1. International Comparison of Injury Case-Fatality Rates in the United States and New Zealand Ted Miller, PhD Rebecca Spicer, PhD, MPH Pacific Institute for Research and Evaluation, Calverton, MD, USA John Langley, PhD Shaun Stephenson Injury Prevention Research Unit, University of Otago, Dunedin, New Zealand

2. Objectives To compare injury case-fatality rates between the United States and New Zealand To compare injury case-fatality rates between the United States and New Zealand Use the observed differences to generate new research questions Use the observed differences to generate new research questions

3. Methods Data Data New Zealand E-coded hospital discharge and mortality census data (1992-1996) New Zealand E-coded hospital discharge and mortality census data (1992-1996) United States National Hospital Discharge Survey (1996) United States National Hospital Discharge Survey (1996) 63% of cases E-coded 63% of cases E-coded E-codes for the remainder of cases modeled based on diagnosis and age group. E-codes for the remainder of cases modeled based on diagnosis and age group. United States mortality census data (1996) United States mortality census data (1996) Hospitalized case definition: AIS 3 to 6 only, first admission, not discharged dead Hospitalized case definition: AIS 3 to 6 only, first admission, not discharged dead

4. New Zealand 35,552 Cases United States 744,476 Cases

5. Injury Case-Fatality Rates (CFR)

6. CFR Comparison: by Cause

7. CFR for Cutting/Piercing Injuries: by Intent

8. CFR for Firearm Injuries: by Intent

9. CFR for Poisoning Injuries: by Intent

10. CFR for Motor Vehicle-Related Injuries: by Victim Type

11. Conclusions Case-fatality rates in NZ and the US differ dramatically depending on the cause of the injury. Case-fatality rates in NZ and the US differ dramatically depending on the cause of the injury. Why? Why?

12. Possible reasons for the observed differences Data collection and coding procedures? Data collection and coding procedures? Motor vehicle injuries: Motor vehicle injuries: Road and vehicle standards? Road and vehicle standards? Helicopter transport for the severely injured? Helicopter transport for the severely injured? Firearm injuries: Firearm injuries: Types of firearms? Types of firearms? Greater US experience treating gunshot victims? Greater US experience treating gunshot victims? Poisoning: Poisoning: Poison treatment availability? Poison treatment availability? Types of poisons? Types of poisons? Mechanical injury: occupational differences? Mechanical injury: occupational differences? Burn injury: Risk of house fires in the US? Burn injury: Risk of house fires in the US? Natural/environmental injury: Environment/animal differences Natural/environmental injury: Environment/animal differences

13. Limitations Possible coding differences between countries Possible coding differences between countries Small number of cases, particularly for New Zealand Small number of cases, particularly for New Zealand Misclassification of cause Misclassification of cause