Table 1.
Differences in Estimates of Prevalence of Hookworm Infection (Any Intensity) Based On Single (1×1) or Duplicate Slide (1×2) Examination of a Single Stool Samplea
| Dataset | Expected Results for 1×1 Scheme | Expected Difference in Prevalence Between 1×2 and 1×1 Schemes | ||
|---|---|---|---|---|
| Prevalence of Infection (95% CI) | Mean Egg per Gram (95% CI) | Absolute (95% CI) | Relative (95% CI) | |
| Mulanda, Tororo, Uganda | 23.4 (21.3–25.4) | 258 (181–350) | 4.5 (3.3–5.5) | 1.19 (1.15–1.24) |
| Kwale, Kenya (TUMIKIA) | 16.7 (16.1–17.2) | 168 (149–191) | 2.4 (2.2–2.6) | 1.14 (1.13–1.16) |
| Prevalence ≤5% | 2.4 (1.8–2.9) | 11 (5–17) | 0.6 (0.3–0.9) | 1.25 (1.13–1.40) |
| Prevalence 5%–15% | 8.8 (8.1–9.5) | 81 (62–105) | 1.5 (1.2–1.8) | 1.17 (1.14–1.21) |
| Prevalence 15%–25% | 17.2 (16.1–18.3) | 167 (135–200) | 2.6 (2.1–3.1) | 1.15 (1.12–1.18) |
| Prevalence 25%–35% | 26.1 (24.6–27.7) | 299 (220–417) | 3.9 (3.2–4.7) | 1.15 (1.12–1.18) |
| Prevalence 35%–45% | 35.5 (33.1–37.8) | 381 (295–480) | 4.4 (3.3–5.5) | 1.12 (1.09–1.16) |
| Prevalence >45% | 48.1 (45.2–51.2) | 465 (381–556) | 5.0 (3.6–6.4) | 1.10 (1.07–1.14) |
Abbreviations: CI, confidence interval.
aEstimates are based on 10 000 bootstraps of the entire datasets. For the Kenyan data, data were also stratified based on overall prevalence at the cluster level (N = 120). Results for the Starworms data are not shown because differences between the 2 sampling schemes were nonsignificant for all of the worm species in all of the countries. Absolute differences are expressed as percentage points; relative differences are expressed as ratios of 1×2 over 1×1. The 95% CI is based on the 2.5th and 97.5th percentiles of bootstrap results.