Study objectives: To assess predictive factors of quality-of-life (QoL) improvement and continuous positive airway pressure (CPAP) use in patients with sleep apnea-hypopnea syndrome (SAHS) after 1 year of treatment with CPAP.
Design: Observational, prospective cohort study.
Setting: Sleep unit in a university hospital.
Patients: One hundred thirty-three consecutive patients with an indication for CPAP treatment.
Measurements and results: Nottingham health profile (NHP) questionnaire, Epworth sleepiness scale score, and objective CPAP use (time counter in the CPAP device) were assessed at baseline and after 3 months and 12 months of CPAP use. Multivariate logistic regression was used to identify predictive factors of CPAP use and improved QoL. At 1 year, 101 patients (76%) were still using CPAP; of these, 88 patients (66%) completed all the follow-up questionnaires. QoL was lower before treatment, compared with the general population, and all dimensions of the NHP, except social isolation, improved significantly from baseline in patients regularly using CPAP, reaching levels comparable to those of the general population at 1 year. Only minimum oxyhemoglobin saturation at diagnostic polysomnography was associated with the degree of QoL improvement at 1 year. Only the NHP and the apnea-hypopnea index (AHI) at baseline were significantly associated with hours of CPAP use at 1 year.
Conclusions: Compared to the general population, patients with untreated SAHS had a lower QoL, which improved to the level of the general population after 3 months of CPAP therapy and persisted at 1 year of treatment with CPAP. The only predictor of QoL improvement was minimum nocturnal oxygen saturation at baseline. Higher AHI and worse QoL at baseline were predictors of hours of CPAP use.