Assignment of Alcoholic Beverages in the Munich Composite International Diagnostic Interview (M-CIDI): an Online Survey Among German Students and Non-students

The objective of this study is to investigate whether the materials presented during alcohol consumption assessment sufficiently aid interviewees in categorizing the beverages they consumed during their lifetime. In the cross-sectional “AF-CIDI” online survey, N = 162 adult drinkers (61% female, 40% non-students) aged 27 ± 8.2 years assigned beverages names to one of ten categories of the Munich Composite International Diagnostic Interview (M-CIDI) supplementary list. Eighty percent of these 4465 laymen beverage assignments were correctly classified in accordance with expert assignments. Assignment correctness was associated with confidence, and, to a smaller degree, exposure, prevalence, utility of examples, and age group. Alcohol by volume (ABV) estimates based on subjective classifications differed 2.7 points on average from CIDI-based ABVs, which in turn differed 3.6 points on average from real ABVs measured with Fourier transform infrared spectroscopy. Beverages with low lifetime prevalences (≤ 25%) were frequently misclassified. This understudied response bias might be part of the well-known underreporting phenomenon.