Abstract

Objectives

South Korea has expanded insurance reimbursement for brain magnetic resonance imaging (MRI) under its single-payer national health insurance system. This study assessed the nationwide impact of this policy change on the diagnostic and management-related utility of brain MRI and overall diagnostic efficiency.

Methods

Nationwide claims data for brain MRI scans performed for headaches or dizziness between 2015 and 2022 were analyzed. Patients with clinically significant imaging findings (PCSIFs) were defined as those receiving follow-up observation or treatment after a new diagnosis. Low-value imaging cases, including those were later subject to selective reimbursement, were also identified. Efficiency was calculated as the number of MRI scans required to obtain one additional PCSIF across the prepolicy, expansion, and adjustment periods.

Results

The annual MRI volume increased from a mean of 93 694 before implementation to 716 085 during expansion, and then declined to 630 705 during the adjustment period. The use of MRI for headaches or dizziness increased by 1402%. PCSIFs exceeded the expected trends by 12 423 cases (26.6%) during expansion and 7808 cases (13.1%) during adjustment. Low-value imaging cases accounted for 45.4% of MRI scans during expansion. An average of 22 to 23 low-value MRI examinations were performed for each additional patient with diagnostically or clinically actionable findings. Overall, the policy markedly increased MRI use, while nearly half of additional scans were low value.

Conclusions

Expanded reimbursement without strict clinical criteria increased MRI use but reduced diagnostic efficiency. Policies should be guided by evidence-based indications to ensure efficient resource utilization and achieve clinically meaningful outcomes.