It's too soon to tell the impact of a Medicare policy change affecting beneficiaries who are diagnosed via a home test as having obstructive sleep apnea, local sleep disorder experts said yesterday.

Under the change announced March 13, Medicare will expand coverage for treatment -- the most common is by continuous positive airway pressure, or CPAP, devices -- to beneficiaries diagnosed with take-home sleep tests.

Obstructive sleep apnea, or OSA, is a condition in which a person temporarily stops breathing, sometimes for as long as a minute at a time, as throat muscles temporarily collapse. OSA usually is diagnosed by counting the number of sleep disturbances that occur during a specific time period. It is most common in men older than 40, causes snoring and affects the quality of sleep.

A CPAP device provides air pressure through a face mask to help keep the breathing passage open during sleep.

The prior Medicare policy only reimbursed those diagnosed with OSA in the laboratory setting of a hospital or private clinic.

The take-home test is less comprehensive, using just a handful of electrodes, compared with the 16 to 18 electrodes of a laboratory test, called polysomnography. On the other hand, a take-home test is about 35 percent cheaper to administer and also allows the subject the comfort of sleeping in his or her own bed.

"It could be a good thing, but it could be bad, depending how [the policy] is implemented, what kind of monitors are used, and who's looking at the data and doing the interpretation," said Dr. Lewis Kline, director of the Center for Sleep Disorder at Western Penn Hospital.

"It could turn into a bonanza [for the burgeoning sleep device industry], but care could be very poor if competent people are not doing the readings," Dr. Kline added.

"Medicare traditionally has not specified what kind of doctor should do what tests ... my point being that sleep studies require some knowledge to read, and I wonder who's going to be looking at these and sending them on for CPAP therapy.

"We need to see the [sub-]policies."

Dr. Daniel Shade, medical director of the Allegheny General Hospital Sleep Lab, agreed that the issue is how the portable home tests are done: which patients are tested and who is evaluating the data.

He said only a select group should be candidates, that the data have been proven more accurate for people who have moderate to severe sleep apnea and no other medical conditions.

"Otherwise, false positives are possible," he said, adding that without a full polysomnogram, other sleep disorders, for example, could lie hidden and would not be treated correctly. This occurs in older people in particular, he said.

Dr. Shade cautioned against indiscriminate use of the portable tests.

"You need the right data in the right people," he said. "If you're going to do these portable, limited studies, you have to pick the right population and they should be ordered by a sleep medicine expert who can provide the correct interpretation of results."

He said sleep medicine specialists, certified by the American Board of Medicine, have found that following up on their patients from sleep centers also improves the chances of them complying with doctors' advice and treatments.

It is believed private insurers will follow Medicare's lead, which might cut into business at independent and hospital sleep labs.

Dr. Kline doesn't buy it.

"People still have to go to a lab to get their CPAP adjusted, to get their CPAP prescriptions set," he said. "It's always interesting to me how policy sometimes has just the opposite effect of what was intended."

Medicare said in a release about its policy change, which was first proposed in December, that up to 4 million Medicare beneficiaries suffer from some form of OSA. Overall, according to the National Institutes of Health, about 18 million Americans have sleep apnea, and many of those cases are undiagnosed.