A COMPARATIVE-STUDY OF 2 METHODS FOR THE MEASUREMENT OF ALCOHOL-CONSUMPTION IN THE GENERAL-POPULATION

Background. One of the major methodological problems in measuring alco hol consumption in a general population and in selected groups is unde rreporting. Methods. The present study is based on a general health qu estionnaire survey of a random sample of about 4000 adults aged 20-74 years in an inner-city area in each of two major Swedish cities in 199 1. The questionnaire included items both about alcohol consumption fre quency and the usual amount of intake-the commonly used quantity-frequ ency (QF) method-and other questions about the consumption during work -days and weekends during a 'normal week'-the period-specific normal w eek (PSNW) method. Results. With a few exceptions, the reported mean c onsumption and the proportion of high consumers was higher with the la tter approach, irrespective of sex, age, socio-demographic factors, sm oking and health status, i.e. for variables which are commonly used as confounders or effect modifiers. The differences between the methods was greater among women. The internal non-response rate was higher wit h the PSNW method but the non-responders had a comparatively low consu mption, when measured with the QF method. Conclusion. The PSNW method has higher validity and greater precision for the measurement of alcoh ol consumption and, thus, is superior to the QF method. The sex differ ences are notable and warrant further studies focusing on sex-related modes of answering.