Excessive alcohol consumption is a significant health risk, causing 4% of all deaths globally. However, it is difficult to effectively assess alcohol consumption and its interactions with other disorders and conditions.
Alcohol consumption is accepted to be an important topic to be questioned during medical appointments and when compiling a medical history, and questionnaires such as the Alcohol Use Disorders Identification Test (AUDIT)   are often used to aid early detection of alcohol-related issues.
It is important for healthcare professionals to utilise all of the tools necessary to identify issues with alcohol consumption to avoid problems such as over-investigation or inappropriate treatment, and to give the best possible treatment.
There are a number of rationales for enquiring about alcohol abuse:
There are three main areas that should be investigated while carrying out an enquiry on alcohol consumption. These are:
When assessing alcohol intake, there are a number of questions that should be asked. The type, concentration, and amount of alcohol typically consumed per week, and the number of days a week that drinking occurs, need to be determined.
It is also important to identify the duration of consumption and the last occasion that alcohol was consumed prior to the assessment. 
When assessing alcohol dependence, the driving force of the urge to drink needs to be identified. It must be assessed whether the patient in question has impaired control over their alcohol consumption, or feels an urge to drink alcohol in general or after a certain period of not drinking.
Dependence can also be determined by increased tolerance, withdrawal symptoms, or continued consumption of alcohol despite it causing harm to the patient’s physical and mental wellbeing.
After the alcohol intake and dependence are assessed, questions are then asked about the problems or harmful consequences of alcohol consumption. This includes questions concerning physical, mental, and social wellbeing.
Potential physical consequences are:
Potential mental and neuropsychiatric consequences are:
Examples of social harm include:
The AUDIT (Alcohol Use Disorders Identification Test) is a widely used screening instrument for detecting issues in alcohol consumption, It is a simple set of 10 questions concerning frequency and volume of consumption, feelings surrounding alcohol consumption, and frequency of experiencing certain physical, mental, or social side effects. 
This questionnaire can be handed to patients on arrival for their assessment or can be read out by the healthcare professional during the consultation.
When being used for diagnosing alcohol dependency, the AUDIT provides a score that will fit into one of three ranges: the non-hazardous range, the hazardous or harmful range, and the alcohol-dependent range.
The hazardous or harmful range will require feedback and brief intervention, and the alcohol-dependent range will require feedback, referral to a specialist, the potential need for detoxification, and the potential need for pharmacotherapy.
Although the primary purpose of the AUDIT is to screen for alcohol dependence, it can also be used to provide information on how to further interview and treat the patient.
The AUDIT can score each section separately – questions 1 to 3 can be used to indicate hazardous alcohol consumption, questions 4 to 6 assess the issue of alcohol dependence, and questions 7 to 10 assess the presence of alcohol-related issues.
If a score is particularly high in one of these areas, further questions can be asked and support can be tailored to the area that is most critical.
For the purposes of early screening and detection, questions 1 to 3 are sufficient to establish whether there is an issue with potential alcohol dependence. This shortened version of the AUDIT is called the AUDIT-C.
This test is usually used to screen for alcohol dependence in emergency departments or other acute care settings, as it takes less time to administer than the AUDIT, and is shown to be comparable in terms of quality of information obtained. 
The CAGE test is a questionnaire with four main questions :
These questions may be answered affirmatively by someone who suffers from alcohol dependency, especially the first and second questions.
These tests are important tools for early identification of alcohol dependency disorders. Early detection can help to reduce the impact of more extreme alcohol consumption before the patient starts to suffer from irreversible damage.
Clinical trials have demonstrated that as little as 4 to 5 minutes of advice on how to reduce alcohol intake can help to reduce the harmful effects of alcohol dependency for patients. This is due to the fact that the tests can pinpoint where the patient experiences the most issues and tailored advice can be given accordingly.
The tests can also be produced electronically for the purposes of self-assessment, increasing the accessibility of alcohol-related advice.
Alcohol use enquiries are generally accepted as part of medical health check-ups and history, but for some patients, alcohol consumption questions can be considered sensitive and they could respond defensively or in a hostile manner.
Those carrying out these questionnaires should show empathy whilst asking questions, and phrase queries in a softer sense if necessary. It is important that if required, the legitimacy of the enquiry is justified, for example, by explaining and emphasising how alcohol consumption can be the cause of other physical and mental health disorders.
Diversional or evasive responses may indicate that the person being questioned about alcohol consumption has a higher intake and wants to conceal this from healthcare professionals.
There are some specialised questionnaires available to use when specific aspects of alcohol consumption-related disorders need to be assessed, or more detailed information is needed in certain areas.
There are two main groups of questionnaires that are suitable for these purposes:
Physical and mental examinations may also be undertaken, as physical and mental health issues can arise from alcohol dependence.
Patients with alcohol dependence-related disorders may have some abnormalities in the results of common laboratory tests. The biological markers of alcohol alert medical professionals to the presence of alcohol-related disorders where they may not have been suspected or identified.
Laboratory tests are also valuable as they provide an objective measure of exposure to alcohol, and can assist in the monitoring of the responses of patients to treatments.
However, it is important to note that biological markers for alcohol are not necessarily the most reliable indicators of alcohol consumption-related conditions, generally only detecting 50-60% of patients with alcohol-related disorders at best – and this statistic may be as low as 20-30% in the broader clinical population.
The most reliable biomarker for alcohol is CDT (carbohydrate-deficient transferrin). This marker has a sensitivity level of 50-70% and can identify alcohol dependency-related disorders with a specificity of 95%. 
There are, however, a few other causes of abnormally high CDT levels, such as pregnancy and some forms of liver disease. Nevertheless, CDT is one of the most promising biological markers for alcohol dependency identification.
Blood alcohol concentration is another measure that can be used to identify issues in alcohol dependency and consumption.  This test crucially depends on the time that the patient in question last drank alcohol.
Blood alcohol concentration reduces due to the body’s metabolism, so the more time that passes, the less the blood alcohol concentration will be, regardless of the patient’s true alcohol intake.
Detecting the presence of alcohol intake-related disorders requires the same skillset that is needed for other areas of clinical practice. The relevant questions should be asked in an empathic, non-judgemental way, and assessments should be undertaken with the utmost respect for the patient.
Screening questionnaires are useful for both the detection of alcohol dependency-related issues and for determining what the best support and help is for the patient.
Physical examinations and biological markers can also be used to provide additional context for healthcare professionals, helping them to successfully tailor treatment to each individual patient.
 ABC of Alcohol, Fifth Edition. Edited by Anne McCune. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd.
ABC of Alcohol, Fifth Edition. Edited by Anne McCune. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd.
How should I screen for problem drinking? February 2018, https://cks.nice.org.uk/topics/alcohol-problem-drinking/diagnosis/how-to-screen/