Increasing Subspecialization of the National Radiologist Workforce

The aim of this study was to assess recent trends in the generalist versus subspecialist composition of the national radiologist workforce.

Practicing radiologists were identified using 2012 to 2017 CMS Physician and Other Supplier Public Use Files. Work relative value units associated with radiologists' billed claims were mapped to subspecialties using the Neiman Imaging Types of Service to classify radiologists as subspecialists when exceeding a 50% work effort in a given subspecialty and as generalists otherwise. Additional practice characteristics were obtained from CMS Physician Compare. Chi-square statistics were computed.

The percentage of radiologists practicing as subspecialists increased from 37.1% in 2012 and 2013 to 38.8% in 2014, 41.0% in 2015, 43.9% in 2016, and 44.6% in 2017. By subspecialty, 2012 to 2017 workforce changes were as follows: breast, +3.7%; abdominal, +2.4%; neuroradiology, +1.8%; musculoskeletal, +0.8%; cardiothoracic, +0.2%; nuclear, -0.2%; and interventional, -1.2%. Increased subspecialization overall was consistently observed (P < .05) across cohorts defined by gender, years in practice, practice size, and academic status. The degree of increasing subspecialization was greatest for female (+12.1%) and earlier career (+10.2% for those in practice <10 years) radiologists and those in larger groups (+7.2% for ≥100 members). Subspecialization increased in 45 states, and state-level increased subspecialization correlated weakly with population density (r = +0.248).

In recent years, the national radiologist workforce has become increasingly subspecialized, particularly related to shifts toward breast imaging, abdominal imaging, and neuroradiology. Although growing subspecialization may advance more sophisticated imaging care, a diminishing supply of generalists could affect patient access and potentially separate radiologists across workforce sectors.