Clinical outcome

An outcome of major clinical importance that is defined on the basis of the disease being studied (e.g. fracture in osteoporosis, relapse rates).

Clinical significance

A conclusion that an intervention has an effect that is of practical meaning to patients and health care providers. Effects identified as statistically significant are not always clinically significant, because the effect is small or the outcome is not important.

Clinical trial

A carefully controlled and monitored research study on human subjects or patients evaluating one or more health interventions.  Each trial is designed to answer specific scientific questions.

Comparative effectiveness

The ability of one treatment, relative to another, to demonstrate clinical effectiveness


the alternative to which the intervention is compared


the value of opportunity forgone as a result of engaging resources in an activity

Cost benefit analysis (CBA)

An economic evaluation comparing alternative interventions in which costs and outcomes are quantified using the same monetary units

Cost consequences analysis

An economic evaluation in which the components of costs and consequences (health outcomes, adverse effects etc.) are measured and presented in their natural units, without any attempt to aggregate the outputs

Cost minimisation analysis (CMA)

An economic evaluation comparing the costs of different interventions that are assumed to produce equivalent benefits

Cost of illness analysis

A determination of the economic impact of a disease or health condition, including treatment costs.

Cost per QALY

A measure used in cost-utility-analysis, expressed as monetary cost per unit of outcome

Cost utility analysis (CUA)

An economic evaluation in which costs are measured in monetary units and outcomes are measured in terms of their utility e.g. using the quality adjusted life year (QALY).


A technology is considered cost effective for a specified indication if the incremental benefits of the technology versus its comparator justify its incremental costs and harms; value for money

Cost-effectiveness analysis (CEA)

An economic evaluation in which costs are measured in monetary units and outcomes are measured in nonmonetary units related to health e.g. as life years gained or clinical events avoided

Cost-effectivenss plane

Graph plotting the difference in effect between the technology of interest and the comparator on the horizontal axis, and difference in costs on the vertical access.

Critical appraisal

The process of assessing and interpreting evidence by systematically considering its validity, results and relevance.