Of the 1,244 children undergoing screening polysomnography , 464 ( 37 % ) were eligible ( 2 AHI < 30 or 1 obstructive apnea index [ OAI ] < 20 and without severe oxygen desaturation ) and randomized ; 129 ( 10 % ) were eligible but were not randomized ; 608 ( 49 % ) had AHI/OAI levels below entry criteria ; and 43 ( 3 % ) had levels of OSAS that exceeded entry criteria .