CAGE questionnaire


The CAGE questionnaire, the name of which is an acronym of its four questions, is a widely used screening test for problem drinking and potential alcohol problems. The questionnaire takes less than one minute to administer, and is often used in primary care or other general settings as a quick screening tool rather than as an in-depth interview for those who have alcoholism. The CAGE questionnaire does not have a specific intended population, and is meant to find those who drink excessively and need treatment. The CAGE questionnaire is reliable and valid; however, it is not valid for diagnosis of other substance use disorders, although somewhat modified versions of the CAGE questionnaire have been frequently implemented for such a purpose.

Overview

The CAGE questionnaire asks the following questions:
  1. Have you ever felt you needed to Cut down on your drinking?
  2. Have people Annoyed you by criticizing your drinking?
  3. Have you ever felt Guilty about drinking?
  4. Have you ever felt you needed a drink first thing in the morning to steady your nerves or to get rid of a hangover?
Two "yes" responses indicate that the possibility of alcoholism should be investigated further.
The CAGE questionnaire, among other methods, has been extensively validated for use in identifying alcoholism. CAGE is considered a validated screening technique with high levels of sensitivity and specificity. It has been validated via receiver operating characteristic analysis, establishing its ability to screen for problem drinking behaviors.

History

The CAGE questionnaire was developed in 1968 at North Carolina Memorial Hospital to combat the paucity of screening measures to detect problem drinking behaviors. The original study, conducted in a general hospital population where 130 patients were randomly selected to partake in an in-depth interview, successfully isolated four questions that make up the questionnaire today due to their ability to detect the sixteen alcoholics from the rest of the patients.

Reliability

refers to whether the scores are reproducible. Not all of the different types of reliability apply to the way that the CAGE is typically used. Internal consistency is not usually reported in studies of the CAGE; nor is inter-rater reliability.
CriterionRating Explanation with references
NormsNot applicableNormative data are not gathered for screening measures of this sort
Internal consistencyNot reportedA meta-analysis of 22 studies reported the median internal consistency was
α= 0.74.
Inter-rater reliabilityNot usually reportedInter-rater reliability studies examine whether people's responses are scored the same by different raters, or whether people disclose the same information to different interviewers. These may not have been done yet with the CAGE; however, other research has shown that interviewer characteristics can change people's tendencies to disclose information about sensitive or stigmatized behaviors, such as alcohol or drug use.
Test-retest reliability Not usually reportedRetest reliability studies help measure whether things behave more as a state or trait; they are rarely done with screening measures
RepeatabilityNot reportedRepeatability studies would examine whether scores tend to shift over time; these are rarely done with screening tests

Validity

describes the evidence that an assessment tool measures what it was supposed to measure. There are many different ways of checking validity. For screening measures such as the CAGE, diagnostic accuracy and discriminative validity are probably the most useful ways of looking at validity.
CriterionRating Explanation with references
Content validityAdequateItems are face valid; not clear that they comprehensively cover all aspects of problem drinking
Construct validity GoodMultiple studies show screening and predictive value across a range of age groups and samples
Discriminative validityExcellentStudies not usually reporting AUCs, but combined sensitivity and specificity often excellent
Validity generalizationExcellentMultiple studies show screening and predictive value across a range of age groups and samples
Treatment sensitivityNot applicableCAGE not intended for use as an outcome measure
Clinical utilityGoodFree, extensive research base, brief.

*Table from , extending Hunsley & Mash, 2008; *indicates new construct or category

Limitations

The CAGE is designed as a self-report questionnaire. It is obvious to the person what the questions are about. Because talking about drinking behavior can be uncomfortable or stigmatized, people's responses may be subject to social desirability bias. The honesty and accuracy of responses may improve if the person trusts the person doing the interview or interpreting the score. Responses also may be more honest when the form is completed online, on a computer, or in other anonymous formats.

Alternatives

Some alternatives to the CAGE include: