Awhile back Aidan Baron (@Aidan_Baron) tweeted, "If you can't explain the pre-test probability, then you don't get to pick up the ultrasound.. no stats-no scan."    This got me thinking about the way we approach testing in the pre-hospital setting. Are we performing EKG's, POC Labs, Ultrasound scans, and screens on patients just because we need to check off a box on our PCR, or do we truly believe the pre-test probably is high enough to justify the test?   My thought process had always been that this is a way of triaging your mental bandwidth, and that it was only applicable when seeing more than just one patient. A physician, PA, or NP could not physically perform every test on every person without complications and decreased attention to top tier priorities.   In this podcast Chip Lange from TOTAL EM, and I discuss if pre-test probability and risk stratification is applicable to EMS.   www.foamfrat.com