Frequency distribution of selected variables between the clear cell renal cell carcinoma cases and control subjects.

aStudent's t-test for age and BMI distributions between cases and controls; two-sided χ2-test for others selected variables between cases and controls.
Frequency distribution of selected variables between the clear cell renal cell carcinoma cases and control subjects.

针对病例组与对照组的年龄及身体质量指数（BMI）分布，采用学生t检验（Student's t-test）进行组间比较；针对其余选定变量，则采用双侧卡方检验（two-sided χ²-test）进行组间比较。透明细胞肾细胞癌（clear cell renal cell carcinoma）病例组与对照受试者间选定变量的频数分布情况。