The validity and usefulness of the Japanese version of the Calgary sleep apnea quality of life index in patients with obstructive sleep apnea hypopnea syndrome.

ABSTRACT

OBJECTIVE: The main purpose of this study was to translate the Calgary sleep apnea quality of life index (SAQLI) and to evaluate the reliability, validity and responsiveness of the Japanese version of the SAQLI (SAQLI-J). METHODS: Translation of the SAQLI questionnaire into the SAQLI-J questionnaire was performed following the guidelines of cross-cultural adaptation of health-related quality of life (QOL) measures. All patients completed the following questionnaires both at baseline and three months later the SAQLI-J, the medical outcome survey short form (SF-36) and the Epworth sleepiness scale (ESS). The SAQLI-J was conducted by an interviewer. PATIENTS One hundred and fifteen obstructive sleep apnea hypopnea syndrome (OSAHS) patients were recruited into the present study. RESULTS: The internal consistency and test-retest reliability of the total SAQLI-J scores (SAQLI-J total) were both excellent. Regarding construct validity, the SAQLI-J was tested by measuring the inter-domain correlation between the SAQLI-J domains and the SF-36 domains. All of the SAQLI-J domains and the SAQLI-J total were found to be moderately to highly correlated with the domains of the SF-36. Moreover, the responsiveness of the SAQLI-J total measured according to the standardized response mean was found to be moderate, and the SAQLI-J was found to be more responsive than the SF-36 for detecting changes in the QOL after continuous positive airway pressure treatment. CONCLUSION: The results suggest that the SAQLI-J is a valid, reliable and responsive health-related QOL questionnaire for use in Japanese OSAHS patients.