Table 3.
Adjusted Prevalence and Mean of Infection Outcomes at Baseline and 6 Weeks After the Interventiona
| Outcome | Baseline (95% CI) |
6 Wk (95% CI) |
Adjusted Relative Difference, %b | P Value Comparing 6 Wk to Baseline |
|---|---|---|---|---|
| Prevalence | ||||
| Microscopy positive, n (%) | 135 (19.2) | 59 (8.6) | <.0001 | |
| Adjusted prevalence, all schools | 19.5 (12.1–29.9) | 10.0 (7.6–13.0) | −48.8 | <.0001 |
| High transmissionc | 27.8 (17.5–41.2) | 16.1 (12.3–20.9) | −41.9 | <.0001 |
| Lower, seasonal transmissiond | 11.3 (2.8–36.5) | 3.8 (1.9–7.5) | −66.5 | .008 |
| PCR positive, n (%) | 257 (36.5) | 184 (26.9) | <.0001 | |
| Adjusted prevalence, all schools | 33.9 (30.4–37.7) | 25.6 (22.5–29.0) | −24.5 | <.0001 |
| High transmission | 55.7 (50.4–61.7) | 36.1 (31.3–41.7) | −35.2 | <.001 |
| Lower, seasonal transmission | 14.0 (10.9–18) | 15.7 (12.4–19.9) | +12.2 | .40 |
| Anemic, n (%)e | 106 (15.1) | 72 (10.5) | .01 | |
| Adjusted prevalence, all schools | 12.5 (10–15.7) | 8.7 (6.6–11.4) | −30.8 | .003 |
| High transmission | 16.1 (11.4–22.8) | 12.1 (9–16.3) | −36.6 | .007 |
| Lower, seasonal transmission | 10.3 (7.6–13.9) | 8.0 (5.5–11.5) | −22.4 | .15 |
| Mean | ||||
| Hemoglobin, g/dL, mean (SD) | 12.28 (1.46) | 12.56 (1.36) | .0002 | |
| Adjusted mean,f all schools | 12.35 (12.2–12.5) | 12.64 (12.5–12.8) | 2.4 | <.0001 |
| High transmission | 11.9 (11.9–12.1) | 12.2 (12.2–12.4) | 3.1 | <.0001 |
| Lower, seasonal transmission | 12.6 (12.6–12.7) | 12.8 (12.8–12.9) | 1.8 | .003 |
Abbreviations: CI, confidence interval; GEE, generalized estimating equation; PCR, polymerase chain reaction.
Log binomial GEE models for adjusted prevalence adjusted a priori for sex, age, season, and visit, including nested clustering by individual and school.
Relative difference in prevalence is the difference between prevalence at baseline and after 6 weeks divided by baseline prevalence.
High transmission schools were in Maseya and Makhuwira.
Lower, seasonal transmission schools were in Bvumbwe and Ngowe.
Defined as hemoglobin less than 11.0 g/dL. Anemia models adjusted for PCR results for Plasmodium falciparum at baseline.
Adjusted mean hemoglobin and 95% CIs estimated using linear GEE models.