WatchPat sleep study Question

[RobbyM684]

As a prior cpaper, I was surprised when my wife's recent sleep study did not include any airflow sensors. It is called a WATCHPAT. Are these accurate?

[dataq1]

Are these accurate?

Accuracy....Apparently it depends on what they are being compared with. PAT devices ( Peripheral Arterial Tonometry) do not measure AHI in the traditional sense, rather it infers respiratory disturbance (RD) from changes in the sympathetic system (nervous system) as detected by changes on the skin.

So, if the comparative measure is Apnea Hypopnea Index, then a recent (April 2022) journal article from Journal of Clinical Sleep Medicine*, asserts that the comparison is poor. In their words:

...clinically significant discordance between WatchPAT and PSG measurements of AHI, significant sleep apnea severity misclassification by PAT studies, and poor diagnostic test performance.

Percentage error (between the WatchPAT and gold standard (PSG) was calculated at 230% , (1400 participants in 17 different studies)

I suspect that the manufacturer of WatchPAT would disagree, but so far I've not come across any rebuttal.

*https://pubmed.ncbi.nlm.nih.gov/34879903/

(Does it seem that we are coming ever closer to the Star Trek Medical Tri-corder of Dr. "Bones" McCoy ?)

[Miss Emerita]

That's a sobering meta-analysis. I had been familiar only with this earlier, more encouraging, one:

https://pubmed.ncbi.nlm.nih.gov/24158564/

I'm especially concerned because as far as I know, the entire Kaiser health system uses WatchPAT as the test of choice.

[dataq1]

That's a sobering meta-analysis. I had been familiar only with this earlier, more encouraging, one:

https://pubmed.ncbi.nlm.nih.gov/24158564/

I'm especially concerned because as far as I know, the entire Kaiser health system uses WatchPAT as the test of choice.

Yes, a bit concerning..... but I haven't been able to see the whole article, so there may be more detail there.

As far as I can tell the WatchPAT, does NOT report a "AHI" as we are accustomed to, rather they report a value
called pAHI ( meaning it's a" PAT" derived AHI, and somehow "different" from a classical AHI ??)

No question the sleep study "cost" is cheaper, but I hope that's not what is driving the industry

[lazarus]

Is There a Downside to Home Sleep Testing?

For most people, the biggest risk of a home sleep apnea test is the potential for being misdiagnosed as not having obstructive sleep apnea when they actually have it, or as having a milder version than they actually do. For this reason, doctors often order an in-lab sleep study when a home sleep study comes back negative.

https://www.sleepfoundation.org/sleep-s ... leep-study

[lynninnj]

Are these accurate?

Accuracy....Apparently it depends on what they are being compared with. PAT devices ( Peripheral Arterial Tonometry) do not measure AHI in the traditional sense, rather it infers respiratory disturbance (RD) from changes in the sympathetic system (nervous system) as detected by changes on the skin.

So, if the comparative measure is Apnea Hypopnea Index, then a recent (April 2022) journal article from Journal of Clinical Sleep Medicine*, asserts that the comparison is poor. In their words:

...clinically significant discordance between WatchPAT and PSG measurements of AHI, significant sleep apnea severity misclassification by PAT studies, and poor diagnostic test performance.

Percentage error (between the WatchPAT and gold standard (PSG) was calculated at 230% , (1400 participants in 17 different studies)

I suspect that the manufacturer of WatchPAT would disagree, but so far I've not come across any rebuttal.

*https://pubmed.ncbi.nlm.nih.gov/34879903/

(Does it seem that we are coming ever closer to the Star Trek Medical Tri-corder of Dr. "Bones" McCoy ?)

This study was cited by this study which came later (supposedly) https://pubmed.ncbi.nlm.nih.gov/36036338/ which says: Results: In this review, 18 studies were included for a total of 1049 patients, aged 8 to 70 years old, with 74 of these being pediatric patients. In most studies, patients completed an overnight PSG and simultaneously wore WatchPAT in a sleep laboratory, while others compared the results obtained on two different nights. Both protocols showed good results in terms of AHI, ODI, RDI, and SO2. Moreover, some studies calculated the sensitivity and specificity of the WP ranging from 87 to 96% and from 66 to 80%, respectively. Excellent results were found also in pediatric patients.

Conclusion: The WP represents an effective and convenient tool for OSA diagnosis compared to standard reference systems.

That said-the problem *I* have when i see metaanalysis is that it helps to be able to see which research is being cited so one can examine the source. (At least in my own field, which this is not.) I am not saying it is poorly done, I am just saying that you need to look further. I dont see which studies it cites and whether it cites the one posted by Miss Emeritus from 2013. The one I cited above is also claims to be a data analysis and it compares directly a sleep study done with PSG and Watchpat....a direct comparison done at the same time.

So I will say again, so nobody misunderstands (and we will know the careful and honest readers based on their reaction to the statements above) this is NOT my field, just my general*** criticisms of meta analysis type research.

And now I understand why you wanted to know if this journal was a reliable source of information. I do not know whether this publication trumps something like JAMA Otolaryngol Head Neck Surg (I put my money on JAMA above most others, most of the time.) JMHO of course.

Edit: And don't forget, an abstract isn't worth much by comparison to a full text article.

