Table 3.
Differences in differences between study groups calculated as pupae per person index (PPI)a, Breteau index (BI) and container index (CI) from baseline to 9 weeks and to 29 weeks follow-upsb
| Mean change in intervention clusters | Mean change in control clusters | Dif of dif (95% CI)c | Wilcoxon p-value | t student p-value | ||
|---|---|---|---|---|---|---|
| PPI | After first intervention (baseline to 1st follow-up) | 0.129 (from 0.75 to 0.88) |
−0.096 (from 0.4 to 0.31) |
0.225 (−0.125 to 0.49) |
NS | 0 |
| After second intervention (baseline to 2nd follow-up) | −0.501 (from 0.72 to 0.22) |
−0.055 (from 0.36 to 0.3) |
−0.446 (−0.49 to −0.40) |
0.01 | 0 | |
| 1st vs 2nd follow-up | −0.936 (from 1.15 to 0.22) |
0.011 from 0.29 to 0.3) |
−0.947 (−0.99 to −0.89) |
0.01 | 0 | |
| BI | After first intervention (baseline to 1st follow-up) | −0.079 (from 0.14 to 0.06) |
−0.031 (from 0.08 to 0.05) |
−0.049 (−0.051 to −0.046) |
0 | 0 |
| After second intervention (baseline to 2nd follow-up) | −0.078 (from 0.12 to 0.06) |
−0.05 (from 0.08 to 0.03) |
−0.029 (−0.084 to 0.02) |
NS | 0 | |
| 1st vs 2nd follow-up | −0.038 (from 0.08 to 0.05) |
−0.013 (from 0.05 to 0.03) |
−0.025 (−0.029 to −0.02) |
NS | 0 | |
| CI | After first intervention (baseline to 1st follow-up) | −0.024 (from 0.042 to 0.018) |
−0.016 (from 0.034 to 0.018) |
−0.008 (−0.009 to −0.006) |
NS | 0 |
| After second intervention (baseline to 2nd follow-up) | −0.028 (from 0.047 to 0.02) |
−0.02 (from 0.035 to 0.015) |
−0.01 (−0.01 to −0.005) |
NS | 0 | |
| 1st vs 2nd follow-up | −0.005 (from 0.024 to 0.019) |
−0.004 (from 0.019 to 0.015) |
−0.001 (−0.002 to 0.001) |
NS | NS |
NS: not significant.
a PPI median values: baseline with 20 clusters: intervention clusters: 0.7, control clusters: 0.33; diff 0.38; p value: 0.04 (Wilcoxon test); first follow-up with 20 clusters: intervention clusters: 0.72, control clusters: 0.18, diff 0.54, p value 0.01 (Wilcoxon test); second follow-up with 8 clusters: intervention clusters: 0.24, control clusters: 0.09, diff 0.15, p value NS (Wilcoxon test); baseline with 8 clusters: intervention clusters: 0.72, control clusters: 0.22; first follow up with 8 clusters: intervention clusters: 1.15, control clusters: 0.29.
b Mixed model analysis showed no significant variation of PPI at the cluster level.
c 95% CIs.