The U.S. Preventive Services Task Force has issued a draft recommendation opposing screening for obstructive sleep apnea (OSA) in adults who are asymptomatic for the breathing disorder.

The USPSTF’s opposition is based on its determination that there is insufficient evidence to assess the balance of benefits and harms of screening for OSA in asymptomatic adults in primary care settings, giving the service an “I” grade. The recommendation and a draft evidence review are available for public comment until July 11 at 8:00 p.m. EST.

The draft recommendation is the first that the USPSTF has ever made about sleep apnea, according to the draft evidence review . The recommendation “applies to asymptomatic adults (aged 18 years and older) and adults with unrecognized symptoms of OSA.” It does not apply to children, adolescents, pregnant women, persons presenting with symptoms of or concerns about OSA, those who are being referred for evaluation or treatment of suspected OSA, and those who have acute conditions that could trigger the onset of OSA.

“Reported estimates of OSA prevalence vary due to differing definitions of OSA, sampling bias, and year of study publication. A 2013 systematic review reported an estimated prevalence of 2%-14% based on four community-based studies, while two U.S.-based studies conducted in the 1990s reported an estimated prevalence of 10% for mild OSA and 3.8%-6.5% for moderate or severe OSA,” according to the recommendation .

The USPSTF was unable to find adequate evidence on the direct harms of screening for OSA or the benefits of screening for OSA in asymptomatic populations, including their magnitude.

Most primary care clinicians do not routinely screen for OSA, according to the recommendation. While the Epworth Sleepiness Scale , STOP Questionnaire , STOPBang Questionnaire , Berlin Questionnaire , and Wisconsin Sleep Questionnaire are potential screening tests for OSA, none of these questionnaires has been validated in a primary care setting.

“There is uncertainty about the clinical utility of all potential screening tools,” and the USPSTF found no studies that prospectively evaluated screening questionnaires or clinical prediction tools to report calibration or clinical utility for improving health outcomes,” the draft evidence review said.

The USPSTF also found no studies evaluating the effect of screening for OSA on health outcomes or that directly evaluated benefits or harms of screening for OSA.

The recommendation calls for further research on the health outcomes of screening for OSA in asymptomatic persons and the role of sleepiness in determining health outcomes. The following are needed:

• The identification of valid and reliable clinical prediction tools that could accurately determine which asymptomatic persons (or persons with unrecognized symptoms) would benefit from further evaluation and testing for OSA.

• Studies that evaluate the effect of OSA treatments or interventions on health outcomes that are adequately powered and have an appropriate length of follow-up.

• Studies that evaluate whether improvement in the apnea-hypopnea index leads to improvement in health outcomes. • More data on the natural history of mild sleep apnea.

The final evidence review will be used to inform the final USPSTF recommendation statement.