Sample size calculation and statistical analyses
The sample size calculation was informed by Meija et al. [The statistical analyses were performed using PASW Statistics for Windows, version 18.0 (SPSS Inc, Chicago, IL, USA). The study conducted an intention-to-treat analysis involving all randomized participants and a per-protocol analysis restricted to those who followed the designated treatment. Descriptive statistics were used to describe patient and cycle characteristics. Continuous data were presented as the means ± standard deviations or medians (ranges) for normally distributed and nonnormally distributed data, respectively, whereas categorical data were expressed as numbers and percentages. For categorical data, Pearson chi-squared, Yates’ continuity correction, or Fisher’s exact test were performed to compare the proportions between two groups. The independent Student’s t-test was used for normally distributed continuous data, while the Mann-Whitney U-test was used for nonnormally distributed continuous data for comparing the mean or median, respectively, between two groups. Absolute differences were computed by substracting percentages of the combination group’s outcomes from percentages of the CC-alone group’s outcomes, while the rate ratio was computed by percentages of the combination group’s outcomes divided by percentages of the CC-alone group’s outcomes. The level of statistical significance was set at 