:Statistics as Topic