LAUSR

BACKGROUND Obstructive sleep apnea is prevalent during a time of critical neural repair following traumatic brain injury (TBI). The diagnostic utility of existing sleep studies is needed to inform clinical management during acute recovery from TBI. RESEARCH QUESTION This study aimed to evaluate the non-inferiority and diagnostic accuracy of a portable Level 3 sleep study relative to Level 1 polysomnography in hospitalized neurorehabilitation patients with traumatic brain injury. STUDY DESIGN and Methods: This is a prospective clinical trial conducted at six TBI Model System study sites between 05/2017 and 02/2019. Of 896 admissions, 449 were screened and eligible for the trial with 345 consented. Additional screening left 263 eligible for and completing simultaneous administration of both Level 1 and 3 sleep studies with final analyses completed on n=214 (median age=42; ED Glasgow Coma Scale=6; time to PSG=52 days). RESULTS Agreement was moderate to strong (weighted kappa = 0.78, 95% CI = 0.72, 0.83) with the misclassification commonly occurring with mild sleep apnea due to underestimation of AHI. A majority of those with moderate to severe sleep apnea were correctly classified (n=54/72). Non-inferiority was not demonstrated: the minimum tolerable specificity of 0.5 was achieved across all AHI cutoff scores (LCL range = 0.807-0.943) but the minimum tolerable sensitivity of 0.8 was not (LCL range = 0.665-0.764). INTERPRETATION While the non-inferiority of Level 3 portable diagnostic testing relative to Level 1 was not established, there was strong agreement across sleep apnea indices. A majority of those with moderate to severe sleep apnea were correctly identified; however, there was risk of misclassification with Level 3 sleep studies underestimating disease severity for those with moderate to severe AHI and disease presence for those with mild AHI during early TBI neurorehabilitation.