Adjusting the apnea-hypopnea index in children with a low percentage of REM sleep and its potential impact on OSA diagnosis and severity.
Objective: A decrease in rapid eye movement (REM) time during polysomnography in patients with obstructive sleep apnea (OSA) can result in underestimation of apnea-hypopnea index (AHI). We propose adjusting AHI to normalized REM% in individuals with REM% ≤ 15% to avoid underdiagnosis of OSA. Methods: All children who completed diagnostic polysomnography from 2016-2023 with REM% of ≤ 15% of total sleep time were selected for adjustment. AHI adjustment was done by multiplying AHI by a normalization factor (20%)/REM%. Changes in OSA diagnosis and severity were evaluated before vs after adjustment. Intraclass comparison and Bland-Altman plots were used to evaluate agreement level of adjusted AHI vs nonadjusted AHI with REM AHI as the reference. P value < .05 was significant. Results: Of 389 children reviewed, only 79 (20%) children had low REM% of ≤ 15%. Median (range) age was 12.8 (0.9-18) years with male/female ratio 2.3/1. Mean (standard deviation) sleep efficiency was 64.7% (12.3). Mean (standard deviation) REM% was 10.5% (3.4). Median AHI (range) before AHI adjustment was 1.7 (0-44) events/h vs 4.1 (0-74.4) events/h after AHI adjustment (P < .001). Adjusted AHI had better agreement with REM-AHI (intraclass correlation = .691; 95% confidence interval: 0.58, 0.80) than nonadjusted AHI (intraclass correlation = .485; 95% confidence interval: 0.39, 0.58). AHI adjustment changed diagnosis from normal to mild OSA in 12 (15%) patients, from mild to moderate OSA in 7 (9%) patients, and from moderate to severe OSA in 9 (11%) patients (P = .044). Conclusions: Adjusting AHI in patients with low REM% to a normalized REM% can help avoid underdiagnosis of OSA and/or underestimation of its severity.
Background: Alnaimi A, Toma H, Abushahin A, Belavendra A, Abu-Hasan M. Adjusting the apnea-hypopnea index in children with a low percentage of REM sleep and its potential impact on OSA diagnosis and severity. J Clin Sleep Med. 2025;21(5):783-788.