1. Simon W. Rabkin et al. JACEP 2017;3:756-766
For Men the QT Interval Corrected for Heart Rate for Different QTc Formulae Boxplots of the QTc for each formula are plotted, grouped by heart rate in intervals of 5 beats/min. Both the spline QTc and the spline QTc from cross-validation (labeled Spline QTc-CV) are included. The solid line is the fitted regression line from the regression of a linear, quadratic, and cubic trend on QTc for each QTc formulae. The dashed line shows the fitted regression line on the subset of data with heart rates between 40 and 120 beats/min. Plots are annotated with the permutation p value, which compares the F statistic for linear, quadratic, and cubic trends in each comparator formula with the F statistics for the cross-validated spline. The permutation p value from the trimmed analysis, where only data from ECGs with recorded heart rates between 40 and 120 beats/min were used, are also included. ECG = electrocardiography.
Simon W. Rabkin et al. JACEP 2017;3:
2017 American College of Cardiology Foundation