THE VALIDITY OF THE DUTCH DLEEP DISORDERS QUESTIONNAIRE (SDQ)

The Sleep Disorders Questionnaire (SDQ) is a 176-item questionnaire de signed to diagnose the presence of common sleep disorders. This study set out to assess the validity of a Dutch translation of the SDQ. Scor es on 145 questionnaires were analyzed. A cluster analysis of these sc ores revealed the following clusters: healthy, depression, insomnia, n arcolepsy, and apnea. The cluster classification proved correct for 67 % of the subjects, as determined on the basis of polysomnography. Thes e results show that the Dutch SDQ is a reasonably valid instrument for diagnosing sleep disorders. (C) 1998 Elsevier Science Inc.