Figure 3.

The ALT activity of one standardized sample (C15) reported by 11 different laboratories is expressed as a multiple of the gender-specific ULN for those laboratories. The disparate ULN values reported by different laboratories causes the results of this one sample to be variably interpreted as 0.66 to 1.75 × ULN if it came from a man and 0.87 to 1.73 × ULN if it came from a woman. If this sample was from a woman, it would be reported as normal by 3 laboratories (E, F, G) and elevated by the other 8 (Figure 3). If it was from a man, it would be reported as normal in 7 laboratories and elevated in 4 (A, B, C, D)