When should an intervention be provided?

The questions of whether, when, and how much to provide of a health care intervention are central to decision making across all levels of health care, from government through to individual clinicians. A recent Editorial in Australian Journal of Physiotherapy declared that the benefit-harm trade-off method (Barrett et al 2005) was a 'clearly superior' approach to determine whether effects of an intervention were clinically important (Ferreira and Herbert 2008). This is a contentious position deserving further exploration. The benefit-harm trade-off method involves presenting patients with a series of hypothetical scenarios where the benefits of an intervention are varied while costs, harms, and inconveniences of the intervention are held constant. From the perspective of a health economist, the point at which a clinical effect is sufficient to warrant implementation could be argued as being the point at which the benefits obtained from its provision outweigh the costs. The cost-benefit analysis approach directly addresses this question by (to simplify) placing a monetary value on the costs incurred consequent to provision of the intervention, and weighing this against a monetary valuation of the health benefits gained (Drummond et al 1993). To this point, the underlying concept of cost-benefit analysis is consistent with that of the benefit-harm trade-off method. However, cost-benefit analysis is typically undertaken from a 'societal' perspective in line with welfare economic theory rather than from the 'patient' perspective, meaning that a broader set of costs and benefits are considered. Patients are rarely the sole stakeholders and decision makers in decisions about health care provision and utilisation. The decision to make available particular health care services is commonly made by health care administrators and professionals rather than by individual patients. The expectations of individual patients also cannot be expected to represent the views of the other stakeholder groups that fund healthcare programs such as governments, insurance companies, and the tax-paying public. The benefit-harm trade-off method requires patients to understand fully the costs and consequences of the scenarios put before them to be able to make an informed decision. There is a balance between depth of explanation and potential for participants to remember and integrate all of this information into their decision-making process. Hence this approach is likely to have limitations when applied to patient populations with limited cognitive processing capacity, or for evaluation of complex health care interventions, or interventions with a range of potential side effects or benefits. So, what value …