Clearing asymptomatic parasitaemia increases the specificity of the definition of mild febrile malaria.
In clinical trials, the specificity of the disease endpoint is critical to an accurate estimate of vaccine efficacy. We used a logistic regression model to analyse parasite densities among children before and after treatment with antimalarials, in order to estimate the impact that clearing asymptomatic parasitaemia had on the specificity of the endpoint of febrile malaria. The malaria attributable fever fraction was higher after antimalarial treatment (i.e. fever and parasitaemia were more likely to be causally related), implying that drug treatment prior to monitoring decreased the misclassification of febrile malaria. In intervention studies with febrile malaria as an endpoint, clearing asymptomatic parasitaemia increases the study's power more effectively than raising the threshold parasitaemia.
Bejon
Philip
P
Kenya Medical Research Institute, Centre for Geographical Medicine Research (Coast), Kenya. pbejon@kilifi.kemri-wellcome.org
Mwangi
Tabitha
T
Lowe
Brett
B
Peshu
Norbert
N
Hill
Adrian V S
AV
Marsh
Kevin
K
D000962:Antimalarials / Q000627:therapeutic use*; D001831:Body Temperature; D002648:Child; D002986:Clinical Trials as Topic; D005334:Fever / Q000453:epidemiology / Q000209:etiology* / Q000469:parasitology; D006801:Humans; D016015:Logistic Models; D008288:Malaria / Q000150:complications* / Q000453:epidemiology / Q000469:parasitology; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology*; D018512:Parasitemia / Q000209:etiology* / Q000473:pathology; D012044:Regression Analysis
D000962:Antimalarials