Inter-rater and intra-rater reliability of quantitative ultrasound in preterm infants: an observational cohort study.

= 81). The MiniOmni was the QUS device, and the smallest probe, CS probe (length 24 mm, range 2200-4700 m/s, and max depth 4.5 mm), was used for all subjects. Measurements were taken at the mid-tibia location. Inter-rater reliability was calculated using 2-way random-effects intraclass correlation coefficients (ICC); intra-rater reliability was calculated using 2-way mixed-effects ICC. 95% CI were calculated for each. Value of ICC estimates less than 0.5, between 0.5 and 0.75, between 0.75 and 0.9, and greater than 0.90 are indicative of poor, moderate, good, and excellent reliability, respectively. Intra-rater reliability at 1 mo post-birth and 36 wk PMA was excellent across all operators. Inter-rater reliability was more variable with good reliability at 1-mo measurements (0.84, 0.78-0.90, 95% CI) and excellent reliability at 36 wk PMA (0.94, 0.90-0.96, 95% CI). Our study demonstrated that QUS is a reliable diagnostic tool and a feasible potential alternative to current diagnostic methodologies for MBPD in extremely preterm infants.