Use of Neuroimaging for Patients With Dizziness Who Present to Outpatient Clinics vs Emergency Departments in the US

Importance: Overuse of costly neuroimaging technology is associated with low-value care for the prevalent symptom of dizziness. Although quality improvement initiatives have focused on the overuse of computed tomography (CT) scans in emergency departments (EDs), most patients with dizziness present to outpatient clinics. To inform practice and policy, a comprehensive understanding of the uses and costs of neuroimaging across settings and episodes of care is needed. Objective: To characterize neuroimaging use, timing, and spending as well as factors associated with imaging acquisition within 6 months of presentation for dizziness in outpatient vs ED settings. Design, Setting, and Participants: This cross-sectional study of commercial and Medicare Advantage claims for 805 454 adults (≥18 years of age) with new diagnoses of dizziness was conducted from January 1, 2006, through December 31, 2015. Data were analyzed from October 1, 2020, to September 30, 2021. Main Outcomes and Measures: Use of neuroimaging (CT scan, magnetic resonance imaging MRI, angiography, and ultrasonography) and total spending on neuroimaging were measured. Kaplan-Meier analysis was performed. The associations of neuroimaging with setting, sociodemographic characteristics, and clinicians were estimated with multivariable analyses. Results: A total of 805 454 individuals with dizziness (502 055 women 62%; median age, 52 years range, 18-87 years) were included in this study; 156 969 (20%) underwent neuroimaging within 6 months of presentation (65 738 of 185 338 36% presented to EDs and 91 231 of 620 116 15% presented to outpatient clinics). The median time to neuroimaging was 0 days (95% CI, 0-2 days) after ED presentation and 10 days (95% CI, 9-10 days) after outpatient presentation. Neuroimaging was independently associated with advanced age, comorbidity, race and ethnicity, ED presentation, and outpatient clinician specialty. Across sites, a head CT scan was the most used test on presentation date (92% of tests 46 852 of 51 022). Within 6 months of presentation, a head CT scan was the most used test (47% of all tests 177 949 of 376 149), followed by brain MRI (25% 93 130 of 376 149), cerebrovascular ultrasonography (15% 56 175 of 376 149), and magnetic resonance angiography (9% 34 026 of 376 149). Of 88 646 047. 03 in total neuroimaging spending, MRI accounted for 70% (61 730 251. 95), CT scans for 19% (16 910 506. 24), and ultrasonography for 11% (10 005 288. 84). Per-test median spending ranged from 68. 97 (CT scan of the head) to 319. 63 (MRI of the brain) among commercially insured individuals and 43. 21 (CT scan of the head) to 362. 02 (MRI of the orbit, face, and neck) among Medicare Advantage beneficiaries. Conclusions and Relevance: The findings of this cross-sectional study suggest that use of neuroimaging for dizziness is prevalent across settings. Interventions to optimize the use of neuroimaging must occur early in the patient care journey to discourage guideline-discordant use of CT scans, advocate for judicious MRI use (particularly in ambulatory settings), and account for the effects of price transparency.