Evaluation of Benefit-Risk
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CURRENT OPINION
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Evaluation of Benefit-Risk Silvio Garattini Mario Negri Institute for Pharmacological Research, Milan, Italy
Abstract
Drug authorization, prescription and utilization are all based on benefitrisk assessment. This is made difficult by the apparent lack of objective means to measure the balance and by limitations regarding each of the two items. Benefit is sometimes measured by surrogate indicators of a real clinical advantage. It is assumed to be applicable to individuals even though it is measured in populations, and is represented in different ways that may convey different messages to physicians and patients. Risks are also hard to predict on an individual level. They may also be overlooked or revealed later than benefit, thus biasing the balance for a long time. Their causal relationship with the treatment is often not fully established. The benefit-risk balance itself has no generally recognized measure. This is why benefits and risks are hard to compare; either one or both may occur in single patients, and a risk-benefit profile that is acceptable in severe diseases may not be acceptable in diseases with a favourable prognosis. Pharmacoeconomics offers promising methods of health outcomes modelling using QALYs that take into consideration quality of life as well as survival. Primarily conceived as a guide for establishing the value of a treatment, they may prove useful as a means of trading efficacy and safety. However, quality of life is not always – or adequately – assessed in clinical studies. It is also not clear which is the most appropriate model to calculate QALYs for clinical purposes and how it can be used as a predictive tool at the individual level.
The benefit-risk balance is theoretically the basis of every medical prescription. The balance is assessed from the results of randomized controlled trials, which are usually powered to establish benefits, though not to detect all the risks. Regulatory authorities employ the benefit-risk relationship to grant marketing authorizations even when the information is not complete. National health systems base decisions on reimbursement of new drugs on cost effectiveness that also reflects benefit-risk balance. However, since there is still no precise quantitative definition of this balance, using it is often
only a subjective decision. The concepts of benefit and risk are clear and measurable but what is missing is the link between the two. 1. Benefit Any advantage to patients’ health can be considered a benefit; however, the advantage can be established for a group of patients or a population but seldom predicted for single patients. Advantage means essentially a slowing of the progression of the disease or of disturbing or invalidating clinical symptoms, or increased survival
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demonstrated by the stringent methods of clinical trials. Comparative data are needed when there is at least one standard treatment.[1] The concept of benefit has gradually been extended to ‘s
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