Changing practice patterns in the workup of pulmonary embolism

Study objective: While the 'gold standard' for diagnosis of pulmonary embolism remains selective pulmonary angiography and its sensitivity and specificity are very high, it is not frequently used. The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) clinical trial results confirmed the low mortality and morbidity of pulmonary angiogram and the need for further evaluation of patients with 'low' and 'intermediate' probability ventilation/perfusion scans. We wanted to determine whether physician behavior changed from 1988 to 1991. Design: Retrospective review of inpatients having a ventilation/perfusion scan for suspected pulmonary embolism. The official reading of the ventilation/perfusion scans, venous leg sonograms with Doppler, contrast leg venograms, and pulmonary angiograms were recorded as well as the final diagnosis and treatment. Setting: A large city hospital-The New York Hospital-Cornell Medical Center, New York. Patients: All inpatients who had a ventilation perfusion scan in 1988 and all inpatients who had the procedure in 1991. Intervention: None. Results: The percentages of patients in each ventilation/perfusion scan category were similar in 1988 and 1991 as was the percentage of those who underwent anticoagulation therapy. Significantly more sonograms, however, were performed in 1991 along with fewer angiograms and venograms without any significant change in the overall cost. Conclusions: In 1991, additional diagnostic tests were performed after a low or intermediate ventilation/perfusion scan, but the percentage of patients who underwent anticoagulation did not change from 1988. This suggests that better diagnostic screening approaches with more explicit guidelines need to be developed that take into account the local disease prevalence and hospital diagnostic and practice patterns.