Statistical analysis
SECONDARY
All data were expressed as means ± standard deviations (SDs). A linear mixed model with repeated measures was used to assess the data for the fixed factors of the trial (control group, 40% AOP group, and 80% AOP group) and time (primary and secondary outcomes). The level of significance was set at P < 0.05 for all data. The Bonferroni method was selected as the p-value correction method, and the corrected p-value was directly compared with 0.05. Statistical analyses were performed using SPSS 22.0 (SPSS Inc., Chicago, USA).