6.9. Impact assessment

As RDTs are introduced and used, it will be important to measure their impact on the diagnosis and treatment of malaria in the public and private sectors, and on the disease itself. Such assessments aim to identify parameters whose modification will maximize the benefits of RDTs, and will also provide information needed for a cost-effectiveness analysis of RDTs. Parameters to be assessed include: drug usage; treatment-seeking behaviour; access to RDTs; the time between diagnosis and treatment; management of patients; incidence of severe disease, morbidity and mortality; treatment failure; and drug resistance.

One parameter of interest is the utilization of diagnostic results. Experience indicates that some health care providers treating a patient with suspected malaria will ignore negative RDT results and give antimalarial drugs regardless. Similar observations have been made in the case of microscopic diagnosis (53). Such patterns of disease management negate the benefit offered by confirmatory diagnostic tests and strategies to understand and correct this behaviour should be investigated.

Delaying the emergence of drug resistance by reducing the number of unnecessary treatments has been postulated as one of the potential benefits of RDTs. Another strategy that aims to delay drug resistance is malaria combination therapy (e.g. mefloquine plus artemisinin derivatives in areas of multidrug resistance) (54). While studies on the potential impact of RDTs and combination therapy on the development of drug resistance might provide useful information for malaria control policies, it must be acknowledged that in practice such studies are complex.