According to a new study published in the JAMA Intern Medicine, among physicians who ordered a greater number of CTPA scans, a statistically significant decrease in the proportion of positive results. The association may reflect a fundamental relationship between individual physician overutilization and decreasing diagnostic yield and is deserving of greater attention.

Pulmonary embolism (PE) can be life-threatening and, when suspected, is usually investigated by computed tomographic pulmonary angiogram (CTPA). Concerns related to overutilization and harmful ionizing radiation has identified CTPA as an area in need of resource stewardship. The purpose of this study was to explore interphysician variability in CTPA diagnostic yield and to identify any associated physician characteristics that could inform an intervention to reduce overuse in our institution.

Researchers retrospectively reviewed all CTPAs at an academic teaching hospital in Montreal, Quebec, Canada. A total of 1394 examinations ordered by 182 physicians were included, of which 199 (14.3%) were positive and 1195 (85.7%) were negative. A multivariable logistic regression analysis was performed to explore whether physician speciality, years in practice, physician sex, or total numbers of studies ordered per physician were associated with CTPA diagnostic yield.

According to our analysis using a generalized estimating equation (GEE) logistic regression, the odds of a positive CTPA decreased as the total number of scans ordered per physician increased. For each additional 10 studies ordered the odds of a positive result decreased. Increasing patient age was associated with a higher diagnostic yield. Physician years of experience, physician sex, and studies originating from the emergency department (ER) did not show a statistically significant association.

The institutional yield of positive CTPA was 14.3%, which is similar to prior reported studies. However, closer inspection demonstrated that there was substantial interphysician variability, with individual positivity rates ranging between 0% to 33.3%. The study suggests that individual demographic features, such as speciality and professional experience are not significantly associated with diagnostic yield.

However, physicians who ordered a greater volume of scans compared with their peers had a markedly reduced diagnostic yield. Limitations of the study included its retrospective design and the inadequate charting of parameters, which precluded the derivation of a preexamination clinical probability score. In addition, owing to limitations in data collection, we were unable to determine the denominator of patients presenting with PE-related symptoms examined by each physician.

Among physicians who ordered a greater number of CTPA scans, the team observed a statistically significant decrease in the proportion of positive results. The association may reflect a fundamental relationship between individual physician overutilization and decreasing diagnostic yield and is deserving of greater attention. Peer-relative rates of utilization are easily quantified from electronic databases and can identify physicians most likely to benefit from individual performance feedback and decision support tools.

Based on the findings, the researchers have designed automated yield monitoring and feedback, with the aim of closing the gap between individual physician performances in the institution. The study might translate to a substantial reduction in unnecessary CTPA scans along with the associated complications that may occur owing to unnecessary radiation, overdiagnosis, and overtreatment.