Fig. 2
From: Clinical measurements obtained from point-of-care ultrasound images to assess acquisition skills
Trainees’ model-derived acquisition-level systematic errors. Shaded areas represent zones of equivalence, which are bounded in each direction by half a standard deviation of mean diameter measurements obtained from the instructor’s ultrasound images (see text for rationale). Color-coded error bars indicate two-sided 90% confidence intervals (CI) that are red if CIs and the point estimates of the mean values are outside equivalence 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 adjusted means of diameters obtained from the instructor’s ultrasound images: IVC maximum 16.2 mm (95% CI 13.3–19.1 mm); IVC minimum 10.3 mm (95% CI 6.7–13.9 mm); RIJ mediolateral 14.4 mm (95% CI 11.7–17.0 mm); and RIJ anteroposterior 11.6 mm (95% CI 9.8–13.5 mm). IVC inferior vena cava, RIJ right internal jugular, max. maximum, min. minimum, ML mediolateral, AP anteroposterior, diam. diameter