Internal consistency and validity of the Spanish version of the "Quebec Sleep Questionnaire" quality-of-life questionnaire for obstructive sleep apnea.
BACKGROUND
There is no specific health-related quality of life (HRQL) questionnaire that has been validated in Spanish for its use in patients with sleep apnea-hypopnea syndrome (SAHS). The objective of the present study was to validate the Spanish version of the Quebec Sleep Questionnaire (QSQ).


METHODS
A multi-center study including a group of patients with SAHS (AHI≥5) referred to the Sleep Unit. All patients completed the following questionnaires: SF-36, FOSQ, QSQ and Epworth scale. Internal consistency, construct validity, concurrent validity, predictive validity, repeatability and responsiveness to change of the QSQ (32 items in five domains: daytime sleepiness, diurnal symptoms, nocturnal symptoms, emotions, and social interactions) were assessed.


RESULTS
A hundred twenty one patients were included in the study (mean age: 57 ± 13; mean Epworth: 9 ± 4; mean Body Mass Index (BMI): 28 ± 3 kg·m(-2) and mean AHI: 36 ± 20 hour(-1)). The factorial analysis showed a construct of five factors with similar distribution to the original questionnaire domains. Internal consistency (Cranach's alpha between 0.78 and 0.93 for the different domains), concurrent validity (compared to SF-36, Epworth scale and FOSQ), predictive validity of SAHS severity and test-retest reliability were appropriate. The test showed good responsiveness to change in diurnal (P=.003) and nocturnal symptoms domains (P=.02).


CONCLUSIONS
The Spanish version of the QSQ is a valid HRQL measure with appropriate psychometric properties for use in patients with SAHS and is responsive to change in symptoms domains.
Servicio de Neumología, Hospital Universitario Doctor Peset, Valencia, España. PabloCatalanSerra@gmail.com
Pablo
P
Catalán
Amparo
A
Martínez
Alberto
A
Herrejón
Eusebi
E
Chiner
Miguel Ángel
MÁ
Martínez-García
José Norberto
JN
Sancho-Chust
Ricardo
R
Peris
Cristina
C
Senent
Rafael
R
Blanquer
Jose Manuel
JM
Tomás
D000328:Adult; D000368:Aged; D045422:Continuous Positive Airway Pressure; D006970:Disorders of Excessive Somnolence / Q000209:etiology; D004644:Emotions; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D007802:Language; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011446:Prospective Studies; D011788:Quality of Life; D015203:Reproducibility of Results; D012494:Sampling Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000453:epidemiology / Q000523:psychology* / Q000628:therapy; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014175:Translating