Study Method

Cost effectiveness analysis (CEA) is a popular methodology for policy makers working within the constraint of limited resources, as it can be applied to a range of interventions to generate a list of interventions that can be ranked from the most to the least cost effective. CEA is concerned with the efficiency with which resources are used to obtain a given health care result. Although not included directly, the effect of patient preferences on cost-effectiveness will be considered through their impact on compliance and treatment seeking behaviour.

The determination of cost depends heavily on the point of view of the analysis.  In the malaria areas of southern Africa, the public sector is the major source of anti-malarial drug treatment, although there is some variation between countries.  This study aims primarily to assess cost effectiveness from the perspective of the public sector provider. Within this context, the direct health care costs (the net costs less any savings) are considered the most important of the costs.  An attempt will, however, also be made to define direct (out of pocket expenses) and indirect (lost income) costs to the patient. 

Cost effectiveness analyses address the value of a therapy in the real world (effectiveness) rather than the results obtained in a clinical trial (efficacy).  Effectiveness will be determined by results obtained in in vivo studies, modified by those of drug utilisation studies (particularly compliance, treatment seeking). Medication may be discontinued once symptomatic relief is attained.  Change from a single stat dose of SP (current treatment in SA) to CAT requiring a 3 day course of artesunate may result in a significant decrease in compliance. Similar concerns are raised even where policy changes from a 3 day chloroquine (current treatment in Swaziland and Mozambique) to CAT therapy due to the rapid clinical effect of artesunate. The effect of CAT on compliance will be evaluated in the Drug Utilisation component of this evaluation, and included in the decision tree analysis of costs per patient treated.

Incremental cost effectiveness is used to measure the additional cost and benefit obtained when comparing one strategy with the next most expensive option, and seeks to answer the question "if option 2 is better than option 1, then at what price?" ¹⁰.  This approach may be considered appropriate in the context of switching from SP (or chloroquine) to CAT.  Both average and incremental cost effectiveness will be evaluated in this study. However results from incremental cost effectiveness may be less easy to generalise since the baseline level of health care varies significantly within South Africa, and more markedly between neighbouring countries.

The cost effectiveness of malaria control measures is frequently measured in Disability Adjusted Life Years (DALYs) averted¹¹.  Using such a generic measure, rather than intermediate measures of benefit such as cases cured, allows for comparison of both preventive and treatment interventions, evaluation of both disability as well as mortality, and allows for comparison with results of other recent cost-effectiveness studies in developing countries.