This study evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for treating moderate-to-severe obstructive sleep apnea in patients who struggled with adherence to continuous positive airway pressure (CPAP) therapy. The study included 126 participants, with a mean age of 54.5 years and a mean body-mass index (BMI) of 28.4. The primary outcomes were the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI), which showed significant reductions at 12 months (AHI: 68% decrease; ODI: 70% decrease). Secondary outcomes, including the Epworth Sleepiness Scale and the Functional Outcomes of Sleep Questionnaire (FOSQ), also demonstrated improvements. A randomized, controlled therapy-withdrawal trial further confirmed the effectiveness of upper-airway stimulation, with a significant increase in AHI scores in the group that discontinued therapy. The overall rate of serious adverse events was less than 2%. The study concluded that upper-airway stimulation is a safe and effective treatment for moderate-to-severe obstructive sleep apnea, providing significant improvements in both objective and subjective measures of severity.This study evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for treating moderate-to-severe obstructive sleep apnea in patients who struggled with adherence to continuous positive airway pressure (CPAP) therapy. The study included 126 participants, with a mean age of 54.5 years and a mean body-mass index (BMI) of 28.4. The primary outcomes were the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI), which showed significant reductions at 12 months (AHI: 68% decrease; ODI: 70% decrease). Secondary outcomes, including the Epworth Sleepiness Scale and the Functional Outcomes of Sleep Questionnaire (FOSQ), also demonstrated improvements. A randomized, controlled therapy-withdrawal trial further confirmed the effectiveness of upper-airway stimulation, with a significant increase in AHI scores in the group that discontinued therapy. The overall rate of serious adverse events was less than 2%. The study concluded that upper-airway stimulation is a safe and effective treatment for moderate-to-severe obstructive sleep apnea, providing significant improvements in both objective and subjective measures of severity.