Objective: To evaluate the added value of CT pulmonary angiography (CTPA) in patients who have undergone this procedure for suspected pulmonary embolism (PE). We evaluated this added value by investigating both the rate of pulmonary embolism ascertained and the rate of CTPA without abnormal findings, each in relationship to various characteristics of the patient and referring individuals.
Design: Diagnostic cross sectional research
Method: Data on all patients 18 years and older who underwent CTPA from November 2008 to February 2011 at the Leiden University Medical Centre because of suspected pulmonary embolism were entered into a database. We collected information on the patient, referring individual, reason for referral and the outcome of the CTPA, and described the rate of positive CTPA for various subgroups. In addition, we described the rate of CTPA's within these groups in which no abnormalities were demonstrable.
Results: After exclusion of patients with a PE found by chance (n = 28), the total patient population was comprised of 1344 patients. In 19.1% of these patients, PE was confirmed by CTPA. This percentage was lower in the female population (16.9%; 95% CI: 14.4-19.6), and in outpatients (10.9%; 95% CI: 5.5-16.3). In 42% of CTPAs in the group of patients younger than 40 years, no abnormalities were found
Conclusion: The CTPA yield could be improved in women and younger patients. This would increase cost-effectiveness and reduce unnecessary side effects. For this reason, further investigation into the motives of doctors referring young people, women and outpatients would be helpful in preventing the overuse of this diagnostic tool.