Purpose of the Evidence Report Driving is a complicated psychomotor performance that depends on fine coordination between the sensory and motor systems. Many health conditions exist which have the potential to impair perception, cognition (including alertness, attitude to risk, and recall) and/or motor function and, as a result, can make driving less safe. Obstructive sleep apnea (OSA) is a relatively common disorder affecting approximately 12 million individuals in the United States, with approximately 4% of men and 2% of women in the U.S. suffering from symptomatic sleep apnea. [1-5] OSA is a disorder characterized by a reduction or cessation of breathing during sleep coupled with symptoms such as daytime sleepiness (i.e., OSA syndrome). [1, 2] Given this, OSA may culminate in unpredictable and sudden incapacitation (e.g., falling asleep at the wheel), thus contributing to the potential for crash, injury, and death. In 2007, MANILA Consulting Group conducted a systematic review of the literature under the direction of the Department of Transportation's Federal Motor Carrier Safety Administration in order to synthesize the evidence related to OSA and crash risk, as well as the effectiveness of diagnostic tests and treatment options for OSA. Since completion of this evidence report, a considerable amount of research has been conducted related to methods for the diagnosis of OSA. Much of this research has been conducted in response to a push by some to identify options for the diagnosis of OSA which could be used as an alternative to polysomnography (PSG). The purpose of this evidence report is to synthesize the research that has been conducted since the last review related to diagnostic alternatives to PSG for the identification of OSA. Specifically, this report focuses on two key questions: Key Question# 1: Are there screening/diagnostic algorithms available that will enable examiners to identify those individuals at higher risk for moderate-to-severe OSA, thereby referring these individuals for confirmation by PSG? Key Question #2: Are portable monitoring devices comparable to in-laboratory, technician-attended polysomnography (PSG) in the identification of individuals with OSA?