No impact of the malaria IST intervention was observed for prevalence of anaemia at either 12 or 24 months ( adjusted risk ratio [ Adj.RR ] : 1.03 , 95 % CI 0.93-1 .13 , p = 0.621 and Adj.RR : 1.00 , 95 % CI 0.90-1 .11 , p = 0.953 ) respectively , or on prevalence of P. falciparum infection or scores of classroom attention .