Clinical Trials

❘❙❚■ Chapter 4 | Endpointsand technology, which are done to compare the quality of life of patients indifferent treatment groups or the costs of care of new treatments (which areusually more expensive than standard treatments), have become increasinglyrelevant in the approval and reimbursement of new therapies.There are two main measures of health economics: quality-adjusted life-years(QALYs) gained – a measurement of the duration of an individual’s life, takinginto account the well-being that they experience during that time [11] – and cost.These measures can also be combined to give a cost-effectiveness ratio, which isthe cost of gaining an extra year of life or a benefit in the quality of life for thepatient. The most robust cost-effectiveness studies are conducted alongside clinicaltrials, and these collect resource-use costs for all subjects from each center.Advantages of health-economic endpointsWhile other treatment-specific endpoints such as sight-years gained, symptomfreetime, and cases of disease prevented can also be used [12], they cannoteasily be compared directly. Since the primary economic question is how to get themost benefit from health expenditure, a US panel on cost-effectiveness hasrecommended using a QALY analysis where possible in order to be able to makecomparisons across diseases [13,14]. By calculating the cost per QALY gained fordifferent treatments, healthcare providers can compare where best to invest theirlimited resources.One of the interesting differences between clinical trial reports and cost analysesis that, often, trial reports focus only on the worst or first event that a patientexperiences, while cost analyses aim to calculate the cost of all events experiencedby each patient.Limitations of health-economic endpointsEstimating health-economic endpoints alongside clinical trials is a relativelyrecent concept and, therefore, is only as good as the experience of the economicinvestigators. The data captured for an economic analysis might not even be usedif the treatment is both more expensive and less effective than standard care.Many assumptions often need to be made in an economic analysis, making thedata less robust. Economic analyses might not be easily transferable acrosscountries since the cost of care can be very different internationally, and clinicalresults are dependent on local practice patterns and the availability of facilities.Certain disease states affect the patient only briefly and might not have a longtermimpact if they are not fatal. For example, a collapsed lung might not killa patient, so the negative impact on the patient’s quality of life is only brief andtherefore the cost-effectiveness of treating the condition would be unfavorable.44