PREVALENCE OF SLEEP DISTURBANCES AMONG YOUNG-ADULTS IN 3 EUROPEAN COUNTRIES

The aim of this investigation was to study the geographic variation in sleep complaints and to identify risk factors for sleep disturbances in three European countries: Iceland (Reykjavik), Sweden (Uppsala and Goteborg) and Belgium (Antwerp). The study involved a random populatio n of 2,202 subjects (age 20-45 years) who participated in the European Community Respiratory Health Survey. The subjects answered a question naire on sleep disturbances. Participants in Iceland and Sweden also e stimated their sleep habits and sleep times during a period of 1 week in a sleep diary. Habitual (greater than or equal to 3/week) difficult ies inducing sleep (DIS) were reported by 6-9% and early morning awake nings by 5-6% of the subjects. The estimated number of awakenings and the prevalence of nightmares was significantly lower in Reykjavik. Par ticipants in Reykjavik went to bed at night and woke in the morning ap proximately 1 hour later than participants at the Swedish centers (p < 0.001). Symptoms of gastroesophageal reflux (GER) were associated wit h DIS (odds ratio [OR] = 2.7), nightmares (OR = 4.4), longer sleep lat ency and frequent nocturnal awakenings. Smoking correlated positively to DIS (OR = 1.8) and estimated sleep latency. We conclude that the pr evalence of DIS was fairly similar at these four European centers but that there was a variation in the prevalence of nightmares and nocturn al awakenings. The significant correlation between reported GER and su bjective quality of sleep should be followed up in studies using objec tive measurements.