This study has potential limitations.We were not able to control for maturation
(post to 1-year FU) because children who were assigned to the waiting list at the
start of the study were randomized to ICBT or GCBT at the completion of the waiting
period. This methodological limitation (because of ethical considerations) is inherent
in long-term follow-ups. Another limitation involves sample size—it may be
the case that true differences exist in the efficacy of these two treatment conditions,
but the differences were not large enough to be detected within the present sample.
Thus, conclusions regarding the apparent equivalency of the ICBT and GCBT
must be qualified. However, given the effect sizes for CBT treatments for anxious
children (see Flannery-Schroeder & Kendall, 2000; Kendall et al., 1997), one can
conclude that GCBT and ICBT are more efficacious than waitlist.