RESUMEN
Background: The Epworth Sleepiness Scale (ESS), Sleep Apnea Scale of Sleep Disorders Questionnaire (SA-SDQ), and Pittsburgh Sleep Quality Index (PSQI) are widely used in English speaking countries for sleep problem screening. However, there is no officially validated Thai-version of sleep questionnaires available. Objective: To provide standard Thai version of three sleep questionnaires and find cut-off level to screening sleep problems in Thai population. Material and Method: We used Mapi Research Institute Methods for translation from original language to Thai questionnaire. Then, test-retest reliability analysis was performed. Finally, we collected data from patients who underwent polysomnography in Phramongkutklao Sleep Lab Centre between June and August 2011. Cut-off value to screen population at risk for sleep-related disorder was researched. Results: The questionnaires were translated with very good inter-rater agreement. Cut-off of ESS, SA-SDQ, and PSQI suggested sleep disorders would be 9, 27, and 6.5 respectively. Conclusion: Sleep disorder questionnaires including ESS, SA-SDQ, and PSQI were translated into Thai with high validity, reliability, and accuracy.