Two "yes" responses indicate that the respondent should be investigated further.
The questionnaire asks the following questions:
The CAGE questionnaire, among other methods, has been extensively validated for use in identifying alcoholism. CAGE is considered a validated screening technique, with one study determining that CAGE test scores >=2 had a sensitivity of 93% and a specificity of 76% for the identification of problem drinkers. 
It is not valid for diagnosis of other substance use disorders, although somewhat modified versions of the CAGE are frequently implemented for such a purpose.
- Paddington Alcohol Test
- AUDIT Questionnaire
- CRAFFT Screening Test
- Severity of Alcohol Dependence Questionnaire
- Ewing, John A. “Detecting Alcoholism: The CAGE Questionnaire” JAMA 252: 1905-1907, 1984
- CAGE Questionnaire (PDF)
- Kitchens JM (1994). "Does this patient have an alcohol problem?". JAMA 272 (22): 1782–7. doi:10.1001/jama.272.22.1782. PMID 7966928.
- Bernadt, MW; Mumford, J; Taylor, C; Smith, B; Murray, RM (1982). "Comparison of questionnaire and laboratory tests in the detection of excessive drinking and alcoholism". Lancet 6 (8267): 325–8. doi:10.1016/S0140-6736(82)91579-3. PMID 6120322.