GSTM1 and anemia (phenotype): Table 3 presents the hierarchical logistic regression model of anaemia risk and shows that only children with heavy S. mansoni intensities were more likely to be anaemic, defined as Hb < 11.0 g/dL, compared with uninfected children (Odds ratio: OR = 2.3, 95% credible interval: 1.1–4.3; Table 3).