Table 1. The frequency distribution of intervention and confounding related variables used in the hierarchical multivariate models, before and after the city-wide sanitation intervention.
| Variables | Categories | Before Intervention (N = 729) | After Intervention (N = 890) | ||||
| n | % | 95% CI * (%) | n | % | 95% CI * (%) | ||
| INTERVENTION | |||||||
| Presence of drainage system of rainwater | 1° tercile (≤0.05) | 276 | 37.9 | 34.3–41.5 | 239 | 26.8 | 23.9–29.8 |
| 2° tercile (>0.05 and ≤0.21) | 211 | 30.3 | 27.0–33.8 | 319 | 35.8 | 32.6–39.0 | |
| 3° tercile (>0.21) | 232 | 31.8 | 28.4–35.3 | 332 | 37.3 | 34.1–40.5 | |
| Absence of open refuse collection points | 1° tercile (≤0.80) | 211 | 28.9 | 25.7–32.4 | 226 | 25.4 | 22.5–28.3 |
| 2° tercile (>0.80 and ≤0.89) | 273 | 37.4 | 33.9–41.0 | 327 | 36.7 | 33.5–40.0 | |
| 3° tercile (>0.89) | 245 | 33.6 | 30.1–37.1 | 337 | 37.8 | 34.7–41.1 | |
| Frequency of households with regular water supply | 1° tercile (≤0.44) | 380 | 52.1 | 48.4–55.8 | 144 | 16.2 | 13.8–18.7 |
| 2° tercile (>0.44 and ≤0.60) | 156 | 21.4 | 18.5–24.5 | 360 | 40.4 | 37.2–43.7 | |
| 3° tercile (>0.60) | 193 | 26.5 | 23.3–29.8 | 386 | 43.5 | 40.1–46.7 | |
| Proportion of households connected to the Bahia Azul sewage system | ≤25% of houses in area | 729 | 100 | — | 100 | 11.2 | 9.2–13.5 |
| >25%, ≤50% of houses | 0 | 0 | — | 160 | 18.0 | 15.5–20.6 | |
| >50%, ≤75% of houses | 0 | 0 | — | 322 | 36.2 | 33.0–39.4 | |
| >75% of houses | 0 | 0 | — | 308 | 34.6 | 31-4–37.8 | |
| CONFOUNDING | |||||||
| Age | 7–10 years | 337 | 46.2 | 42.5–50.0 | 520 | 58.4 | 55.1–61.7 |
| 11–14 years | 392 | 53.7 | 50.1–57.4 | 370 | 41.6 | 38.3–44.9 | |
| Sex | Female | 354 | 48.6 | 44.9–52.2 | 408 | 45.8 | 42.5–49.2 |
| Male | 375 | 51.4 | 47.7–55.1 | 482 | 54.2 | 50.8–57.5 | |
| Mother's education | ≤4 years | 208 | 28.9 | 25.3–32.9 | 202 | 22.7 | 20.0–25.6 |
| >5 and ≤11 years | 361 | 50.1 | 45.8–53.2 | 517 | 58.9 | 54.8–61.3 | |
| >12 years | 151 | 20.9 | 17.8–23.8 | 171 | 19.2 | 16.7–21.9 | |
| Paving of street | Paved | 314 | 43.1 | 39.4–46.7 | 302 | 33.9 | 30.8–37.1 |
| Unpaved | 415 | 56.9 | 53.2–60.5 | 588 | 66.1 | 62.8–69.2 | |
| Number of children <5 years in household | <2 | 342 | 46.9 | 43.2–50.6 | 742 | 83.4 | 80.7–85.7 |
| >2 | 387 | 53.9 | 49.4–57.0 | 148 | 16.6 | 14.2–19.2 | |
| Presence of sewage in 1997 | 1° tercile (≤0.37) | 247 | 33.9 | 30.4–37.4 | 340 | 38.2 | 35.0–41.5 |
| 2° tercile (>0.37 and ≤0.66 | 253 | 34.7 | 31.2–38.3 | 278 | 31.2 | 28.0–34.4 | |
| 3° tercile ( >0.66) | 229 | 31.4 | 28.0–35.0 | 272 | 30.6 | 27.5–33.7 | |
* CI = exact binomial 95%.