Sample size calculation and statistical analysis
REGRESSION, MAY
The sample size was calculated on the basis of our institutional data. In the review of medical records of patients who underwent nasal surgery from 13 to 2021 to 13 May 2021 at our institution, 55.3% of patients received opioids at the PACU. Assuming that the opioid requirement was reduced by 50% in the educated group, 50 patients in each group were necessary to achieve a power threshold of 80% at the significance level of 5% (two-tailed test). With an expected dropout rate of 10%, 110 patients (55 patients per group) were required.Categorical variables are presented as frequencies and percentages (%), and were analyzed by Chi-square test or Fisher’s exact test as appropriate. Continuous variables were compared by a two-sample t-test or Wilcoxon’s rank-sum test as appropriate, after checking normality with the Shapiro-Wilk test, and are presented as a mean (standard deviation) or median (interquartile ranges). Intention to treat analysis was carried out to compare index opioid (fentanyl) requirements between the groups in the PACU. Risk factors for the opioid requirement at the PACU were analyzed by univariable and multivariable logistic regression with backward stepwise model selection using the Akaike Information Criterion (AIC). The likelihood Ratio test and Hosmer-Lemeshow test were performed for the goodness-to-fit test. The risk was expressed as an adjusted odds ratio (aOR) and 95% confidence interval (95% CI). Statistical significance was assumed when 