0681 Comparison Of Upper Airway Stimulation Outcomes Between Regions And Bmi Groups From The Adhere Registry

Abstract

Abstract Introduction As factors influencing Upper Airway Stimulation (UAS) effectiveness in obstructive sleep apnea (OSA) patients are of interest, we compared changes in apnea hypopnea index (AHI) and Epworth Sleepiness Scale (ESS) based on region and baseline body mass index (BMI). Methods Patients (15≥AHI≤65) of the ADHERE registry with AHI at one-year were grouped by region (Europe (EU) vs United States (US)), and BMI (≤32kg/m2 vs 32-35kg/m2). T-tests and equivalence testing (if the former non-significant) was performed using two-one-sided t-tests. Equivalence margin for AHI was set between -5 and 5 and -2 and 2 for ESS. Results By December 2019, 553 of 1600 patients completed 1-year follow-up. Average age was 60±11, 75% male, BMI 29±4 kg/m2, ESS=11±6. Median AHI decreased from 33 to 10, median ESS decreased from 11 to 6. Response defined by 50% AHI reduction and <20 was 70%. Both regions had similar improvements in median AHI (EU: 33 to 10, US: 34 to 10, p < 0.001 vs baseline), median ESS (EU: 12 to 7; US: 11 to 6, p<0.001 vs baseline), and treatment response (EU: 71%, US: 68%). The mean AHI and ESS difference between regions met the equivalence margin. (AHI: mean difference: 0.34, CI:-1.78, 2.46, ESS: mean difference: 0.57, CI:-0.04, 1.19). Mean change in AHI at 1-year was equivalent in BMI groups (≤32 kg/m2 vs 32-35 kg/m2 respectively) median difference: -19.6 vs. -18.8; mean difference: -0.48, (CI:-3.95, 2.97) However, treatment response ratio was different; 73% vs. 60%, p=0.02, i.e. higher BMI patients were less likely to achieve AHI < 20. ESS scores were equivalent; median: 6 vs. 7; mean difference: -0.33, CI: [-1.16, 0.47]. Conclusion UAS influence on OSA severity defined by AHI and sleepiness was similar irrespective of region and BMI category, however, treatment response defined by 50% AHI reduction and <20 was greater in those with lower BMI. Support The statistical support was provided by Inspire Medical System.