Tuberculous pleural effusion (n=20) Malignant pleural effusion (n=20) Transudative pleural effusion (n=18) χ2 P value
Fructose 11.65 17.95 16.90 4.175 0.124
L-Serine 13.80 18.60 14.10 1.866 0.393
Tyrosine 15.10 16.90 14.50 0.403 0.818
L-Threonine 20.90‡ 14.90 10.70 6.782 0.034*
Creatinine 18.20 10.00 18.30 5.855 0.054
Choline 20.80 11.40 14.30 5.979 0.050
Methionine 17.00 8.80‡ 20.70 9.572 0.008**
Acetic acid 13.60 18.20† 14.70 7.760 0.021*
L-Valine 20.10 13.00 13.40 4.106 0.128
Glutamic acid 16.00 13.50 17.00 0.839 0.657
4-Aminobutyrate 20.80 11.40 14.30 2.147 0.342
L-glutamic acid 19.30 11.30 15.90 4.160 0.125
Ornthine 15.80 12.10 17.30 2.240 0.326
*P < 0.05 ** P < 0.01. Data are presented as mean rank
†p < 0.05 compared with each of the other two groups
‡ p < 0.05 compared with transudative pleural effusion
Table 5: Statistical results of Kruskal-Wallis (K-W) test.