Measure for measure: The quest for valid indicators of non-fatal injury incidence

In this edition of Public Health, McClure and colleagues report on research that considered the criterion validity of indicators based on serious long bone fracture and length of stay in hospital. They found that neither were sensitive or specific indicators for serious injury as defined by an Injury Severity Score (ISS) of 16 or more. They contend that their study findings ‘… strongly support a return to a measure similar in intent to that encapsulated in the original UK Green Paper…’. We contend that their analysis does not provide any empirical evidence to support their view that there should be a return to the Green Paper: Our Healthier Nation indicator. Furthermore, we consider the analyses that they carry out to validate both the Saving Lives: Our Healthier Nation and the serious long bone fracture indicators are flawed. We agree that national (or state) indicators are very influential. They encourage preventive action and resource use aimed at producing favourable changes to these indicators. However, each of the four non-fatal indicators considered in their analysis have problems. Formal validation of existing indicators is necessary and the following aspects of validity should be addressed: face; criterion; consistency; and completeness and accuracy of the source date. Taking into account the current national data systems in England, possible options for one or more national non-fatal unintentional injury indicators have been proposed in our paper. Furthermore, the International Collaborative Effort on Injury Statistics (ICE) Injury Indicators Group is about to embark on the development of a strategic framework for the development of valid indicators of non-fatal injury occurrence.