OBJECTIVES : Hypoglossal nerve stimulation (HNS) was recently introduced for patients with OSA and is experiencing increased adoption. The objective of this study was to conduct a systematic review and meta-analysis to evaluate effects on health-related quality of life with different validated instruments that are used to document subjective outcomes.

METHODS : A systematic literature search in MEDLINE and Web of Science was performed to identify studies, which describe quality of life effects after HNS treatment. Using the PRISMA guidelines, twenty-one studies with 25 groups and 1,630 patients were identified, which used at least one of the following four instruments: Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), Calgary Sleep Apnea Quality of Life Index (SAQLI) and Pittsburgh Sleep Quality Index (PSQI). A meta-analysis was performed for each of the instruments in random-effect models.

RESULTS : Hypoglossal nerve stimulation leads to pronounced improvements in HRQoL. The observed effects varied across studies and instruments. The strongest impacts were observed on daytime sleepiness (ESS): Mean difference (MD) = -5.067, 95% CI -4.242 to 5.710. MD for daytime functioning (FOSQ) was 3.121, 95% CI 2.581 to 3.662; MD for sleep apnea related quality of life (SAQLI) was 1.241, 95% CI 0.307 to 2.175 and MD for sleep quality (PSQI) was -1.771, 95% CI -0.397 to 3.145. Heterogeneity varied for the different endpoints (I^2 0-86.55).

CONCLUSIONS : HNS therapy significantly improves quality of life in patients with OSA and CPAP intolerance across all included studies. Major and significant effects on daytime sleepiness, daytime functioning, and sleep apnea related quality of life as well as sleep quality were detected. The power of the results varied though among the used instruments. Daytime sleepiness and daytime functioning effects reached or exceeded what is considered a clinical important difference in patients with OSA.