Objective: To develop a Thai version of the Sleep Apnea Quality of Life Index (SAQLI-T) and evaluate its reliability and validity.

Materials and Methods: A cohort of 506 Thai sleep apnea patients were recruited. All participants were required to complete the short form questionnaire on various aspects, or domains, of their condition, including daily functioning, social interaction, emotional functioning, and symptoms. The internal reliability of the questionnaire had been tested. In order to examine the external reliability (test-retest reliability), 30 subjects were recruited to answer the SAQLI-T twice at two weeks apart. The construct validity was compared with apnea-hypopnea index (AHI).

Results: The Cronbach’s alpha of internal reliability was 0.90 and excess 0.7 in all domains, and the intra-class correlation coefficients of external reliability were 0.93. The correlation between the construct validity and AHI was weak. However, the predictive validity of the test showed a significant lower mean of total SAQLI scores observed in participants with mild to moderate obstructive sleep apnea (OSA) compared to those with severe OSA.

Conclusion: The SAQLI-T as developed demonstrated a high level of internal consistency and a high test-retest reliability, although there was a weak correlation with AHI. A short form SAQLI is easy to use in daily practice as well as in the research settings, and therefore, it is a useful health-related quality of life measure.

Keywords: Questionnaire, Sleep apnea, Sleep-disordered breathing, Quality of life