Are you more of like a honk-shoo honk-shoo Or more of like a mimimi? It’s an important question! No it’s actually a trick
question because either way, if you sound like that when you sleep, you might be at risk of having
obstructive sleep apnea. You thought it was fun… but it’s not! Because, in addition to
loud and irritating snoring, It can come with some real health risks. And the current standard of
care is a machine called a CPAP. It works by using pressurized air to keep your breathing consistent while you sleep. These machines are expensive and
people don’t like using them, but at least the quality of
clinical evidence for them is… poor. Wait… because like many things in science… It's complicated. [♪ INTRO] Obstructive Sleep Apnea, or OSA, affects around 1 billion people worldwide. It’s a condition in which your
throat muscles relax too much in your sleep and block your airways, causing you to stop and start breathing several times throughout the night. Besides all the problems that come
with getting poor quality sleep, untreated OSA has been linked to complications such as cardiovascular events
and high blood pressure, and it’s associated with diabetes too. CPAP, which stands for continuous
positive airway pressure, is currently used as the
standard of care to gently force your airways to stay open in your sleep. The treatment generally includes
a mask to fit over your face, along with tubing and machinery to
filter and pressurize the air.
While they are the most common treatment, CPAP machines are not exactly a popular option. They can be uncomfortable and noisy, with enough issues to fill up whole web pages of tips on how to improve their fit and feel. These machines will also run you on average 800 US dollars without insurance, which doesn’t include the ongoing
need for replacement parts. So, what with it costing you an arm and a leg, you probably want to be
darned sure that this machine is actually able to fix all the
health conditions that it claims to. And that’s what a review published
in 2022 by the U.S. Department of Health and Human Services
set out to investigate. The team analyzed 52 publications
to figure out whether CPAP is effective in reducing the long
term health effects of OSA. And they reported that there
wasn’t a ton of strong evidence to support CPAP machines
actually leading to improvements in most of the outcomes they looked at. To be clear, they did not say that there is overwhelming evidence against CPAP machines. Rather, the studies were too
contradictory or conflicting in their design to be able to
say much of anything at all. The studies were inconsistent
in their definitions of OSA and breathing measurements, even though there are published standards that could totally be used. Even some papers that cited the
same source for their definitions didn’t end up using the same criteria as another. The studies also did not properly
address whether the benefits of CPAP differed based on the
severity of the participants’ OSA or other potential confounders. Overall, it may come as no surprise that the report recommended more research. Specifically, we need more high-quality studies to confirm the impact of
CPAP, and we need to be clear on which patients would benefit
most from using CPAP devices. Not everyone was happy about this report. Physicians feared that people
would misinterpret the results to mean that CPAP machines
definitively do not work, which could lead to insurance providers like Medicare refusing to pay for them. In fact, sleep doctors stand by CPAP machines as the gold-standard treatment for OSA. And one reason might be that doctors look at the evidence a little differently
than the report’s authors. For example, the report only
included studies that conducted follow ups for physical outcomes
after at least 12 months. And there weren’t any such papers
with enough statistical power to look at the effect of
CPAP on high blood pressure. But, in a meta-analysis published
in 2024 that included studies with shorter follow up times,
researchers found that CPAP treatment was associated with reduced blood
pressure in less than three months. In fact, you can dig up similar
contradictions for nearly everything you could want
to study about CPAP and OSA. Which is to say, you can, and we did. When we tried to research exactly
what long-term health conditions are definitely improved by using CPAP machines, we had, like, a really hard
time finding much consensus. Even an outcome as fundamental
as daytime sleepiness didn’t yield consistent findings. One study in Australia included
31 participants who used their CPAP machines for an impressive
7 or more hours a night. 20% of those participants still
did not come down to typical levels of daytime sleepiness, and
more than half did not reach typical levels of daily
functioning due to sleepiness. On the other hand, research
groups in India and Taiwan were able to find significant
improvement in daytime sleepiness in their 34 and 47 participants, respectively. And while all the research groups
used the same questionnaire to evaluate sleepiness, their analysis
methods were slightly different, which makes it still difficult
to directly compare.
