A population dynamic approach to evaluating the impact of school attendance on the unit cost and effectiveness of school-based schistosomiasis chemotherapy programmes

H. CARABIN a1c1, M.-S. CHAN a1 and H. L. GUYATT a1
a1 The Wellcome Trust Centre for the Epidemiology of Infectious Disease, University of Oxford, South Parks Road, Oxford OX1 3FY, UK


This paper presents a first attempt at modelling the possible cost and effectiveness of reaching non-enrolled children through school-based programmes using empirical data from Egypt. A sex/school-attendance/age-structured population dynamic model was used to predict trends in infection and early disease. Four treatment delivery strategies were compared: school-based (coverage of 85%) and school-aged targeted (coverage of 25, 50 and 85%). The school-aged targeted strategies also included the school-based programme. For each alternative strategy, the maximum unit cost was calculated to obtain a cost-effectiveness ratio equal or smaller to the one obtained with the school-based programme (unit cost of US$ 0·60). The analysis showed that, for S. mansoni in Lower Egypt, a programme where only 85% of children attending school were treated would still prevent 77% of the early disease cases prevented with a programme where 85% of all school-age children were treated. However, using the school-aged targeted strategy, from US$ 0·06 to US$ 1·03 extra unit costs could be spent to reach non-enrolled children and still be more cost-effective. Treating non-enrolled children is an important consideration in maximizing the effectiveness of treatment programmes while maintaining a cost-effectiveness comparable to school-based delivery.

(Received December 11 1999)
(Revised February 4 2000)
(Accepted February 4 2000)

Key Words: schistosomiasis; population dynamic model; school attendance; school-aged children; chemotherapy; cost-effectiveness analysis.

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