Objective: To perform criterion validation of the Key Question in Portuguese for screening at-risk alcohol use among users of Primary Healthcare services.
Method: This is a psychometric study conducted with users of a Primary Healthcare service located in the city of São Paulo, Brazil. Participants responded to the Key Question which was applied in conjunction with the Alcohol Use Disorders Identification Test-C for concurrent validation and measurement of psychometric properties.
Results: The sample consisted of 518 users. The Key Question presented 59% specificity and 99% sensitivity with respect to the Alcohol Use Disorders Identification Test-C in the general population. The accuracy was 81% in relation to this instrument. There was no influence of sociodemographic variables such as gender on the psychometric properties of the Key Question.
Conclusion: The results indicate that the Key Question in Portuguese presented satisfactory psychometric qualities and suggest that its Portuguese version is as efficient for screening at-risk alcohol use as its reference standard, which subsidizes its use in Primary Healthcare.