2.7 Statistical analysis
Data was processed using Statistical Package for Social Science (SPSS)
19.0. Continuous variables were expressed as mean ± standard deviation
(SD) or median (interquartile range, IQR). Categorical variables were
presented as count (percentage). The differences between groups were
assessed using Student’s t-test for normally distributed continuous
variables, and Mann-Whitney U tests for non-normally distributed
continuous variables, as appropriate. Predefined outcomes stratified by
average TAC C0, IPV or CYP3A5 genotype were
analyzed by Kaplan-Meier analysis and compared using
the Log-rank test. Time from
transplant to DSA, CLAD or death was modeled using Cox proportional
hazards regression. Potential risk factors included age at transplant,
sex, body mass index (BMI), comorbidities (hypertension, hyperlipidemia
and diabetes), transplant-related data and TAC exposure. The variables
with a P value < 0.2 in the univariate analysis were
included in the multivariate analysis, which employed a forward
likelihood ratio-test approach for constructing final Cox survival
models. P < 0.05 was considered of statistical
significance.