Figure 2. Flow chart of inclusion and exclusion of courses in analysis.

*Protocol changeover dates given in Table 2 were strictly applied in reviewing the data, even though implementation in the seven village clinics probably did not occur instantly. Accordingly, some data exclusions were for courses commenced within a few days of a protocol changeover. 92% of exclusions for this reason would have been excluded because of one or more of the other exclusion criteria, which were applied in sequence. EDTA, CaNa₂EDTA.