A reexamination of risk factors for XXXX .

@entity748 @entity1712 @entity73 @entity565 @entity3885 @entity1503 @entity402 @entity1030 @entity9416
Previous cross-sectional analyses of data from the Tucson Epidemiological Study of Airways @entity3885 have shown significant relationships of @entity73 to a variety of risk factors, including smoking, chronic productive cough, a history of childhood respiratory illnesses, @entity1503 , and serum @entity9416 ( @entity9416 ). In the present report, we reexamine these relationships in subjects 40 to 74 yr of age to determine the effect of excluding known @entity748 who, as a group, have markedly @entity73 . After exclusion of @entity748 , @entity402 , @entity1712 , and @entity9416 no longer appear to be significant risk factors for @entity73 , and nonasthmatic nonsmokers show almost no remaining @entity73 . In current smokers, quantitative relationships of FEV1 to pack-years of cigarette consumption and to chronic productive cough are changed little by excluding @entity748 . In nonasthmatic ex-smokers, however, age at quitting smoking adds significantly to prediction of FEV1 after accounting for pack-years. Young ex-smokers closely resemble nonsmokers, but they become increasingly similar to current smokers as their age at quitting increases. A history of respiratory trouble before 16 yr of age continues to appear to increase susceptibility to smoking effects, even after exclusion of @entity748 . But, as in previous studies, the possible bias of preferential recall of childhood illnesses by impaired subjects limits interpretations of this observation. On the other hand, present findings suggest that such factors as @entity402 , @entity1712 , and elevated serum @entity9416 may well be risk factors for persistent @entity565 , but they have no relationship to nonasthmatic forms of @entity1030 ( @entity1030 ).(ABSTRACT TRUNCATED AT 250 WORDS)
