03-16-2020, 08:05 PM
RE: Good AHI with CPAP - is an oxygen tracker worth it?
While I just ordered the Contec CMS 50F, I have significant concerns about its precision/accuracy and its test/retest reliability. Has anyone who has one been able to wear it at the same time an "official" sleep study has been done to shed some light on this?
In doing some preliminary research on things I found these PubMed articles which support being concerned about an $80 device perhaps being not much more than a toy, and if it gives false positives and false negatives this could lead too poor decision making by users. I plan to proceed with caution taking the results with a grain of salt. I'd say one of my larger concerns is that if a $1,000 device presumed accurate would say give a reading of 87 and say the Contec gives a reading of 85 ... at another part of the night or on a different night would the Contec again read 85? Having a consistent (proportional) error (consistently over or under) over would have some usefulness as one could at least see if there is a trend in your data. Unfortunately I expect that the likely error direction and magnitude is somewhat random.
https://www.ncbi.nlm.nih.gov/pubmed/27089002
While the above article summary is somewhat encouraging: "Two of the pulse oximeters tested (Contec CMS50DL and Beijing Choice C20) demonstrated ARMS of <3% at SaO2 between 70% and 100%, thereby meeting International Organization for Standardization (ISO) criteria for accuracy." I don't know whether they tested multiple devices from the same Mfg,. and whether all of them were similarly accurate. given at that this price point that quality control is probably not great, caution is still warranted regarding the data.
This 2nd article summary looked at accuracy of devices (and I believe that all of those tested were >$800 in cost) and their accuracy was impaired (>3%) if the device was moving during measurement. If one is a restless sleeper this should be taken into consideration in reviewing data.
https://www.ncbi.nlm.nih.gov/pubmed/29200008
If you read some of the more technical article summaries noted in right column for each of the above I realized that measuring things ain't that easy.
NOTE I am not a doctor, or a researcher and while I believe I have conveyed some of the key info in the above summaries, you need to read and decide for yourself (especially since the accuracy of data might impact your health or actual life expectancy).
There is a product review in the review forum of someone who got the Resmed oximeter. Perhaps if they read this and are willing to have someone loan them their Contec CMS 50F we might get our own internal test data by one person checking one Contec for accuracy.
Eager to hear what others on the forum have discovered and researched.
In doing some preliminary research on things I found these PubMed articles which support being concerned about an $80 device perhaps being not much more than a toy, and if it gives false positives and false negatives this could lead too poor decision making by users. I plan to proceed with caution taking the results with a grain of salt. I'd say one of my larger concerns is that if a $1,000 device presumed accurate would say give a reading of 87 and say the Contec gives a reading of 85 ... at another part of the night or on a different night would the Contec again read 85? Having a consistent (proportional) error (consistently over or under) over would have some usefulness as one could at least see if there is a trend in your data. Unfortunately I expect that the likely error direction and magnitude is somewhat random.
https://www.ncbi.nlm.nih.gov/pubmed/27089002
While the above article summary is somewhat encouraging: "Two of the pulse oximeters tested (Contec CMS50DL and Beijing Choice C20) demonstrated ARMS of <3% at SaO2 between 70% and 100%, thereby meeting International Organization for Standardization (ISO) criteria for accuracy." I don't know whether they tested multiple devices from the same Mfg,. and whether all of them were similarly accurate. given at that this price point that quality control is probably not great, caution is still warranted regarding the data.
This 2nd article summary looked at accuracy of devices (and I believe that all of those tested were >$800 in cost) and their accuracy was impaired (>3%) if the device was moving during measurement. If one is a restless sleeper this should be taken into consideration in reviewing data.
https://www.ncbi.nlm.nih.gov/pubmed/29200008
If you read some of the more technical article summaries noted in right column for each of the above I realized that measuring things ain't that easy.
NOTE I am not a doctor, or a researcher and while I believe I have conveyed some of the key info in the above summaries, you need to read and decide for yourself (especially since the accuracy of data might impact your health or actual life expectancy).
There is a product review in the review forum of someone who got the Resmed oximeter. Perhaps if they read this and are willing to have someone loan them their Contec CMS 50F we might get our own internal test data by one person checking one Contec for accuracy.
Eager to hear what others on the forum have discovered and researched.
