Sample characteristics by baseline level of physical function (WOMAC Function Subscale Quartiles).

CVD = Cardiovascular disease.*P-values test the hypothesis that of no differences among the four WOMAC function quartiles and were obtained using ANOVA (continuous, normally distributed covariates), Wilcoxon rank sum tests (ordinal covariates), and chi-square tests (categorical covariates).

CVD即心血管疾病（Cardiovascular disease）。P值用于检验四个WOMAC功能四分位数分组间无差异的假设，其计算分别针对连续、正态分布协变量采用方差分析（ANOVA）、针对有序协变量采用Wilcoxon秩和检验、针对分类协变量采用卡方检验。