Don't just do something – stand there.
Low risk geneva can't risk stratify to allow PERC. The resultant pretest is too high for perc to reduce below the testing threshold. This has been studied. Gestalt or Wells for PERC.
lowest Geneva gets you to 8%, no? isn't that low enough for PERC?the PERC meta analysis from Annals gets a LR- from 0.13-0.23; plotting the 0.23 on a Fagan nomogram to get a post test of ~1.6-1.8, gets you get a max pretest of 8%
Nope search for the paper, also discussed somewhere on emcrit site. Turns out Perc did not cut it with Geneva. Why? B/c in Europe they dom't start a PE workup or get referred pts like this unless sicker. That is the prob. with US PE studies–dilution by the well. If you include tons of pts who have no business needing a workup, they all fill up the low risk cohort.
updated, thanks for the input