Association Between Practice Closure and Subsequent Subspecialization Among Affiliated Radiologists

To examine the association of practice closure with the likelihood that individual radiologists will subsequently practice as subspecialists given continued subspecialization and closure trends.

CMS data (2014-2022) were used to determine whether individual radiologists practiced as subspecialists and whether they were affiliated with a practice that closed. Radiologists with >50% of their workload in a single subspecialty were classified as subspecialists versus generalists. Differences between radiologists with and without a practice closure were assessed with χ² tests; unadjusted subspecialization rates were assessed by practice type, size, and urbanicity. Multivariable logistic regression was used to estimate whether radiologists who experienced a practice closure were more or less likely to practice as a subspecialist in the following year, controlling for radiologist and practice characteristics.

The study included 238,725 radiologist years. The year-over-year unadjusted increase in the share of radiologists practicing as subspecialists was 2.5 percentage points after a practice closure compared with 1.8 percentage points for those whose practice did not close. Adjusted for radiologist and practice characteristics, radiologists with a closure had 10% higher odds of practicing as a subspecialist in the following year (odds ratio, 1.10; 95% confidence interval, 1.03-1.17). More years of practice, larger practices, and multispecialty practices were significantly associated with increased subspecialization after a closure.

Radiologists who experienced practice closure were more likely to practice as subspecialists afterward. This increased likelihood is distinct from the overall temporal trend of increasing subspecialization among radiologists. Hence, practice closure may be associated with increased subspecialization beyond the general trend.