2. Comparing relevant alternatives

Below, different types of costs are described that should be considered when conducting an economic analysis in HTA. Cost item classification may vary in many ways, such as the costs of health-care technologies that are covered by the health-care sector, other sectors or patients and families. Time, productivity or wider-economic costs can also be classified separately. The inclusion or exclusion of cost items may depend upon chosen perspective or analytical approach.

Costs are a product of resources, such as:

-       Units of medicines or devices.

-       Services, staff hours, etc.

-       Facility time.

The unit cost is the cost incurred in order to produce, store, and sell one unit of a particular product; the unit cost includes all fixed costs and all variable costs involved. Ideally, unit costs are a standard measure of the real value of a product, but in practice these are often estimated through interviews or accounting data.

When costing a resource, care must be taken that this is carried out in a clear and transparent manner using appropriate costing methods. For example, when costing practitioner services, care must be taken to distinguish between 'charges' (the amount billed by the practitioner) and 'costs' (the amount billed for services used – e.g blood test, x-ray imaging), particularly where doctors are able to charge different fees to different patient groups or insurance providers.

Economists must also decide which costs to include in the assessment. Temporary absence from work due to illness (either of a patient or of a carer), reduced working capacity due to illness and disability or lost productivity due to early death all have an economic impact. For example, people who are unable to work are unable to earn an income and contribute to the economy (e.g. as taxpayers). If the analysis is conducted from the perspective of a health facility such as a hospital, these costs may not be included.

Even among evaluations claiming to be based on a particular situation, costs and outcomes may vary widely or be incorrectly applied. However, it is generally agreed that all costs related to the disease or technology in question should be included in the analysis.