Imaging use among employed and self-employed urologists

Compared to physicians paid on salary (ie employed), those who own their practice (ie self-employed) derive financial benefit from providing more care. Whether the volume based incentives of ownership influence physician use of other ancillary services, like diagnostic imaging, remains unknown. We explored this possibility among urologists.

We used data from the National Ambulatory Medical Care Survey (2006 to 2007) to identify outpatient urology visits. We determined whether the urologist who was responsible for the encounter was employed or self-employed. We calculated the proportion of visits at which imaging was ordered, and we evaluated for a difference between visits directed by employed vs self-employed urologists. We used multivariable logistic regression to measure the relationship between urologist employment status and imaging use, adjusting for patient, provider and practice level characteristics.

More than 1 in 5 urology visits resulted in imaging. While imaging use did not vary by measurable patient or practice level characteristics, self-employed urologists ordered imaging more often than employed urologists (24.2% vs 13.2%, respectively, p<0.001). In fact, the odds of a patient receiving imaging were almost 2-fold greater if seen by a self-employed urologist (OR 1.84, 95% CI 1.18-2.87). On stratified analysis an independent association between employment status and imaging use was observed for urolithiasis (OR 4.76, 95% CI 1.30-17.4) and hematuria visits (OR 5.52, 95% CI 1.23-24.8).

Compared with employed urologists, those who are self-employed have more resource intense practice styles with respect to imaging use.