Statistics
Differences in the atrial septum and pulmonary artery band parameters
were assessed using the paired student t-test and differences between
the two groups (AS and HLHS) was assessed using the independent student
t-test. Inter- and intra-user variability was assessed using the
intraclass correlation coefficient. Statistical analysis was performed
using Stata version 14.1 (StatCorp, Texas). Change in variables over
time was modelled using multilevel mixed effects linear regression, with
time modelled as a categorical variable. All models included patient age
as a covariate. Change over time was expressed using 3 P values: time,
group (left versus right) and group-time interaction (see table 3 legend
for further explanation).