Similarly, each 0.1 mg/kg increase in primaquine dose was associated with an increased risk of moderate/severe anaemia (Hb < 10 g/dL; AOR 1.60, 95% CI 1.28–1.99) or severe anaemia (Hb < 7 g/dL; AOR 1.89, 95% 1.49–2.40) (Table 3). Here, GSTM1 is linked to anemia (phenotype).