Who Refers Musculoskeletal Extremity Imaging Examinations to Radiologists?

The purpose of this study is to identify the specialty characteristics of providers referring musculoskeletal (MSK) extremity imaging examinations to radiologists, so as to better understand the drivers of MSK imaging utilization and potentially improve the appropriateness of such imaging examinations.

Data on provider referral for MSK extremity imaging services were extracted from the 2014 Medicare Referring Provider Utilization for Procedures public use file, which aggregates data on diagnostic procedures according to referring provider identities and service codes. MSK extremity imaging services were identified using Neiman Institute Types of Service codes. The referring provider specialty was identified from cross-linked Medicare provider characteristics files.

For 4,275,647 MSK extremity imaging examinations ordered, the most common specialties of the referring providers were orthopedic surgery (37.6% of ordered examinations), internal medicine (20.2%), family practice (14.8%), emergency medicine (7.9%), and rheumatology (5.7%). Orthopedic surgery was the referring specialty that most commonly ordered MSK extremity CT (33,465 ordered examinations; for all other specialties, < 2000 examinations), MRI (325,485 examinations; for all other specialities, < 20,000 examinations), and radiography (1,249,748 examinations; for all other specialities, < 850,000 examinations), whereas internal medicine was the referring specialty that most commonly ordered MSK extremity ultrasound examinations (8052 ordered examinations; for all other specialties, < 6000 examinations). Among the select specialties most relevant to MSK imaging, the most frequent referrers after orthopedic surgeons were rheumatologists, for radiography (236,057 ordered examinations) and ultrasound (2034 examinations), and podiatrists, for CT (1201 examinations) and MRI (19,159 examinations). The most commonly ordered individual MSK extremity imaging services were knee radiography, with 190,354 examinations ordered by orthopedic surgeons; hand radiography, with 66,167 examinations ordered by rheumatologists; foot radiography, with 137,042 examinations ordered by podiatrists; shoulder radiography, with 11,299 examinations ordered by sports medicine specialists; and hip radiography, with 9838 examinations ordered by physiatrists.

Referral patterns for MSK imaging vary considerably by provider specialty. Referral pattern insights may guide targeted efforts by radiologists to ensure the appropriateness of such examinations.