Table 3. Effect of area of residence and age on the protective efficacy of IPTc against clinical episodes of malaria.
| Outcomes According to Area of Residence and Age Category | IPTc | Placebo | Unadjusted RR (95% CI) | p-Value | Adjusted RR (95% CI) | PE (95% CI) | p-Value | ||
| Episodes (Years at Risk) | Incidence Ratea | Episodes (Years at Risk) | Incidence Ratea | ||||||
| Clinical malaria defined as fever or history of fever in the last 24 h and asexual parasitaemia ≥5,000/µl | |||||||||
| Locality | |||||||||
| Djoliba | 11 (73.77) | 0.15 (0.08–0.27) | 74 (73.49) | 1.00 (0.80–1.26) | 0.13 (0.10–0.18) | <0.001 | 0.15 (0.08–0.28) | 85 (72–92) | <0.001 |
| Siby | 70 (93.32) | 0.75 (0.59–0.94) | 308 (90.57) | 3.40 (3.04–3.80) | 0.13 (0.07–0.24) | <0.001 | 0.22 (0.17–0.29) | 78 (71–83) | <0.001 |
| Ouelessebougou | 45 (202.55) | 0.22 (0.17–0.30) | 292 (190.20) | 1.53 (1.37–1.72) | 0.21 (0.16–0.26) | <0.001 | 0.14 (0.10–0.20) | 86 (80–90) | <0.001 |
| Age (mo) | |||||||||
| 3–11 | 6 (68.64) | 0.09 (0.04–0.19) | 52 (66.60) | 0.78 (0.59–1.02) | 0.11 (0.05–0.26) | <0.001 | 0.13 (0.05–0.29) | 87 (71–95) | <0.001 |
| 12–23 | 12 (83.00) | 0.14 (0.08–0.25) | 134 (72.40) | 1.85 (1.56–2.19) | 0.08 (0.04–0.14) | <0.001 | 0.07 (0.04–0.13) | 93 (87–96) | <0.001 |
| 24–35 | 38 (76.63) | 0.50 (0.36–0.68) | 173 (77.96) | 2.22 (1.91–2.58) | 0.22 (0.15–0.33) | <0.001 | 0.23 (0.15–0.34) | 77 (66–85) | <0.001 |
| 36–47 | 36 (72.51) | 0.50 (0.36–0.69) | 153 (67.84) | 2.26 (1.92–2.64) | 0.22 (0.15–0.31) | <0.001 | 0.21 (0.15–0.31) | 79 (69–85) | <0.001 |
| 48–59 | 34 (66.91) | 0.51 (0.36–0.71) | 156 (66.43) | 2.34 (2.00–2.74) | 0.21 (0.14–0.32) | <0.001 | 0.22 (0.15–0.32) | 78 (68–85) | <0.001 |
| Clinical malaria defined fever or history of fever in the last 24 h and asexual parasitaemia regardless of the density | |||||||||
| Locality | |||||||||
| Djoliba | 12 (72.05) | 0.17 (0.09–0.29) | 90 (73.40) | 1.22 (1.0–1.50) | 0.13 (0.10–0.18) | <0.001 | 0.14 (0.10–0.18) | 86 (82 –90) | <0.001 |
| Siby | 83 (90.86) | 0.91 (0.74–1.13) | 372 (86.41) | 4.30 (3.88–4.76) | 0.13 (0.07–0.24) | <0.001 | 0.14 (0.07–0.26) | 86 (74 –93) | <0.001 |
| Ouelessebougou | 54 (199.25) | 0.27 (0.21–0.35) | 370 (185.82) | 1.99 (1.80–2.20) | 0.21 (0.16–0.26) | <0.001 | 0.21 (0.16–0.26) | 79 (74–84) | <0.001 |
| Age (mo) | |||||||||
| 3–11 | 10 (68.15) | 0.15 (0.08–0.27) | 72 (65.96) | 1.09 (0.86–1.38) | 0.13 (0.07–0.26) | <0.001 | 0.14 (0.07–0.27) | 86 (73–93) | <0.001 |
| 12–23 | 15 (81.60) | 0.18 (0.11–0.30) | 153 (71.07) | 2.15 (1.83–2.52) | 0.08 (0.05–0.14) | <0.001 | 0.08 (0.05–0.14) | 92 (86–95) | <0.001 |
| 24–35 | 47 (75.18) | 0.62 (0.47–0.83) | 206 (76.20) | 2.70 (2.36–3.10) | 0.23 (0.17–0.31) | <0.001 | 0.23 (0.16–0.33) | 77 (67–84) | <0.001 |
| 36–47 | 39 (70.23) | 0.55 (0.40–0.76) | 200 (65.44) | 3.06 (2.66–3.51) | 0.18 (0.13–0.25) | <0.001 | 0.18 (0.13–0.25) | 82 (75–87) | <0.001 |
| 48–59 | 38 (65.04) | 0.58 (0.42–0.80) | 194 (63.98) | 3.03 (2.63–3.49) | 0.19 (0.13–0.27) | <0.001 | 0.19 (0.13–0.28) | 81 (72–87) | <0.001 |
a
Incidence rate expressed as number of episodes/child/year. Note that this is based on the 3-mo surveillance period and does not correspond to an annual rate.