Quality of data on parents' smoking and drinking provided by adult offspring

Evaluation of adult health risks from exposures that occurred in childhood may require case-control studies in which subjects who are now adults are asked to provide information that might be more accurately provided by their parents. The quality of parental smoking and drinking histories provided by adult offspring was evaluated in a North Carolina study of cancer risk from childhood exposure to cigarette smoke. A total of 1,036 adult subjects aged 15-59 years were asked about parents' smoking and drinking habits during the subject's childhood and prior to the subject's birth. Parents or siblings of 70% of the study subjects were also interviewed to obtain the same information. Subjects were generally able to provide information on parents' smoking habits, although they were less able to answer questions requiring knowledge of dates or amounts. Accuracy of information provided, as measured by agreement between subjects and mothers or between subjects and siblings, was also good for many simple exposure questions. Age and race influenced the proportion of subjects able to provide information but did not affect the quality of data. Case-control status and habits of parents had an effect on agreement between subjects and mothers for some questions but had no overall effect on the quality or interpretation of data. Cigar smoking and alcohol consumption were not reported as completely or accurately as cigarette smoking. Overall, this study demonstrated the feasibility of evaluating effects of some childhood exposures by obtaining exposure information from individuals who are now adults. Data from such studies can be used to distinguish exposed from nonexposed subjects but cannot readily be used to estimate level of exposure.