Choose Your Own Data-Analytic Adventure

bob.8
So what should I write in the IRB proposal'

First, since you randomized the intervention and control groups, they are equal (in expectation). Therefore, if you observe a statistically significant difference in anxiety, you can reasonably infer that the difference was caused by your child life intervention.

If you are going to dichotomize MYPAS scores (into "anxious" and "not anxious"), then you need a reasonable cut score, preferably specified now.

In the literature, a score of 30 or above has been considered "clinically anxious."

Great. Use the cut-off score of 30 to define clinically anxious pediatric patients.
Conduct a 2x2 contingency table analysis to explore the relationship between the intervention and clinical anxiety.
Using the '2 statistic, test the null hypothesis that there is no relationship in the population between the intervention and clinical anxiety. If you reject the null, conclude that there is a relationship in the population, that intervention patients are less likely to be clinically anxious, and that the child life intervention caused this effect.
Use differences in percentages (from your sample) to convey the effect size.

What should I do about the section for statistical power and sample size'


You reply:
"That's beyond me. Good luck. Let me know how it goes."
or
"Statistical power' Sample size' We can give it a shot."
or
"Let's reconsider how you will characterize the outcome."