The exponential formula and Fridericia's formula were equally useful for screening for QT prolongation in children, yielding the lowest MSR and AIC values among 11 evaluated formulas.
Observational (n=23,861)
Which formula is most useful for correcting the QT interval to screen for QT prolongation in children?
The exponential formula and Fridericia's formula are equally useful and superior to other formulas for correcting the QT interval to screen for QT prolongation in children.
We evaluated the usefulness of 11 formulas for correcting the QT interval in children, including the square root, cubic root, logarithmic, linear, exponential, and inverse formulas using the Mean-squared residual (MSR) values and Akaike Information Criterion (AIC) in 8,086 first-graders, 9,989 seventh-graders, and 5,786 tenth-graders. The subjects were divided into six groups according to age and sex. MSR and AIC values were lowest in all of the groups for the exponential formula (eQTc) and Fridericia's formula (fQTc). We then evaluated the relative usefulness of these two formulas by determining the optimal value for parameter k using the following exponential model: eQTc = (QT interval)/(RR interval)k. The best-fit value for k was different for each group. However, the tentative abnormal eQTc and fQTc values, determined by statistical analysis, were equivalent in all groups when 0.31 was used as the exponential parameter k. These results suggest that the exponential formula and Fridericia's formula are equally useful for screening for QT prolongation.
Aihoshi et al. (Sun,) conducted a observational in QT prolongation screening (n=23,861). Exponential and Fridericia's formulas vs. Other QT correction formulas was evaluated on Mean-squared residual (MSR) values and Akaike Information Criterion (AIC). The exponential formula and Fridericia's formula were equally useful for screening for QT prolongation in children, yielding the lowest MSR and AIC values among 11 evaluated formulas.