Table 2 Distribution characteristics of raw and numerically transformed salivary alpha-amylase values

(U/mL)

Square root

(sqrt [U/mL])

Natural log

(ln[U/mL])

n

430

430

430

Mean

17.48

3.96

2.65

Median

13.00

3.60

2.55

Standard deviation

11.70

1.21

0.57

Coefficient of variation (%)

66.94

30.56

21.51

Skewness

1.79

1.11

0.31

Kurtosis

3.27

1.01

0.16

Fifth percentile

6.50

2.48

1.79

95^th percentile

43.75

6.06

3.71