In a multivariable analysis using the combined data set from the MICE procedure, which included all patients in the model after the imputation of a second Hb within six months for those patients without, we found that AZT was still not predictive of early severe anaemia; OR 1.43 (95% CI 0.92 - 2.21). This evidence concerns the gene GSTM1 and anemia (phenotype).