Italian Quebec Sleep Questionnaire for assessing quality of life in obstructive sleep apnoea.

OBJECTIVE: To develop and validate the Italian version of the Quebec Sleep Questionnaire (I-QSQ) for assessing quality of life (QoL) in patients with obstructive sleep apnoea (OSA). METHODS: The questionnaire was translated, culturally adapted, and back-translated. Internal consistency and test-retest reliability were evaluated in patients with moderate OSA. Normative values were obtained in healthy subjects. Construct and criterion validity were assessed by comparing scores of patients and controls, and by correlating I-QSQ with the Epworth Sleepiness Scale. Responsiveness was examined in patients undergoing sleep surgery. RESULTS: One hundred-six patients and 173 control subjects completed the I-QSQ without assistance. Internal consistency was acceptable to excellent across domains (Cronbach's α = 0.71-0.9), and test-retest reliability was high (ICC = 0.88-0.96). Patients scored significantly lower than controls in all domains (p < 0.001). A negative correlation was observed between I-QSQ and Epworth Sleepiness Scale scores (r = -0.54). Post-surgical patients showed significant improvement in I-QSQ total score. CONCLUSIONS: I-QSQ is a reliable, valid, and responsive tool for evaluating QoL in Italian-speaking patients with sleep apnoea and can be effectively used in clinical practice and research.