Evaluating changes in hypoglossal nerve stimulator use over time and long-term adherence.

Purpose: Evaluate patient phenotypes and longitudinal patterns of hypoglossal nerve stimulator (HGNS) use and identify predictors of long-term HGNS adherence.

Methods: Patients who underwent HGNS implantation for obstructive sleep apnea (OSA) from 2017 to 2023 and had available data through 9 months post-device activation were included. Adherence rate was defined as percentage of patients using the device for at least 4 h for 70% of nights. Repeated measures ANOVA and Cochran's Q tests were used to analyze changes in HGNS use over time. A k-means clustering analysis was used to identify HGNS user subgroups with shared characteristics and associations with HGNS use.

Results: A total of 59 patients were included, with a mean (SD) age of 62.7 (11.2) years, mean (SD) body mass index of 28.5 kg/m2 (3.2), and an average pre-operative apnea-hypopnea index (AHI) of 38.7 events/hour; the majority were male (78%) and White (98.3%). Patients used their HGNS devices on average for 81.1% of nights (SD 23.5%) and 362 min/night (SD 115), with 0.96 (SD 1.4) pauses/night at 9 months post-activation. The mean percentage of nights and the time/night used decreased significantly over the first 9 months (p < 0.001 for both), while pauses/night increased (p = 0.008). The estimated adherence rate was 52.5% at 9 months. The cluster analysis revealed subgroups with shared characteristics; however, clusters were not associated with HGNS use.

Conclusions: HGNS use appears to decrease over the first nine months after activation. Additional research is warranted to investigate drivers of HGNS use decrement. Given lack of a standardized definition for adherence, future studies should report more granular HGNS use metrics to facilitate comparison across studies.