GSTM1 and anemia (phenotype): While mortality was significantly higher in children with a Hb <5g/dl (pooled RR=1.92 vs >5g/dl, 95% CI 1.7–2.2), evidence for an increased risk with less severe anaemia was not conclusive: although the risk of death was increased for a Hb <8g/dl, the confidence intervals were wide11.