2.4 Statistical Analysis
Accurate power analysis cannot be done since studies of this kind have
not been performed before; however, sample size was inferred based on an
estimated difference in the mean SNOT-22 scores of 8.9 (clinically
significant). Calculations were based on an effect size of 0.45 and a
power of 0.8. Stratified groups and postoperative changes within groups
were compared using the Wilcoxon two-sample test. P-values were
considered significant if less than or equal to 0.05. Analysis was done
on selected questions within the SNOT-22 and ETDQ-7 questionnaires that
related to ear pain or ETD. All three instruments were analyzed for
correlation of change between the preoperative and 6-week postoperative
visit. Pearson correlation coefficients were calculated for SNOT-22,
NOSE, and ETDQ-7 instruments for all groups.
Results