Injury Indicators Colin Cryer CHSS, University of Kent, England on behalf of the ICEII Group
Aim • To identify robust measures (indicators) of injury occurrence (fatal and non-fatal) that can be compared by person, place (including internationally) and time.
Example 1 • Target: • to reduce serious unintentional injury (sufficient to require a hospital stay of 4 or more days) by at least a tenth. • Concern: • injury indicator is not stable over time (or across geographic area)
Example 2 • Target: • To reduce the rate of accidents - here being defined as those which involve a hospital visit or consultation with a family doctor - by at least a fifth. • Concerns • will focus attention on minor injury • ascertainment influenced by extraneous factors.
Example 2 (contd.) • Evidence to support those concerns: • Cryer PC, et al. Why the Government was right to change the ‘Our Healthier Nation’ accidental injury target. Public Health 2000; 114: 232-7
From Aim to Objectives Example 1 Example 2 Need for robust case definition for indicators Need for criteria for an ideal indicator
Objectives • Identify the characteristics of an ideal indicator. • Agree robust definitions of a case that will be the basis of each indicator. • Identify problems that may compromise the validity of each proposed indicator and how they may be addressed. • Analysis of indicators in current use, and propose a robust set of indicators.
Scope • Proposal: • To focus on occurrence of injury (initially) • Subsequently, focus on: • burden of injury • exposure to hazards • attributes relating to prevention
Criteria for a sound indicator • Case definition: anatomical or physiological damage. • The injury cases ascertained should be important (eg. in terms of disablement and / or threat-to-life). • Cases should be ascertained from routinely or easily collected data. • The probability of a case being ascertained should be independent of extraneous factors. • The indicator should capture all the events in universe that the indicator aims to reflect.
Discussion: • Criteria for a sound indicator • Case definition • Assess existing indicators • Identify problems • (Propose reliable indicators)