The AUDIT-C was an effective alcohol-screening test in male and female primary care patients in each of 3 racial/ethnic groups (African American, Hispanic, and White) in this study. Moreover, the AUDIT-C was an effective screening test for the full spectrum of alcohol misuse (including alcohol use disorders and risky drinking), as well as for alcohol use disorders alone. Whereas the AUDIT-C’s sensitivity for alcohol misuse varied across racial/ethnic groups, there was no consistent pattern of variation across the racial/ethnic groups for men and women or across the 2 comparison standards. The AUDIT-C’s screening performance was equal or superior to that of the CAGE questionnaire for detection of alcohol use disorders in each of the 3 racial/ethnic groups.
This study has several important limitations. First, unlike previous validation studies, the AUDIT-C used in this study did not specify a time frame (past year) or standard drink sizes. Second, the order in which the instruments were completed may have led to underreporting on screening questionnaires, which followed in-depth interviews, and particularly on the AUDIT-C because it followed the CAGE. When alcohol-related questions are asked in sequence, patients tend to underreport their drinking and problems on questions asked later in the interviews.29
Third, although the AUDADIS is a validated measure, the comparison standard for risky drinking has not been validated, and the questions were similar to the AUDIT-C questions, which might overestimate the ability of the AUDIT-C to detect alcohol misuse. Fourth, this study included a single primary care clinic in South Texas, potentially limiting generalizability. Finally, this study used secondary data collected 14 years ago, and the validity of the AUDIT-C could have changed over time. However, we are unaware of any evidence that the performance of screening questions has changed over time, and U.S. drinking practices have been generally stable.30
However, this study has important strengths, including its oversampling of both women and racial/ethnic minorities and its high recruitment rate. Furthermore, the AUDIT-C has not been validated previously as a screening test for alcohol misuse in male and female patients from the major racial/ethnic groups in the United States: White, African-American, and Hispanic patients.
The AUDIT-C had the greatest sensitivity for detecting alcohol misuse in Hispanic women and White men and the lowest sensitivity in African-American men and women. Several factors could account for differences in the AUDIT-C’s sensitivity across racial/ethnic groups in this study. First, variation across racial groups may reflect variation of reporting of alcohol use on the AUDIT-C because of differences in drinking patterns in the racial/ethnic groups studied or differences in stigma or cultural norms across the groups. Second, the observed variation might reflect differences in the validity of the comparison standards across racial/ethnic groups.11
Finally, racial/ethnic variation in the sensitivity of the AUDIT-C could reflect confounding (e.g., by education or income) or an artifact because of multiple statistical comparisons.12,25–27
Despite differences in the AUDIT-C’s sensitivity across racial/ethnic groups in this study, we do not recommend using different cut points for African-American, Hispanic, or White patients based on this study. Previous research comparing alcohol-screening tests across racial/ethnic groups in the United States have not found consistent patterns of differences between African American, Hispanic, and White patients (Supplementary Table 5
suggesting that differences in sensitivity might reflect local factors. Moreover, it would be impractical to vary screening cut points based on race/ethnicity as well as gender in many clinical settings. For these reasons, we recommend using the validated AUDIT-C cut points of greater than or equal to 3 in women and greater than or equal to 4 in men for most settings. However, the choice of the cut point for a specific setting can be varied depending on the prevalence of alcohol misuse in that setting and the balance between the benefits of true-positive screens and the costs of false-positive screens.9
The validated AUDIT-C cut points of greater than or equal to 3 in women and greater than or equal to 4 in men are often questioned because patients can screen positive with scores of 4 or 5 while reporting drinking within recommended limits. For example, reporting drinking 4 or more days a week (question 1), 1–2 drinks a day (question 2), and never 6 or more drinks on an occasion (question 3) results in an AUDIT-C score of 4. However, although the AUDIT-C score is an effective screening test for alcohol misuse, the responses a patient reports on AUDIT-C questions numbers 1 and 2 often underestimate drinking.39
When patients undergo detailed standardized interviews, which are the gold standard for validating alcohol-screening questionnaires, the sensitivity of AUDIT-C questions numbers 1–2 for drinking more than 14 drinks a week is only 54%.39
Additionally, among male outpatients with AUDIT-C scores of 4–5, 25% who reported no prior alcohol treatment or involvement in Alcoholics Anonymous and 46% of those with prior alcohol treatment reported problems because of drinking in the past year on the remainder of the AUDIT.40
In addition, among male outpatients under 50 years old, those who scored 4–5 on the AUDIT-C were at increased risk for subsequent hospitalization for liver disease, upper gastrointestinal bleeding, or pancreatitis compared with drinkers who screened negative on the AUDIT-C.41
Therefore, the fact that the AUDIT-C score identifies patients with alcohol misuse who do not report drinking above the daily or weekly limits on the individual AUDIT-C questions is actually one of the AUDIT-C’s strengths.
To summarize, this study demonstrates that the brief AUDIT-C is an effective 3-item screening test for detecting the full spectrum of alcohol misuse in African-American, Hispanic, and White patients. Moreover, although the AUDIT-C does not explicitly ask about problems because of drinking, the AUDIT-C was an effective screen across all racial/ethnic groups for identifying men and women who met diagnostic criteria for alcohol abuse or dependence.