[Pre-test probability of obstructive sleep apnea]

The obstructive sleep apnea syndrome (OSAS) is a condition characterized by repeated breathing pauses during sleep and associated with sleep fragmentation, intermittent hypoxia and increased, cardiovascular risk. The diagnosis of OSAS requires polysomnography, an expensive and time consuming technique, which still represents the gold-standard method. Several predictive mathematical models have been developed for the prediction of OSAS. These models combine subjective parameters (such as sleepiness, witnessed apneas and snoring), morphometric data (body mass index, neck circumference and cephalometric measures), associated co morbidities (such as hypertension), and oximetry data.