Prevalence of obstructive sleep apnea and accuracy of type 3 home sleep apnea test for obstructive sleep apnea diagnosis in difficult-to-treat asthma

<bold>Background:</bold> Prevalence of obstructive sleep apnea (OSA) was reported to be higher in severe and difficult-to-treat-asthma. American Academy of Sleep Medicine recommended type 1 polysomnography as the OSA diagnosis modality in asthma considering asthma as a significant underlying cardiopulmonary disease. <bold>Objective:</bold> The primary objective is to assess the prevalence of OSA in patient with difficult-to-treat asthma. The secondary objective is to assess the accuracy of type 3 home sleep apnea test (HSAT) compared to type 1 polysomnography (PSG). <bold>Methods:</bold> Patient diagnosed with difficult-to-treat asthma, aged over 18 years, and experiencing persistent symptom as assessed by the Asthma Control Test (ACT) underwent type 1 in laboratory PSG and type 3 HSAT within 1 month apart. <bold>Result:</bold> A total 32 participants were included in the study. Baseline characteristic of PSG demonstrate overall apnea hypopnea index (AHI) of 21.6±15.8 and oxygen desaturation index of 21.7±15.8. Prevalence of OSA (AHI ≥ 5) was 91%. Among the OSA cases, 34.4% were classified as mild OSA, 37.8% as moderate OSA, and 27.8% as severe OSA. The type 3 HSAT was observed to have sensitivity of 79.3% and specificity of 100% for OSA diagnosis. <bold>Conclusion:</bold> Patients with difficult-to-treat asthma were observed to have a high prevalence of OSA. Compared to type 1 in-laboratory PSG, type 3 HSAT provided good sensitivity and specificity in OSA diagnosis, revealing that oxygen desaturation was the predominant respiratory events of OSA in difficult-to-treat asthma. Type 3 HSAT should be considered as the initial OSA diagnostic modality in all difficult-to-treat asthma.