# Presentation: 318928

## 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

**Notes:**
I am running out of time, but before I finish, I thought I would give you a taster of the proposed set of criteria for judging the soundness of indicators. This is based on a couple of papers that  I wrote with Steve Jarvis and others, as well as one that John Langley and I wrote - but they have been supplemented following email exchanges between some of the group members over the last few months.

They are...(see what is written in the report).

## 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 now?

## 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