Table 3.
Malaria case incidence in children (aged 6 months to 10 years)
| Number of clinical episodes | Follow-up time, child-years | Incidence per child per year | Adjusted incidence rate ratio (95% CI)* | p value† | |
|---|---|---|---|---|---|
| Pyrethroid-only group | |||||
| Year 1 | 194 | 605·1 | 0·32 | 1 (ref) | .. |
| Year 2 | 449 | 793·4 | 0·57 | 1 (ref) | .. |
| Overall | 643 | 1398·5 | 0·46 | 1 (ref) | .. |
| Pyriproxyfen group | |||||
| Year 1 | 161 | 604·5 | 0·27 | 0·94 (0·60–1·48) | 0·8029 |
| Year 2 | 418 | 787·4 | 0·53 | 1·02 (0·67–1·55) | 0·9235 |
| Overall | 579 | 1391·9 | 0·42 | 0·99 (0·66–1·50) | 0·9801 |
| Chlorfenapyr group | |||||
| Year 1 | 79 | 603·8 | 0·13 | 0·46 (0·28–0·74) | 0·0016 |
| Year 2 | 248 | 790·6 | 0·31 | 0·61 (0·40–0·94) | 0·0250 |
| Overall | 327 | 1394·4 | 0·23 | 0·56 (0·37–0·86) | 0·0072 |
| Piperonyl butoxide group | |||||
| Year 1 | 79 | 591·8 | 0·13 | 0·53 (0·33–0·85) | 0·0090 |
| Year 2 | 381 | 788·9 | 0·48 | 1·11 (0·73–1·67) | 0·6306 |
| Overall | 460 | 1380·7 | 0·33 | 0·92 (0·61–1·38) | 0·6809 |
For time-by-study group interaction, pinteraction=0·0001. Each intervention group is compared to the pyrethroid group for the same timepoint.
*
Adjusted for baseline cluster-level variables used in restricted randomisation.
†
p<0·017 was considered statistically significant after Bonferroni correction.