Statistical analysis
REGRESSION
In describing summary statistics, categorical variables are reported as numbers and percentages, while continuous variables are reported as means and standard deviations (or medians and interquartile ranges, based on the normality of the data). The proportion of cases with a positive S-test result was compared among the three dose groups using the chi-square test for rater 1 (0.1 mL/kg versus 0.3 mL/kg, 0.1 mL/kg versus 0.5 mL/kg, 0.3 mL/kg versus 0.5 mL/kg). These comparisons were only made for the results of rater 1 (YO) and not rater 2 (MT), in order to minimize the risk of Type I error inflation. For the S-test, the interrater agreement for each dose was evaluated using Cohen’s kappa statistic. The proportions of cases with positive V-test results in the three different dose groups were compared using the chi-square test. The proportions of positive test results for the S- and V-tests in each dose group were compared using McNemar’s chi-square test. For the V-test, the paired t-test was used to compare the blood flow velocity between the baseline and post-injection phase for each of the three dose groups (0.1 mg/kg, 0.3 mg/kg, and 0.5 mg/kg). Logistic regression was used to calculate the crude odds ratios (ORs) of positive S- and V-test results in the different dose groups (i.e., 0.1 mg/kg and 0.3 mg/kg using 0.5 mg/kg as the reference). Cases with missing data were excluded from the analysis. Data were analyzed using Stata 17.1 (StataCorp, College Station, TX, USA), with a two-sided 