Effects of telephone versus face-to-face survey modes on reports of alcohol-related attitudes, harms and alcohol consumption

Aims: To assess the effect of telephone vs. face-to-face interview modes on reports of alcohol-related attitudes, harms and alcohol consumption. Methods: Two simple random samples of persons aged 15–69 were drawn for the Finnish Drinking Habits Survey with sample sizes of 800 for the telephone interviews and 3750 for the face-to-face interviews. Results: There was an estimated mode effect for the whole population in 4 out of 28 descriptive measures. They did not show a consistent pattern, but some support was found for a lower level of reported alcohol-related harm in telephone interviews than in face-to-face interviews. In the subgroup analysis, our results showed differences in 9 out of 68 comparisons. The most consistent ones of these differences were between the age groups. Conclusion: The results of the alcohol-related measures in the telephone interviews were reasonably well in line with the results of the face-to-face interviews.