Malaria_Taiwan 1991 TWN.
| Methods | Dates of study: 1955 Location of study: Taiwan Malaria endemicity (prevalence): 4.12% in all ages (May 1955 survey); 2.93% in all ages (November 1955) [Low] Transmission season: Not described Malaria species: P. falciparum, P. malariae, P. vivax Vector species: A. maculatus, A. minimus, A. sinensis Study design: Uncontrolled before‐and‐after study Evaluation design: Cross‐sectional surveys and passive surveillance |
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| Participants | Age groups included: All ages, except infants Sample size Intervention group 1 mean (range): 1520 (1502‐1537) |
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| Interventions | Intervention group 1: MDA administered to all persons, except infants, in Lanyu with a single dose of chloroquine (12 mg/kg) in November 1955. Coverage not specified. Co‐intervention with IRS using DDT. | |
| Outcomes | Parasitaemia prevalence No adverse event surveillance conducted No adverse events reported |
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| Notes | Post‐MDA (> 12 months) estimated using survey data from April‐May 1957 and April 1960 | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | No comparison group |
| Allocation concealment (selection bias) | High risk | No comparison group |
| Baseline imbalance (selection bias) | High risk | No comparison group |
| Contamination protection | High risk | No comparison group |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | No comparison group |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | No comparison group |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Insufficient reporting of attrition/exclusions to permit judgement |
| Selective reporting (reporting bias) | Low risk | The first three malariometric baseline surveys reported consisted of only a portion of the entire population on the island. Subsequent surveys examined all inhabitants. While these disproportionate samples could result in a certain bias when compared to the remaining surveys that comprised the entire population, the investigators weighted the first three surveys according to the natural distribution of the population. |
| Other bias | Low risk | No other bias detected |