Upper Airway Stimulation for Obstructive Sleep Apnea: Self-reported Outcomes at 24 Months.

Objectives: To evaluate the long-term (24-mo) effect of cranial nerve upper airway stimulation (UAS) therapy on patient-centered obstructive sleep apnea (OSA) outcome measures. Methods: Prospective, multicenter, cohort study of 126 patients with moderate to severe OSA who had difficulty adhering to positive pressure therapy and received the surgically implanted UAS system. Outcomes were measured at baseline and postoperatively at 12 mo and 24 mo, and included self-and bedpartner-report of snoring intensity, Epworth Sleepiness Scale (ESS), and Functional Outcomes of Sleep Questionnaire (FOSQ). Additional analysis included FOSQ subscales, FOSQ-10, and treatment effect size. Results: Significant improvement in mean FOSQ score was observed from baseline (14.3) to 12 mo (17.3), and the effect was maintained at 24 mo (17.2). Similar improvements and maintenance of effect were seen with all FOSQ subscales and FOSQ-10. Subjective daytime sleepiness, as measured by mean ESS, improved significantly from baseline (11.6) to 12 mo (7.0) and 24 mo (7.1). Self-reported snoring severity showed increased percentage of "no" or "soft" snoring from 22% at baseline to 88% at 12 mo and 91% at 24 mo. UAS demonstrated large effect size (> 0.8) at 12 and 24 mo for overall ESS and FOSQ measures, and the effect size compared favorably to previously published effect size with other sleep apnea treatments. Conclusions: In a selected group of patients with moderate to severe OSA and body mass index <= 32 kg/m2, hypoglossal cranial nerve stimulation therapy can provide significant improvement in important sleep related quality-of-life outcome measures and the effect is maintained across a 2-y follow-up period.