Statistical analysis
SD
The continuous and categorical data were reported as mean ± SD and frequency and relative frequency. The normality of the continuous data was evaluated using the Kolmogorov-Smirnov test and Q-Q plots. The non-normal positively-skewed data underwent a logarithmic transform. Continuous, categorical, demographic and clinical characteristics of the study participants were compared between the two groups using the independent t-test and Chi-squared test. Within-group and between-group comparisons were performed in terms of the main outcomes using a linear mixed-effects model. The effects of confounding factors were controlled by adjusting for the baseline outcomes in cases of significant practical or statistical differences. An analyzer blinded to the grouping analyzed the data in SPSS Statistics for Windows, version 16.0 (SPSS Inc., Chicago, Ill., USA).