Objective: The main symptom of sleep apnea-hypopnea syndrome (SAHS) is excessive daytime sleepiness. The self-administered Functional Outcomes of Sleep Questionnaire (FOSQ) was designed to evaluate the impact of sleepiness on a patient's daily life. The aim of this study was to determine the scores of patients with SAHS and of healthy individuals on the Spanish version of the FOSQ and to assess its usefulness for evaluating the impact of excessive sleepiness in patients with suspected SAHS.
Population and methods: Thirty-one patients with SAHS diagnosed by conventional polysomnography and 31 healthy individuals were included in the study. The following data were collected: patient information; use of tobacco, alcohol, or street drugs; blood pressure; and sleep schedule. Sleepiness was assessed on the Epworth Sleepiness Scale and the impact of sleepiness on activities of daily living by the FOSQ.
Results: Patients with SAHS (apnea-hypopnea index, 57) had a mean FOSQ total score of 88.7; healthy individuals had a mean score of 110.9 (P< .001) Significant differences were found between the 2 groups on all the FOSQ subscales, except for the one that measured social outcome. There was a moderate correlation between the 2 questionnaires (r=--0.54; P=.01) and between FOSQ and the AHI (r=--0.39; P=.05). While the capacity to predict SAHS, based on receiver operating characteristic curves was greater for the Epworth Sleepiness Scale than for the FOSQ (area under the curve, 0.91 and 0.77, respectively), the diagnostic yield increased when both questionnaires were considered together.
Conclusions: We obtained FOSQ reference scores for Spanish patients with SAHS and for healthy individuals. The study showed that the Spanish version of the FOSQ is a good instrument for assessing the impact of excessive sleepiness on activities of daily living in patients with suspected SAHS.