Objective : To evaluate the difference between self-reported and patients’ relative’s appreciation of alcohol consumption for patients with risky alcohol use.

Methods : Patients with risky alcohol use, admitted to general internal medicine wards, completed a questionnaire on drinking habits at hospital admission and 3 days later. The questionnaire contained the preceding week’s number of standard units (SU) alcohol consumption and the AUDIT C screening tool. A close relative completed a similar questionnaire about the patient’s drinking habits. The difference between self-report and proxy observed consumption was tested through Wilcoxon signed-rank test; differences in AUDIT C score were tested through paired t-test.

Results : Between March 2017 and May 2019, 46 patients were included. There was a significant difference between median self-reported (23.9 SU/week; IQR: 13.0–39.0) and relative’s (46.3 SU/week; IQR: 25.3–70.0) estimations of consumption (median difference of 12.4 SU/week; IQR 0–33.4, p < .001), and mean self-reported (6. 9; 95% CI:6.0–7.8) and relative’s (8.9, 95% CI: 8.0–9.7) estimations of the AUDIT-C Score (mean difference of 2.0; 95% CI: 1.1–2.8, p < .001).

Conclusions : Relative’s reported alcohol consumption is around two-fold higher than self-reported. Taking a history from a close relative could strengthen the confidence in the actual drinking habits of a patient.