RELIABILITY OF SMOKING HISTORY IN MEDICAL CHARTS IN RELATION TO INTERVIEW DATA

We previously reported on a series of studies exploring relationships between cigarette smoking and mutations of tumor suppressor genes; the studies relying on medical charts for data on smoking. To assess the accuracy of these data we compared them with data obtained using a con ventional epidemiologic interview. As part of an ongoing case-control study of tobacco-related cancers, a trained interviewer questioned 144 patients about their smoking habits using a structured interview inst rument; the medical charts were then reviewed. Using the Spearman test to compare the data obtained from the two sources, the correlation co efficient was 0.85 for cigarettes per day; 0.88 for years of smoking a nd 0.95 for pack-years, suggesting that the data in the charts were re liable. The kappa coefficient was 0.96 for current smoking status, ind icating a very strong agreement between the two sources of data. The s ensitivity and specificity for chart review were 96.3% and 100% respec tively, compared with the 'gold standard' of a structured interview. T hese results show that when patients cannot be interviewed, for exampl e when performing retrospective studies using existing collections of archived tumors or other biologic materials, then data on smoking abst racted from medical charts may be a reliable substitute.