Sample group

Number

Correlation coefficient (R)

Fitting equation

All samples

4920

0.965

y = 2.6065x + 11.04

Non-thalassemia

4463

0.880

y = 2.325x + 19.482

Thalassemia

457

0.968

y = 2.8098x + 5.8982

α-thalassemia

311

0.966

y = 0.3496x – 1.8008

β-thalassemia

133

0.962

y = 0.3279x – 0.0392

α & β-thalassemia

13

0.980

y = 0.3316x – 0.3217