Also posted over at Paramedicine 101 (now at EMS Blogs ) and at Research Blogging . Go check out the excellent material at these sites. – This is adding to what I wrote yesterday about the continuing failure of Masimo’s RAD-57 . [1] The RAD-57 does not demonstrate any kind of acceptable sensitivity or specificity to be marketed as a mass screening device – and especially not to screen firefighters to go back to fighting fire. This is just more evidence that the RAD-57 does not accurately measure carboxyhemoglobin (COHb). Here is a report of an interesting complication of a mass delusion that seems to have been compounded by the use of the Masimo RAD-57 non-invasive CO monitor. CO (Carbon monOxide) is a significant cause of poisoning in the US, but not relevant in this case. The RAD-57 incorrectly identified CO poisoning in half a dozen people who do not appear to have had any exposure to CO. – Sociogenic illness is a rare but well-described phenomenon. It involves a constellation of physical signs and symptoms without an organic cause in a group of individuals with a common ‘‘exposure’’ (1–8). It often occurs in the setting of large gatherings such as schools or when large numbers of people are living or working in close proximity. [2] I wrote about a different example of mass delision a couple of weeks ago. [3] We underestimate our ability to delude ourselves, but we are great at self-delusion and we are most delusional in groups. No need for any objectivity. Just go with the feeling of a group.

Original Source of Mass sociogenic illness initially reported as carbon monoxide poisoning