0575 Home Sleep Apnea Test Modified Hypopnea Scoring Criteria More Accurately Correlates to Same Night In-Lab Polysomnogram

Introduction Home sleep apnea testing (HSAT) improves access and lowers cost, but diagnostic accuracy remains limited. Sensitivity/specificity for moderate-to-severe obstructive sleep apnea (OSA ) have been reported to be 80%/74%, with lower accuracy in mild disease. HSATs lack electroencephalography (EEG) and therefore the ability to score arousal-based events per AASM Recommended polysomnogram (PSG) scoring criteria. Alternative HSAT scoring criteria to improve concurrence with gold-standard PSG have been explored. We recently proposed modified scoring in which hyperpneas following qualifying hypopneas act as surrogate arousals. This enables scoring without EEG , potentially improving diagnostic performance. In this study, we prospectively evaluated this modified scoring method by performing simultaneous in-lab PSG and HSAT recordings and comparing results. Methods Patients undergoing clinically indicated PSG at our sleep center (Aug 2025–Feb 2026) also wore type 3 HSAT equipment . Recordings were time-synchronized to compare respiratory event detection between devices. Three AHI values were calculated: (1) gold-standard PSG (pAHI), (2) conventional HSAT (cAHI), and (3) modified HSAT scoring using hyperpneas after flow limitations as surrogate respiratory arousals (mAHI). Results Seventeen patients completed the protocol (23% female; age 20–57 years; pAHI 1.8–80.9/hr; BMI 20–44.5). Modified scoring improved accuracy compared to cAHI using the absolute difference in AHI from pAHI (mean absolute difference between pAHI and mAHI = 4.98/hr (SD=5.63) vs mean absolute difference between pAHI and cAHI = 7.96/hr (SD=8.59), p=0.043 for calculated paired difference). PSG agreement improved (mean mAHI difference from pAHI = -1.65/hr, p = 0.374) compared to cAHI, which significantly underestimated AHI (mean cAHI difference from pAHI = -7.28/hr, p = 0.0049). Compared to pAHI, cAHI changed OSA diagnosis in 2 (11.8%) and OSA severity in 7 (41.2%) whereas mAHI changed OSA diagnosis in 1 (5.9%) and severity in 4 (23.5%). Conclusion Modified HSAT scoring demonstrated superior alignment with PSG and mitigated AHI underestimation seen with desaturation-only scoring. Incorporating physiologically relevant respiratory events into HSAT interpretation may narrow the performance gap between home and in-lab testing and offer meaningful cost savings by negating the requirement for follow-up sleep studies or reducing the number of follow-up PSG studies needed. Additional studies are indicated to further validate these findings. Support (if any)