Model of Lim et al for Identifying a Patient with Hemochromatosis Who Is Homozygous for C282Y

Patient selection: hemochromatosis, age >= 25 years

Outcome: homozygous for C282Y

Parameters:

(1) serum ferritin concentration in µg/L

(2) transferrin saturation in percent

X =

= (0.09762 * (transferrin saturation)) + (0.0009248 * (ferritin)) - 9.69091

where:

• The original coefficients were rounded. The original values went to 10 decimal points.

• The original paper gave separate equations for men and women but the coefficients were the same.

probability of homozygosity =

= 1 / (1 + EXP((-1) * X))

Performance:

• The area under the ROC curve was 0.89 for women and 0.91 for men.