Spreading Interviews Over Time in Health Surveys: Do Temporal Variations of Self-Reported Alcohol Consumption Affect Measurement?

Abstract

Objective. To address systematic variations related to the day of the interview in self-reports of alcohol consumption in telephone health surveys. The investigations include temporal clustering effects, prediction of alcohol consumption and variations across days by characteristics of respondents and interviewing period, and sensitivity to variations of measurements instruments. Method. Data at baseline collected in Spring 1999 from 2846 participants in a longitudinal probabilistic general-population survey in Switzerland were used. The study is representative for drinkers in Switzerland. Alcohol consumption measures include a 6-month quantity frequency and a 1-week graduated frequency measure. Results. Evidence for systematic variations in self-reports related to the day of interview was found on the graduated-frequency measure even after controlling for sample characteristics. Similar variations on the quantity frequency measure were found, but were no longer significant after statistical control of the sample characteristics. Conclusions. Statistical inference in alcohol survey research by telephone interviews based on graduated-frequency measures with short reference period may be plagued with errors related to clustering effects of the day of the interview. Temporal aspects of conducting the fieldwork should therefore be accounted for in statistical analysis.

Keywords:

• alcohol
• survey design
• measurement
• self-reports
• temporal variations

Additional information

Notes on contributors

Jean-Luc Heeb

Jean-Luc Heeb, MA, MS, holds degrees in sociology, anthropology, and mathematics. He is a research associate at the Department of Epidemiology and Statistics at the Swiss Institute for the Prevention of Alcohol and Drug Problems (SIPA). Before joining SIPA, he worked as a teaching and research assistant at Lausanne University and participated in research projects of the Swiss National Science Foundation (SNSF). His current interests are directed towards the analysis of longitudinal survey data, the price-sensitivity of alcoholic beverages, complex survey designs, and the measurement of alcohol consumption.

Gerhard Gmel

Dr. Gerhard Gmel, is a senior scientist at the Swiss Institute for the Prevention of Alcohol and Drug Problems, where he codirects the Institute's research department. His doctorate is in psychology and methodology, with an emphasis on time series analysis, and he received a postgraduate degree as Master of Science in Statistics in 1999. He is PI of several large-scale health surveys in Switzerland, and plays a leading role in international collaborative projects. Recently he became the centralized data bank manager and analysis coordinator of the European concerted action “Gender, Culture and Alcohol Problems: Multi-national Study,” which collaborates with the WHO and the International Research Group on Gender and Alcohol. This project currently has data sets for more than 30 countries. His interests are in large-scale general population surveys on alcohol, tobacco, and drug use, and specifically in measurement issues, statistical modeling, and survey methodology.