Is there a difference between CAGE interviews and written CAGE questionnaires?

Background: The CAGE questionnaire is a frequently studied and used instrument for screening of alcohol problems. It was developed and tested as a written questionnaire, but, clinically, it is often used as an oral interview. No comparisons have been made between the results of a written and an oral CAGE. This study attempted to (1) compare the results of a written CAGE questionnaire and a CAGE interview, and (2) compare the efficiency of using a simple open-ended question about drinking habits before asking the CAGE and asking the CAGE without an introduction. Methods: All patients who attended a general internal medicine, cardiology, or hepatology clinic were classified according to the week of the consultation, as follows: group I (week 1), patients completed a written CAGE and were subsequently interviewed during a normal consultation by a physician, who also asked the CAGE questions; group II (week 2), a physician first interviewed the patients, including the CAGE, and subsequently patients completed a written CAGE; and group III (week 3), patients completed a CAGE interview after an open-ended introduction ("What do you drink during the day?"). Kappa values were used to compare the answers of the written and oral CAGE interviews (groups II and I). Nonparametric ANOVA was used to compare the results of group III and the oral interview of group II. Results: Mean age was comparable between the groups, gender ratio was comparable between groups I and III, but there were fewer males in group II. Comparison of all written CAGEs with the oral CAGEs in the same patients resulted in an accuracy of 0.91 and a kappa value of 0.75 (95% CI, 0.66-0.84). No significant difference could be found between the results of the oral CAGE with or without an open-ended introduction (p = 0.46). Conclusions: We found no difference between the oral and the written versions of the CAGE. This is important because most research results originate from written questionnaires. Our results do not support the finding that a different approach to the CAGE questions results in an increasing number of patients in which alcohol problems were detected.