부산대학교 도서관

Background: Published databases of normal pediatric echo measurements are limited by insufficient sample sizes to assess the effects of age, sex, and race. Variable indexing methods have resulted in a wide range of Z-scores for a single measurement. Interobserver variability has been reported as 5% difference or more. This multicenter study sought to determine Z-scores for common echo measurements adjusted for body surface area (BSA) and stratified by age, sex, and race.Methods: Healthy non-obese children ≤18 yrs old with a normal echo were enrolled at 19 centers into 36 groups based on 6 age categories, sex, and race (White, African American, Other). Data (age, sex, race, height, weight) and echo images were collected, and the Core Lab derived protocol measurements from each echo. Z-score models involved choosing indexed values (measurement divided by BSA raised to the power a) that were normally distributed without residual dependence on BSA. The models were tested for the effects of age, sex, and race. Raw measurements from models with and without these effects were compared, and <5% difference (interobserver variability threshold) was considered a clinically insignificant effect.Results: Of the 3566 subjects, 90% had measurable images. BSA transformations (BSA) that met protocol criteria were used for each measurement. Multivariable regression revealed statistically significant effects by age, sex, and race for all outcomes, but they were deemed clinically insignificant during comparison of models with and without these effects, thereby allowing for a single set of Z-scores independent of age, sex, and race. The derived Z-score models (a, mean indexed values, and standard deviations) for each outcome are in Table 1.Conclusion: This is the largest normative database of echo measurements from a healthy population of racially diverse children across the full range of ages and body sizes. Our derived Z-scores are based on BSA and are not affected by age, sex, or race.