So before we even ever get to
stuff like cardiovascular disease, it’s already incredibly hard
to give one digestible answer to the question of whether CPAP works. Does it make you less sleepy? Yes or no? So what gives? Why is the golden child of
obstructive sleep apnea treatment not showing us consistent
results among study participants? Well, study design is one issue. But we also need to turn to
the definitions of two terms: efficacy versus effectiveness. Which sound the same, I know. Maybe one is just like the pretentious
older sibling of the other. But in the lingo of medical interventions, efficacy is basically how well a treatment does under perfect conditions, and effectiveness is how well it
actually works in the real world. In the case of OSA, efficacy
is the absolute ability of a CPAP machine to stop your airways
from closing while you sleep. Effectiveness takes into account both efficacy and how well people actually stick
to using the machine as prescribed. And since we’ve established that CPAP machines can be hard to get used to,
it may not be surprising that their effectiveness is a
lot lower than their efficacy. What, you don’t want to be attached to an uncomfortable face-hugger all night? Get used to it. To count as being “adherent” to
your CPAP machine prescription, you only need to be using it
for at least 4 hours a night. Studies could be averaging the results of everyone who qualifies as “adherent,” whether they’re using their CPAP
machines for four hours or eight! And as Health and Human Services
pointed out in their review, in most studies, a lot of participants
didn’t even clear the four hour bar. So the results between studies
could have been inconsistent with each other due to inconsistent CPAP use. Let’s look at one more health
outcome to drive this point home. In that Health and Human Services report, they found that there was not
enough significant evidence to say that CPAP can reduce cardiovascular
events in patients with OSA. They looked at 12 studies
to come to this conclusion, of which only two found a reduced risk of cardiovascular events with proper CPAP use. When looking at all 12
together, the authors concluded there wasn’t strong enough evidence
to say anything conclusive. Now, a different meta-analysis
looked at three of those 12 studies. And by themselves, the three did
not find any significant reduction in cardiovascular events due to CPAP use overall. Two of the three studies showed
that there was no significant reduction in cardiovascular events,
no matter if the participants were adherent to CPAP use or not. The other showed that there
was a significant reduction in cardiovascular events,
but only for the people who used their CPAP machine as prescribed. The meta-analysis took the
individual data from each of the three studies and combined
them all into one big group. This gave them an effectively
new set of numbers to crunch, totaling more than 4,000 people. And they found that when
comparing the groups as-is, CPAP did not seem to have a significant impact. But, when they isolated just
the participants who used their CPAP machine for at least 4 hours a night, they were able to find a significant reduction in the risk of cardiac events. It’s all in how you set up the numbers. Relationships can appear and disappear depending on how you look at your data, so it’s important to do your statistics properly and not just in a way that
shows you there’s an effect. Here’s the takeaway from all that: It is well-determined that CPAP
machines are highly efficacious in preventing your airways from
collapsing throughout the night. But those benefits can disappear in studies of people out there in the
real world, being forgetful and imperfect and not
flawlessly-doctor-order-following as people tend to do. But important question,
are there any alternatives? One treatment option that I haven’t mentioned yet, for reasons of dramatic tension, are oral devices that reposition your tongue and jaw to keep your airways open. They kinda look like a mouth guard
or a retainer – no tubes needed! It’s officially called oral
appliance therapy, or OAT, and while it may be less
efficacious than a CPAP machine at preventing breathing
obstruction throughout the night, it could be more effective, since patients are more likely
to be consistent with it. OAT is only meant for people with mild to moderate obstructive sleep apnea, but if you qualify and are having
trouble sticking with a CPAP machine, this may be a great thing
to ask your doctor about. Maintaining a CPAP machine regimen can be difficult for a lot of people. Studies suggest that only about 50% of people prescribed CPAP treatment are
using it consistently enough, and that number could be even lower for people with milder sleep apnea symptoms. But people who use OAT instead
of CPAP have been found to use their oral appliances for a
whopping 95% of their sleep time! To fully assess the benefits of switching to OAT, doctors and patients would need to
discuss whether the loss in efficacy is made up for by the increased
consistency in using oral appliances. This full-picture assessment
is why some scientists are advocating for considering effectiveness instead of just efficacy when
deciding on the best treatment. Another bonus is that while oral appliances may be initially more
expensive than a CPAP machine, you only need to replace them
every 5 years, whereas you may need to replace CPAP machine parts every 6 months. Analyses suggest that OAT matches the initial cost of a CPAP machine after just four months. In terms of health outcomes
beyond your beauty rest, some initial studies suggest that
oral appliance therapy is comparable to using a CPAP machine for
daytime sleepiness, blood pressure, and cardiovascular mortality rates. Y’know, to the extent that
we know that for CPAP either… It’s messy. One drawback is that the costs
and coverage of oral appliances can vary a lot, depending on the model you get, your insurance provider,
and what region you live in. Also, if you have severe sleep apnea, oral appliance therapy likely won’t work for you. Defer to your doctor on all this stuff. I am not a doctor. I’m not here
to sell you on any of this stuff. Talk to them. So, there you have it. The story of the CPAP machine is a complex one. Until researchers are able to
conduct more conclusive studies on CPAP and OAT, it’s hard to
make any sweeping recommendations or conclusions about whether they’re good or bad. We need higher quality, longer-term
studies to be able to really understand what symptoms can and can’t be fixed by different treatment options
for obstructive sleep apnea. But I’ll repeat what I said earlier – CPAP is still the gold standard,
being the best option we have, and sleep doctors still want you to use it. If OAT works better for some
people, awesome, sweet dreams. But do what your doctor says! And until researchers can hammer
out a clearer consensus on CPAP, slap that bad boy on and at least
try to get a good night’s rest. If you’re interested in learning
even more about the science of sleep and how to help yourself do a better job of it, you might like this video
on the mouth taping trend. Does that work? Ah, it– I don’t know! Head on over to find out, and thanks for watching.
