Table 5.
Multivariable analysis of factors associated with the school-level S. mansoni PRR among 199 schools surveyed during year 5 survey in Kenya
| Covariate | S. mansoni (Coefficient (95% CI), P-value)* | |
|---|---|---|
| Prevalence | PRR | |
| Baseline prevalence, % | ||
| < 1 | −48.95 (−54.79;−43.12), P < 0.001 | |
| 1–10 | −43.58 (−49.94;−37.23), P < 0.001 | |
| 10–50 | −37.14 (−43.03;31.24), P < 0.001 | |
| > 50 | Reference | |
| Treatment covariates | ||
| Treatment rounds with PZQ | ||
| 0 | Reference | |
| One | 2.49 (−4.77;9.77), P = 0.500 | −380.59 (−610.36;−150.81), P = 0.001 |
| Two | −6.73 (−12.39;−1.06), P = 0.020 | −143.78 (−387.49;99.93), P = 0.248 |
| Three | −5.91 (−9.78;−2.04), P = 0.003 | −165.68 (−301.08;−30.29), P = 0.016 |
| ≥ Four | Insufficient obs | −298.19 (−446.50;−149.87), P < 0.001 |
| Household WASH covariates | ||
| Proportion of children reporting an improved household water source at home, % | ||
| < 25 | Reference | |
| 25–50 | 1.47 (−0.33;3.28), P = 0.110 | |
| 50–75 | −0.82 (−2.82;1.18), P = 0.424 | |
| > 75 | −1.70 (−3.40;0.01), P = 0.015 | |
| School WASH covariates | ||
| Overall pupil per latrine ratio | ||
| < 30 | 104.78 (−22.23;231.79), P = 0.106 | |
| 30–60 | −128.74 (−277.05;19.58), P = 0.089 | |
| 60–90 | 65.99 (−138.45;270.44), P = 0.527 | |
| > 90 | Reference | |
S. mansoni = Schistosoma mansoni; PRR = prevalence relative reduction; WASH = water, sanitation, and hygiene.
Regression coefficients of association together with their 95% CIs were determined using multivariable mixed-effects linear regression models with a random intercept at county and subcounty levels. Statistical significance of the coefficients was determined by the absence of zero overlapping in the 95% CIs (values in bold). In all the models, negative values of the coefficients indicated a decrease in the rate of school-level infection or low values of PRR, whereas positive values of the coefficients indicated an increase in the rate of school-level infection or high values of PRR.