Adherence to unilateral hypoglossal nerve stimulation and changes in Epworth Sleepiness Scale scores.

Study objectives: Effective treatment of obstructive sleep apnea depends on efficacy and adherence. The objective of this analysis was to examine the association between adherence to unilateral hypoglossal nerve stimulation (HGNS, Inspire Upper Airway Stimulation) and changes in daytime sleepiness.

Methods: Participants were adults treated with unilateral HGNS enrolled in the ADHERE Registry. All participants included in the analysis completed a final visit 1-2 years following implantation. Outcomes were the change in Epworth Sleepiness Scale (ESS) score and normalization of a baseline abnormal ESS score (baseline ESS>10 and final ESS≤10). Statistical analyses examined the association between objective therapy adherence and ESS outcomes, with multiple regression including adjustment for age, sex, race, ethnicity, body mass index (BMI), and apnea-hypopnea index (AHI)-defined responder status.

Results: The analysis included 1147 participants who were primarily middle-aged (59.7 ± 10.5 years), overweight (BMI 29.1 ± 3.7), Caucasian (95.8%), male (76.8%), and with severe OSA (AHI 35.12 ± 14.81). ESS scores decreased from 11.3 ± 5.5 at baseline to 6.9 ± 4.6 at final visit. Of those with baseline ESS>10, 68% (441/644) achieved normalized ESS scores at final visit. Multiple regression analyses showed that each additional hour/night of therapy use was associated with decrease in ESS score (0.17, p=0.045) and increased odds of normalized ESS (OR 1.13; 95% CI: 1.03-1.25). AHI response was also associated with decrease in ESS score (1.29, p<0.001) and increased odds of a normalized ESS (OR 2.29; 95% CI: 1.55-3.4).

Conclusions: Adherence to HGNS is associated with improvement in daytime sleepiness symptoms and increased odds of achieving normalization of daytime sleepiness.