[lazarus]

3. We recommend that if a single home sleep apnea test is negative, inconclusive, or technically inadequate, polysomnography be performed for the diagnosis of OSA. (STRONG)
4. We recommend that polysomnography, rather than home sleep apnea testing, be used for the diagnosis of OSA in patients with significant cardiorespiratory disease, potential respiratory muscle weakness due to neuromuscular condition, awake hypoventilation or suspicion of sleep related hypoventilation, chronic opioid medication use, history of stroke or severe insomnia. (STRONG)

https://aasm.org/aasm-releases-position ... a-testing/

[ChicagoGranny]

As a prior cpaper, I was surprised when my wife's recent sleep study did not include any airflow sensors. It is called a WATCHPAT. Are these accurate?

WatchPAT is an excellent innovation that saves time, money, and other resources. If your wife gets a positive diagnosis, she has a positive diagnosis (lol) and can get a prescription for CPAP.

If she gets a negative diagnosis, there should be a discussion with her doctor. Based on her symptoms, it may be necessary to undergo an in-lab study.

[RobbyM684]

I probably left an incorrect impression in my first post. I am a current user of cpap, my reference to "prior" was that I that I had taken a sleep study previously, some years ago.

The intent of my question had to do with the comparison of the in-lab study (where they measured EVERYTHING) to come to the conclusion that I had mild to moderate sleep apnea, and what my wife just had (and apparently is becoming the popular method where only the skin (tone/color/nerves) and position are being measured.

[ChicagoGranny]

where only the skin (tone/color/nerves) and position are being measured.

Actually, WatchPAT measures peripheral arterial tone, heart rate, oximetry, actigraphy, body position, snoring, and chest motion.

my wife

What were the results of her study?

[lazarus]

I probably left an incorrect impression in my first post. I am a current user of cpap, my reference to "prior" was that I that I had taken a sleep study previously, some years ago.

The intent of my question had to do with the comparison of the in-lab study (where they measured EVERYTHING) to come to the conclusion that I had mild to moderate sleep apnea, and what my wife just had (and apparently is becoming the popular method where only the skin (tone/color/nerves) and position are being measured.

And the answer for that comparison is this:

1. An in-lab study can (a) indicate that you are likely to benefit from PAP. It can ALSO (b) indicate that you are unlikely to benefit from PAP. Furthermore, it can (c) screen for related sleep disorders.

2. A home study can (a) indicate you are likely to benefit from PAP. However, it is UNABLE to indicate that you are unlikely to benefit from PAP. It is also unable to screen for or rule out some related sleep disorders.

Home studies are great when the supervising sleep doc understands the limitation of them and uses them to get a patient quickly and conveniently to what appears to be the most urgently needed treatment.

However, they are too often misused as a way for payors to point to their meaningless negative results as an unscientific, nonmedical excuse for refusing proper screening and treatment for people with significant undiagnosed sleep issues.

[ChicagoGranny]

Don't forget, the planet does not have enough resources to build and staff sleep labs for one billion sleep apnea sufferers. Sleep labs should only be used for exceptional cases.

[Jlfinkels]

Don't forget, the planet does not have enough resources to build and staff sleep labs for one billion sleep apnea sufferers. Sleep labs should only be used for exceptional cases.

I thought that was a bit hyperbolic, but a quick read of CDC data may be used to interpolate that 1B number as those who are diagnosed and undiagnosed for sleep disorders. It is an amazing number that 1 out of 8 has sleep issues. Not all necessarily sleep apnea as the CDC questionnaire was about good sleep, but still a big number.

[ChicagoGranny]

Don't forget, the planet does not have enough resources to build and staff sleep labs for one billion sleep apnea sufferers. Sleep labs should only be used for exceptional cases.

I thought that was a bit hyperbolic, but a quick read of CDC data may be used to interpolate that 1B number as those who are diagnosed and undiagnosed for sleep disorders. It is an amazing number that 1 out of 8 has sleep issues. Not all necessarily sleep apnea as the CDC questionnaire was about good sleep, but still a big number.

Sleep apnea - 1.361 billion worldwide under the age of 70. Now add those over 70.

The Lancet

Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis

Using AASM 2012 diagnostic criteria and AHI threshold values of five or more events per h and 15 or more events per h, we estimated that 936 million (95% CI 903–970) adults aged 30–69 years (men and women) have mild to severe obstructive sleep apnoea and 425 million (399–450) adults aged 30–69 years have moderate to severe obstructive sleep apnoea globally.

https://www.thelancet.com/journals/lanr ... 5/fulltext

I guess they'll just let us 70 and over die.

[RobbyM684]

where only the skin (tone/color/nerves) and position are being measured.

Actually, WatchPAT measures peripheral arterial tone, heart rate, oximetry, actigraphy, body position, snoring, and chest motion.

my wife

What were the results of her study?

First the easy question: what were the results? She has yet to get any results (test was done Dec 10)

So I had to look up actigraphy, (are we talking about the same thing? ) ' actigraphy measures gross motor activity and light for a week or so to determine cycles of activity' and used to evaluate interruptions of circadian rhythm'

By "arterial tone" , do you mean the responsiveness of the arteries to sympathetic nervous system? (fight or flight type reactions?)