Fig. 3
From: Clinical measurements obtained from point-of-care ultrasound images to assess acquisition skills
Trainees’ model-derived acquisition-level sporadic errors. Shaded areas represent noninferiority zones, which are bounded only in the direction of larger trainee variance by a quarter of the variance of diameter measurements obtained from the instructor’s ultrasound images (see text for rationale). Color-coded error bars indicate one-sided 90% confidence intervals (CIs) that are red if CIs and the point estimates of variance values are outside noninferiority zones; yellow if CIs are outside but point estimates are within the zones; and green if CIs are entirely within the zones. The vertical dashed line represents the variance in diameter means obtained from instructor-acquired ultrasound images. With the instructor obtaining ultrasound images, intraclass correlation coefficients (the fractions of total variance attributable to patients) for IVC and RIJ veins were 0.88 (95% CI 0.65–0.95) and 0.69 (0.35–0.93) for max. and min. diameters; and 0.83 (0.59–0.99) and 0.63 (0.38–0.83) for ML and AP diameters, respectively. IVC inferior vena cava, RIJ right internal jugular, max. maximum, min. minimum, ML mediolateral, AP anteroposterior, diam. diameter