The median ( quartiles ) apnea-hypopnea index at @ m was @ / h ( @ ; @ ) , values at @,@ and @,@ m , day @ and @ , respectively , were @ / h ( @ ; @ ) , @ / h ( @ ; @ ) , @ / h ( @ ; @ ) , and @ / h ( @ ; @ ) ; corresponding values of mean nocturnal oxygen saturation were @ % ( @ ; @ ) , @ % ( @ ; @ ) , @ % ( @ ; @ ) , @ % ( @ ; @ ) , @ % ( @ ; @ ) , P < @ versus @ m , all instances .