['Necessity' determined on the basis of disease severity when prioritising health care interventions].

In the Netherlands, the Priorities in Healthcare [Keuzen in de Zorg] Committee proposed that the prioritisation of healthcare interventions should in part be based on the criterion 'necessity'. However, this criterion has hardly ever been used. It was proposed that 'necessity' should be defined in terms of disease severity. This concept examines the fraction of expected quality-adjusted life years (QALY) that a patient will lose if the condition concerned is not treated. The following two possible applications for healthcare policy were studied. Firstly, relatively necessary care could be fully reimbursed, whereas less necessary care would only be reimbursed in part. Secondly, for relatively necessary interventions a lower cost-effectiveness threshold (relatively high costs per QALY for necessary care) could be accepted. In these cases the concept of disease severity provides a new feasible interpretation of the criterion 'necessity'.