From: The concentration of three anti-seizure medications in hair: the effects of hair color, controlling for dose and age
Hair Color
Number of
Mean PHT
Standard
Subjects
Concentration
Deviation
Black
24
16.35
5.79
Brown
18
16.76
7.68
Blond
8
7.92
2.92
Gray
10
6.55
4.82
Overall Mean
60
13.71
7.32