Chapter 5 Health technology assessment
Health technology assessments bridge the gap between licensing and everyday clinical practice.
The critical steps involve:
• A systematic review of the evidence.
• Estimating cost-effectiveness.
• Drawing appropriate conclusions on which decision-makers can act.
A cost–effectiveness analysis attempts to provide a rational basis for decision-making in the face of resource constraints.
There are three stages in the health technology assessment of a product:
The scope
1. Obviously the product, or group of products, under investigation needs to be characterised.
2. The nature of the comparator health technology (or technologies) also requires definition. Depending on the circumstances, the comparator might be another pharmaceutical product indicated for the same condition; it might be a device or procedure used for the same or similar purposes; or it might be ‘best supportive care’. In any event, the comparator should reflect current clinical practice.
3. At the start of any health technology assessment, the clinical outcome(s) of interest should be decided. The most desirable, of course, is the ‘ultimate outcome’, such as dead versus alive or recovered versus not recovered. There are circumstances, however, when an assessment is focused on an ‘intermediate’ (or surrogate) outcome where there is confidence that this reflects the ultimate outcome. For example, in the assessment of statins for the treatment of hypercholesterolaemia, a decision would need to be taken as to whether the long-term ‘ultimate’ outcome (i.e. reduction in coronary artery disease) should be used; or whether the assessment should be concerned with an ‘intermediate’ outcome (i.e. a reduction in LDL cholesterol).
4. The type of evidence required to demonstrate the effectiveness of a product must also be determined. In many instances this may be restricted to the results of randomised controlled trials. There may be circumstances where other study designs are more appropriate. In the assessment of a vaccine, for example, evidence from randomised controlled trials may usefully be supplemented by the results of observational studies that have examined its efficacy under circumstances that more closely reflect its performance in the ‘real world’.
5. Decisions must also be made about the form any economic evaluation should take. These include the economic perspective and the type of analysis that is most appropriate. These issues are discussed later.
Clinical effectiveness
3 Analysing the data
• The study’s bibliographic reference.
• The type of study (e.g. randomised controlled trial, case–control study).
• Number of patients in each arm.
• Patient characteristics (e.g. age, gender).
• Study setting (e.g. hospital inpatients, GPs’ surgeries).
• Intervention(s) including dose(s) and route(s) of administration.
• Comparator interventions (e.g. placebo, active comparator).
