Non-clinical Drivers of Variation in Preoperative MRI Utilization for Breast Cancer.

backgroundPreoperative magnetic resonance imaging (MRI) utilization in breast cancer treatment has increased significantly over the past 2 decades, but its use continues to have interprovider variability and disputed clinical indications.

objectiveThe aim of this study was to evaluate non-clinical factors associated with preoperative breast MRI utilization.

methodsThis study utilized TRICARE claims data from 2006 to 2015. TRICARE provides health benefits for active duty service members, retirees, and their dependents at both military (direct care with salaried physicians) and civilian (purchased care under fee-for-service structure) facilities. We studied patients aged 25-64 years with a breast cancer diagnosis who had undergone mammogram/ultrasound (MMG/US) alone or with subsequent breast MRI prior to surgery. Facility characteristics included urban-rural location according to the National Center for Health Statistics classification. Adjusted multivariable logistic regression tests were used to identify independent factors associated with preoperative breast MRI utilization.

resultsOf the 25,392 identified patients, 64.7% (n = 16,428) received preoperative MMG/US alone, while 35.3% (n = 8964) underwent additional MRI. Younger age, Charlson Comorbidity Index score ≥ 2, active duty or retired beneficiary category, officer rank (surrogate for socioeconomic status), Air Force service branch, metropolitan location, and purchased care were associated with an increased likelihood of preoperative MRI utilization. Non-metropolitan location and Navy service branch were associated with decreased MRI use.

conclusionAfter controlling for expected clinical risk factors, patients were more likely to receive additional MRI when treated at metropolitan facilities or through the fee-for-service system. Both associations may point toward non-clinical incentives to perform MRI in the treatment of breast cancer.