Findings from yesterday’s discussion • Definition of an indicator needed • the injury indicator signals the occurrence of a phenomenon • Precise definition of an injury needs to be included (the blue book?) • Something about standardisation / comparability / harmonisation. • Criteria should be split into >1 dimension • quality • usefulness • practicality of measurement • Hierarchy of criteria needed • how much fuzziness can we tolerate
Criteria for a sound indicator - No Replace by…. Criteria for identifying an optimal indicator
Criteria • Case definition: anatomical or physiological damage - ? • The injury cases ascertained should be important (eg. in terms of disablement and / or threat-to-life).- Replace • Cases should be ascertained from routinely or easily collected data.- Reword • The probability of a case being ascertained should be independent of extraneous factors.- Yes • The indicator should capture all the events in universe that the indicator aims to reflect.-Reword
Criteria - 1 • (A) The indicator should reflect the occurrence of injury satisfying some case definition of anatomical or physiological damage. • (B) The indicator should reflect a well defined information objective. • (C) It should be possible to use existing data systems, or it should be practical to develop a new systems, to provide data for computing the indicator.
Criteria - 2 • (D) The probability of a case being ascertained should be independent of social, economic, and demographic factors, as well as health service supply and access factors. • (E) The indicator should be derived from data that are inclusive or representative of the target population that the indicator aims to reflect. • [Note: the intention is that (E) also implies not going beyond the bounds of the target population]
What about one more? • (F) The indicator should be based on events that are associated with significantly increased risk of impairment, functional limitation, disability, or death, decreased quality of life, or increased cost.
One (of many) possible case definition: • Any case that dies or an injury case (classified by ICD) that has a probability of death above a predefined level, eg. based on ICISS
Any case that dies or an injury case (classified by ICD) that has a probability of death above a predefined level, eg. based on ICISS • (A) Anatomical / physiological damage - Yes • (B) Reflect information objective - N/a • (C) Existing or practical new systems - Yes • (D) Unbiased - Yes (if severity threshold high enough) • (E) Representative of the target population - Could be • (F) Burden - Yes
What we need to resolve • Who are the injury indicator group? • Let me know if you want to continue your involvement • Where can we get to before Montreal? • criteria + discussion • examples of case definitions • critique of a few key indicators • more?? • Work to: • identify other possible case definitions • examine some current indicators of common interest