Conclusions
WELLS
In conclusion, in this study we developed a new pretest probability (PECSS) that is more comprehensive and accurate than the well established Wells score for PE diagnosis, and incorporated plasma level of D-Dimer with PECSS as a clinical instrument to rule out PE among suspected patients presenting to the emergency department. Both PECSS and PECSS + D-Dimer approaches showed excellent performances in reducing PE cases that were ruled out, and the advantages over Wells score and Wells + D-Dimer approaches were more pronounced among patients with severe PE, which would usually lead to worst prognosis and highest mortality. With PECSS and D-Dimer, PE diagnosis could be operated more efficiently without overuse of CTPA. Finally, all clinical predictors in PECSS are easy to obtain from medical records and routine blood tests, making PECSS a practical tool in emergency medical setting.