The pulmonary embolism rule-out criteria (PERC) was created to reduce testing in patients who have a very low probability of PE (i.e. prevalence of <1.8%) in which further testing would not be necessary.  There have been many observational trials published on this score but until now there has not been a prospective randomized clinical trial (The PROPER Trial). #Diagnosis #EM #IM #PERC #Rule #Criteria #Pulmonary #Embolism #PulmonaryEmbolism #RebelEM