Table 2 Criteria for indicators used by the expert panels

Validity:

The extent to which the indicator accurately represents the concept being assessed

Reliability:

The degree of trustworthiness of the data collected by the indicator

Sensitivity to change:

The degree to which the indicator is affected by change in the quality of referral letters

Acceptability:

The degree to which stakeholders find the indicator relevant

Feasibility:

The extent to which it is possible to gather data within defined frames such as economic, legal and time constraints

Simple and communicable:

The degree to which the results are easy to communicate and understood by the intended audience