[A simplified Chinese version of the Quebec sleep questionnaire was evaluated for reliability and validity]

To develop a simplified Chinese version of the 32-item Quebec sleep questionnaire (QSQ) and to examine the reliability and validity.

A cross-sectional sample of 141 patients [22 simple snorers and 119 obstructive sleep apnea hypopnea syndrome (OSAHS)] and a longitudinal sample of 55 patients [35 in uvulopalatopharyngoplasty (UPPP) group and 20 in control group] completed the simplified Chinese version of QSQ for assessment of its feasibility, reliability, validity and responsiveness.

QSQ had good feasibility. All internal consistency coefficients exceeded 0.65. Intraclass correlation coefficients of five domains for test-retest reliability ranged from 0.82 - 0.91. There were significant differences in four domains (daytime sleepiness, diurnal symptoms, nocturnal symptoms and social interactions) among patients with different severity of apnea hypopnea index (AHI) and lowest saturation of arterial oxygen (LSaO2, P < 0.01 or < 0.05). Correlations between QSQ scores and five domains and Epworth sleepiness scale (ESS) were statistically significant (P < 0.01). Correlations between QSQ scores and three domains (daytime sleepiness, nocturnal symptoms and social interactions) and polysomnography (PSG) indices (AHI and LSaO2) were statistically significant (P < 0.05). There were significant differences in scores of five domains of patients between at baseline and after UPPP. There were significant differences in change scores of five domains between patients who were treated and those who were not.

The simplified Chinese version of QSQ offers good reliability, validity and responsiveness and can be used as a OSAHS-specific instrument to assess impact of illness and treatment effectiveness in OSAHS patients.