Frequency of use of imaging tests in the diagnosis of pulmonary embolism: effects of physician specialty, patient characteristics, and region.

OBJECTIVE: The purpose of this study was to ascertain whether clinical practice in diagnosing pulmonary embolism is consistent with recommendations in the literature and to explore variations in practice across site of care (e.g., emergency department), physician and patient characteristics, and geographic location. MATERIALS AND METHODS: Medicare 5% research identifiable files were analyzed. The cases of patients with emergency department visits or inpatient stays for a diagnosis of pulmonary embolism or for symptoms related to pulmonary embolism (shortness of breath, chest pain, and syncope) were identified. We determined the number of patients who underwent each type of relevant imaging test and evaluated variations in the first non-chest-radiographic test by site of care and treating physician specialty. Using logistic regression, we studied variations in the use of common imaging tests, exploring variations associated with patient characteristics, physician specialty, site of care, and geographic location. RESULTS: For patients in whom pulmonary embolism might have been suspected, the most common tests were echocardiography (26% of the patients), CT or CT angiography of the chest (11%), cardiac perfusion study (6.9%), and duplex ultrasound (7.3%). For patients with an inpatient diagnosis of pulmonary embolism, the most common tests were chest CT or CT angiography (49%), duplex ultrasound (18%), echocardiography (10.9%), and ventilation-perfusion scintigraphy (10.9%). For patients for whom pulmonary embolism might have been suspected, many large variations were found in practice patterns among physician specialties and geographic locations. There were fewer variations among patients with the inpatient diagnosis of pulmonary embolism. CONCLUSION: Physician practice in the diagnosis of pulmonary embolism is broadly consistent with recommendations. However, variations by physician specialty and geographic location may be evidence of inappropriate imaging.

The actual role of CT and ventilation-perfusion scanning in workup for suspected pulmonary embolism: evidence from hospitals.

OBJECTIVE: Over the past two decades, CT has been found valuable in the diagnosis of pulmonary embolism (PE). We sought to ascertain the relative roles of CT and ventilation-perfusion (V/Q) scanning, the previously preferred technique, in the diagnosis of PE in recent practice and whether there is variation among hospital types. MATERIALS AND METHODS: Using the Medicare anonymized 5% of beneficiaries complete claims file for 2005, we studied the use of relevant CT and V/Q scanning in the evaluation of patients with a diagnosis of PE and of patients with symptoms that might have been due to PE (chest pain, syncope, difficulty breathing). In 2008, we surveyed the radiology departments of Pennsylvania hospitals about the use of CT and V/Q scanning for PE, service availability hours, and what equipment was used. RESULTS: In all data, we found that CT was used approximately six times as frequently as V/Q scanning. In the Medicare data, only small differences in frequency of use of CT and V/Q scanning were associated with hospital characteristics. Academic hospitals did not differ in a major way from other hospitals, nor did small or rural hospitals. In the survey, 97% of radiology departments reported that CT was available for evaluation of PE 24 hours a day 7 days a week. Ninety-three percent of departments reported V/Q scanning was available at some times; 77% reported V/Q available at all times. CONCLUSION: CT was a fully disseminated and dominant technique for the diagnosis of PE by 2005, and it was readily available at small and rural hospitals. The lack of availability of off-hours V/Q scanning at a substantial fraction of hospitals may be a problem for patients with contraindications to CT.