Sample size and power: The hypothesis that TMAO is significantly elevated in subjects with T2D with versus without incident MACE was based on at least a 30% difference.15 17 22 (link) Using these values, the minimum required sample size is 216 (108 per group) with a type I error rate of 0.05% and 80% power.
Data are presented as mean±SD or as median and IQR for continuous variables and as proportions for categorical variables. Paired t-tests were used to compare the matched cases and controls for continuous variables if the normality assumption was not violated. Otherwise, non-parametric Wilcoxon signed rank tests were conducted. Comparison between matched cases and controls for categorical variables was performed using McNemar’s tests or marginal homogeneity tests. A linear mixed effects regression model was used to test the effect of MACE on plasma levels of TMAO after adjusting for within-pair correlations and multiple covariates. Conditional logistic regression analysis was used to test the predictive power of TMAO on MACE. Statistical significance was set at two-tailed p<0.05. IBM SPSS Statistic 21.0 (Chicago, Illinois, USA) was used for all statistical analyses.
Data are presented as mean±SD or as median and IQR for continuous variables and as proportions for categorical variables. Paired t-tests were used to compare the matched cases and controls for continuous variables if the normality assumption was not violated. Otherwise, non-parametric Wilcoxon signed rank tests were conducted. Comparison between matched cases and controls for categorical variables was performed using McNemar’s tests or marginal homogeneity tests. A linear mixed effects regression model was used to test the effect of MACE on plasma levels of TMAO after adjusting for within-pair correlations and multiple covariates. Conditional logistic regression analysis was used to test the predictive power of TMAO on MACE. Statistical significance was set at two-tailed p<0.05. IBM SPSS Statistic 21.0 (Chicago, Illinois, USA) was used for all statistical analyses.
