Psychometric evaluation of the Brazilian-Portuguese version of the Functional Outcome of Sleep Questionnaire 10 (FOSQ-10) in patients with obstructive apnea

Objective: Perform the validation and psychometric evaluation of the Brazilian-Portuguese translation of the Functional Outcome of Sleep Questionnaire 10 (FOSQ10). Materials and methods: 182 patients (65 females 48.3 ± 14.4 years and 117 males 46.9 ± 12.4 years), were evaluated by sleep physicians suspected of having Obstructive Sleep Apnea, underwent polysomnography and completed the FOSQ-10 and the Epworth Sleepiness Scale. APA & NCME, 2014 was used to validate the data as the American Educational Research Association recommended. Results: Quality indicators such as Bartlett's test of sphericity (χ2 = 1108.2; gL = 45; p = 0.000010) and KMO (0.83), and adherence measures, attest to the quality of the model. The indicators TLI (0.97), CFI (0.98), and RMSEA (0.04) fall within the expected values. Using the Eigenvalue > 1 technique, two factors explain 53% and 13.3% of the variances. In the Parallel Analysis technique, a single factor explained 59.4653% of the random variance, and the Unidimensionality indicators UniCo = 0.921, ECV = 0.822, and MIREAL = 0.253, were supported. Construct Validity: reliability coefficients Cronbach’s α = 0.87, McDonald’s ordinal Omega index 0.9, and the Composite Reliability 0.891 were satisfactory. Convergent validity: There was a significant Spearman correlation between FOSQ-10 and the Epworth Sleepiness Scale (r = 0.364 [−0.487; −0.226]). Criterion validity: Was not possible to differentiate the groups based on the severity of AHI using FOSQ-10P. Conclusions: The Brazilian translation of FOSQ-10 is valid and reliable for identifying significant effects of excessive daytime sleepiness in patients with Obstructive Sleep Apnea. Level of evidence: 2.