(26) Osteoarthritis Imaging Patterns in US Clinical Practice

Publication Number: 700

Background: In the United States (US), the use of imaging to diagnose and monitor osteoarthritis (OA) patients in clinical practice is not well characterized, and few recommendations are provided in clinical guidelines. Characterization of imaging (x-ray, magnetic resonance imaging (MRI), and computerized tomography (CT)) is important to understand its utility for assessing OA progression.

Objectives: To estimate the frequency of imaging for diagnosis or monitoring of patients with knee and/or hip OA in US clinical settings, overall, and by patient and physician characteristics.

Methods: This descriptive cross-sectional study used data from the 2020 US Adelphi Disease Specific Programme for OA, which surveyed physicians who made treatment decisions for ≥ 10 OA patients per month. Validated statistical survey methods have been published (Anderson 2008). Rheumatologists (n=35), orthopedists (n=27), pain specialists (n=14), and primary care physicians (PCPs) (n=50) were included. Surveyed physicians completed a record form on 10-12 consecutive OA patients ≥18 years old. Analyses were limited to patients diagnosed with hip and/or knee OA.

Patient characteristics were described overall, and by joint type. Descriptive statistics (e.g., mean, proportion) were used to summarize frequency of imaging overall, and by joint type and current pain level. Results were also stratified by physician specialty and insurance type.

Results: The study included 1120 patients with knee (61.6%), hip (19.7%), and both knee/hip (18.7%) OA. Mean age was 65.1 years, and 46.5% were male. Patients were primarily Caucasian (71.8%) and African American (14.4%), with the majority covered by Medicare (50.5%) or commercial insurance (37.2%). Characteristics were similar by joint type.

To diagnose OA, 91.3% of patients underwent x-ray, 27.0% MRI, and 5.9% no imaging. Imaging for monitoring was less frequent, with 69.3% undergoing x-ray and 12.9% an MRI to monitor OA in the past 12 months. CT scans were infrequent for diagnosis and monitoring ( < 1% of patients). Among patients imaged for monitoring, reasons included identifying worsening (69.9%) or new (30.5%) symptoms, or routine check-up (34.8%). The proportion of patients undergoing x-ray monitoring increased by pain severity (57% mild, 73% moderate, 81% severe). Among patients with moderate/severe pain, the proportion of patients undergoing x-ray monitoring was highest among orthopedists (orthopedist 85.9%, pain specialist 76.4%, PCP 74.3%, rheumatologist 70.3%).

Conclusions: In this sample of US patients, imaging was widely used to diagnose OA. Imaging was used to a lesser extent to monitor OA, with frequency varying by pain level and physician specialty.