International Comparison of Injury Case-Fatality Rates in the

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

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

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

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

Injury Case-Fatality Rates (CFR)

CFR Comparison: by Cause

CFR for Cutting/Piercing Injuries: by Intent

CFR for Firearm Injuries: by Intent

CFR for Poisoning Injuries: by Intent

CFR for Motor Vehicle-Related Injuries: by Victim Type

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

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

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