AN INTERNATIONAL STUDY ON SLEEP DISORDERS IN THE GENERAL-POPULATION -METHODOLOGICAL ASPECTS OF THE USE OF THE SLEEP-EVAL SYSTEM

The comparability among epidemiological surveys of sleep disorders has been encumbered because of the array of methodologies used from study to study. The present international initiative addresses this limitat ion. Many such studies using the exact same methodology are being comp leted in six European countries (France, the United Kingdom, Germany, Italy, Portugal, and Spain), two Canadian cities (metropolitan areas o f Montreal and Toronto), New York State, and the city of San Francisco . These surveys have been undertaken with the aim of documenting the p revalence of sleep disorders in the general population according to cr iteria of the Diagnostic and Statistical Manual of Mental Disorders, 4 th edition (DSM-IV) and the International Classification of Sleep Diso rders (ICSD-90). Data are gathered over the telephone by lay interview ers using the Sleep-EVAL expert system. This paper describes the metho dology involved in the realization of these studies. Sample design and selection procedures are discussed.