National specialty trends in billable diagnostic ultrasound in the ED: analysis of Medicare claims data

Objective: To assess recent national specialty trends in the use of diagnostic ultrasound (US) services in the Emergency Department (ED) setting.

Methods: We searched aggregated 1998-2012 Medicare Part B Master Files for ED diagnostic US studies, excluding cardiac and ophthalmic examinations. Studies were classified by body part and interpreting specialty. Subsequent analysis was performed for higher-volume services rendered by emergency physicians for which discrete codes were present longitudinally for complete vs limited examinations. National trends were analyzed.

Results: From 1998 to 2012, paid ED US studies interpreted by radiologists, emergency physicians, and all other physicians increased by 332% (from 221,712 to 735,858 examinations), 4454% (from 561 to 24,992), and 251% (from 26,961 to 67,787), respectively. The fraction of ED US examinations interpreted remained around 90% for radiologists, increased from 0.2% to 3% for emergency physicians, and decreased from 11% to 8% for other physicians. The fraction of complete abdominal and complete retroperitoneal studies interpreted by emergency physicians remained less than 1% from 1998 through 2012. However, emergency physicians experienced disproportionate growth in limited examinations (from 1% to 9% for abdominal studies and from <1% to 20% for retroperitoneal studies). Likewise, the fraction of (typically targeted) chest studies interpreted by emergency physicians increased from less than 1% to 63%.

Conclusion: From 1998 to 2012, there was substantial growth in ED US studies for Medicare beneficiaries interpreted by radiologists and emergency physicians alike. For more commonly performed services distinguishable as complete vs limited in nature, growth in services by emergency physicians was most dramatic for less complex services.