A Claims-Based Method for Identification and Characterization of Practicing Interventional Radiologists

Purpose Interventional radiologists (IRs) are inconsistently defined in health services research and underrepresented by specialty designation in claims data. This work proposes a research method for identifying ‘Practicing IRs’ using two national claims datasets. Materials and Methods 2015-2019 100% Medicare Part B data and 2015-2019 private insurance claims from Optum’s Clinformatics® Data Mart (CDM) Database were used to rank-order radiologists’ IR-related work as a percent of total-billed work Relative Value Units (wRVUs). Characteristics were analyzed at various threshold percentages. External validation used Medicare self-designated specialty with Society of Interventional Radiology membership records; Youden’s Index evaluated sensitivity and specificity. Multivariate logistic regression assessed Practicing IR characteristics. Results In Medicare data, above a 10% IR-work threshold, only 23.8% of selected Practicing IRs were designated as IRs in the Medicare data; above 50% and 90% thresholds, this percentage increased to 42.0% and 47.5%, respectively. The average percentage of IR-related work among Practicing IRs was 45% , 84% and 96% of total wRVUs for the 10%, 50% and 90% thresholds, respectively. At these thresholds, the CDM Practicing IRs included 21.2%, 35.2% and 38.4% designated IRs and E/M comprised relatively more total wRVUs. Practicing IRs were more likely to be male, metropolitan, and earlier in their careers than other radiologists, at all thresholds. Conclusion Most radiologists performing IR-related work are designated in claims data as DRs, indicating insufficiency of specialty designation for IR identification. The proposed method to identify Practicing IRs by percent IR-related work effort could improve generalizability and comparability across claims-based IR studies.