COMPARISON OF THE CAGE QUESTIONNAIRE VERSUS SOME BIOCHEMICAL MARKERS IN THE DIAGNOSIS OF ALCOHOLISM

We have compared the individual sensitivity, specificity and predictiv e value of the CAGE questionnaire, plasma levels of ethanol and acetat e, mean corpuscular volume (MCV), gamma glutamyl transferase (GGT), an d glycosylated haemoglobin (Hb A1c) in a group of 50 healthy non-alcoh olic controls and 31 patients with non-alcoholic liver disease (Group I), and in a second group of 40 alcoholic patients (Group II). Taken i ndividually, the CAGE questionnaire was the most efficient (96% sensit ive and 92% specific), followed by plasma levels of acetate (74% sensi tive and 85% specific), MCV (64% sensitive and 91% specific) and GGT ( 72% sensitive and 80% specific). Hb A1c did not show any statistically significant difference between alcoholics and non-alcoholics and thus is of no use as a screening test for the diagnosis of alcoholism. Fur thermore, we attempted to design a discrimination procedure to separat e alcoholics from controls and patients with non-alcoholic hepatic dis eases using a combination of the most promising tests. The most powerf ul discrimination model was constructed with the four questions of the CAGE questionnaire. The percentage of correct classifications using t his model was 99% from Group I (specificity) and 90% from Group II (se nsitivity). The CAGE questionnaire was itself so useful as a discrimin ant in our sample that no increased diagnostic efficacy was noticed on adding any of the other tests. Using objective variables (MCV, acetat e and GGT) as discriminants, we could correctly classify 96% of subjec ts from Group I (specificity) and only 64% from Group II (sensitivity) .