Interrater reliability of emergency medicine residents in measurement of optic nerve sheath diameter with computed tomography.

ABSTRACT

OBJECTIVES: Many studies have recently been conducted on measuring optic nerve sheath diameter (ONSD) with computed tomography (CT). However, no studies focused on the interrater reliability in ONSD measurements with CT yet. Our first aim was to investigate the interrater reliability of the emergency medicine residents in the measurement of the ONSD with CT. Our secondary aim was to evaluate the interrater reliability and agreement of the emergency medicine residents and neuroradiologist measurements, which is the gold standard. METHODS: Twelve residents (six seniors and six juniors) and a neuroradiologist measured ONSD in twenty different CTs in axial and sagittal planes. The interrater reliability was calculated by the intraclass correlation coefficient (ICC), and the level of agreement in categorical variables was calculated by kappa (ĸ) analysis. RESULTS: We found that the interrater reliability level of all residents was "good" (ICC 0.824), for seniors was "good" (ICC 0.824), and for juniors was "moderate" (ICC 0.748) in the measurement of ONSD. ICC was 0.812 for axial, and 0.783 for sagittal plane measurements. The interrater reliability between residents and the neuroradiologist measurements was "good" (ICC 0.891), and the agreement was found to be "good" (ĸ 0.688; P < 0.001). The sensitivity of residents in detecting increased ONSD was 78%, and specificity was 90.8%. CONCLUSION: The ONSD measurements with CT performed by the residents are reliable in themselves, and they are compatible with the gold standard measurements.