Economic evaluation of parasitic diseases: A critique of the internal and external validity of published studies

It was estimated that in 1990, major parasitic diseases accounted for 11.7% of the disease burden from communicable disease. As advances in the preven tion, diagnosis and treatment of parasitic diseases are made and implemente d, there is a growing economic literature to help decision-makers choose th e most efficient control method. The aim of this paper is to identify, desc ribe and analyse the available published data on the efficiency of control strategies against parasitic diseases. Internal validity is assessed throug h the quality of economic evaluations over time using a series of standard questions, and external validity is assessed in terms of the potential to e xtrapolate results to other settings. This leads to a discussion of the leg itimacy and feasibility of pooling data or results from studies for priorit y setting in the health sector, resulting in three recommendations: to incr ease the coverage of economic evaluations for parasitic diseases and types of interventions; to improve the internal validity of studies through guide lines and review procedures; and to explore the external validity of resear ch results by examining their predictive validity across settings.