Pulmonary embolism incidence is increasing with use of spiral computed tomography.

BACKGROUND: Pulmonary embolism causes significant morbidity in hospitalized patients, yet few studies have explored the impact of spiral computed tomography (CT) scanning on diagnosis and clinical outcome.

METHODS: Incidence rates of pulmonary embolism, chest and spiral CT rates, D-dimer assay, anticoagulation, and in-hospital mortality were assessed on statewide pulmonary embolism discharge data (1997-2001) from the Pennsylvania Health Care Cost Containment Council.

RESULTS: The incidence of pulmonary embolism increased from 47 to 63 per 100,000 patients from 1997 to 2001 (mean of 0.004% per year, P < .001). Mean pulmonary embolism incidence rates were higher for African American patients (0.031% per year higher than for white patients), patients aged 70 years or more (0.007% higher than for patients aged<70 years), and female patients (0.013% higher than for male patients) (all P < .001). Concomitantly, the proportion undergoing CT (including spiral) scans increased from 23.23% to 45.18% (odds ratio=1.30; P<.001), controlling for age, gender, race, and cancer, whereas rates for other procedures remained unchanged. By comparing 1999 and before with 2000 and after, there was a significant decrease in the 2 highest Atlas Severity of Illness categories (49.4%-37.7%) and a significant increase in the 3 lowest categories (50.6%-62.3%; P < .001). The risk of in-hospital deaths among patients with pulmonary embolism decreased in this period from 12.8% to 11.1% (P < .001).

CONCLUSION: The incidence of pulmonary embolism is increasing with the increasing use of spiral CT scans, with a lower severity of illness and lower mortality, suggesting the increase is due to earlier diagnosis.