There was no effect modification by frequency of contact (weekly compared with monthly), but we did observe a greater effect of SQ-LNSs on Hb concentrations and the prevalence of anemia among studies that reported high compliance than among those reporting lower compliance (MD: 4.78 g/L compared with 2.59 g/L; Figure 4A, Supplemental Figure 6A10; and PR: 0.68 compared with 0.84; Figure 4B, Supplemental Figure 6B10, respectively). This evidence concerns the gene GSTM1 and anemia.