Abstract: 

Generic service and policy interventions impact on organisations at some distance from the patient.  They rely for their effect on changing intermediate variables (such as knowledge and culture) or prompting more tangible service change closer to the patient. Their effects on an organisation are therefore diffuse and difficult to measure at the patient level. Generic service interventions are also developed and refined in use. The implications of these factors for the measurement of effectiveness have been discussed previously by the authors and others.  In this talk I will discuss the further implications of these issues for health economic assessments. I suggest a series of steps that can be used in a flexible manner in a health economic analysis of these ‘difficult to evaluate’ interventions.  One of these steps involves calculation of the option value.