Discrepancy Rates and Clinical Impact of Imaging Secondary Interpretations: A Systematic Review and Meta-Analysis

To conduct a meta-analysis of studies investigating discrepancy rates and clinical impact of imaging secondary interpretations and to identify factors influencing these rates.

EMBASE and PubMed databases were searched for original research investigations reporting discrepancy rates for secondary interpretations performed by radiologists for imaging examinations initially interpreted at other institutions. Two reviewers extracted study information and assessed study quality. Meta-analysis was performed.

Twenty-nine studies representing a total of 12,676 imaging secondary interpretations met inclusion criteria; 19 of these studies provided data specifically for oncologic imaging examinations. Primary risks of bias included availability of initial interpretations, other clinical information, and reference standard before the secondary interpretation. The overall discrepancy rate of secondary interpretations compared with primary interpretations was 32.2%, including a 20.4% discrepancy rate for major findings. Secondary interpretations were management changing in 18.6% of cases. Among discrepant interpretations with an available reference standard, the secondary interpretation accuracy rate was 90.5%. The overall discrepancy rates by examination types were 28.3% for CT, 31.2% for MRI, 32.7% for oncologic imaging, 43.8% for body imaging, 39.9% for breast imaging, 34.0% for musculoskeletal imaging, 23.8% for neuroradiologic imaging, 35.5% for pediatric imaging, and 19.7% for trauma imaging.

Most widely studied in the context of oncology, imaging secondary interpretations commonly result in discrepant interpretations that are management changing and more accurate than initial interpretations. Policymakers should consider these findings as they consider the value of, and payment for, secondary imaging interpretations.