Multivariate correlation between PSI and Ce, Cp Multivariate correlation X Y Group I Group II X1=Cp X2=Ce (mcg / ml) PSI R=0, 280 R2=0, 079 PSI=1, 284Cp - 5, 051Ce+79, 059 (p<0, 01) R=0, 355 R2=0, 126 PSI=0, 938Cp - 3, 995Ce+79, 699 (p<0, 01) 14 3.3.6.4.