Hospital Separations Identification of records for use in tabulating of national injury data Susan G. Mackenzie Presented at the ICE meeting in Washington, September 2006

Questions What approaches to identifying injury hospital separation records for national tabulation are used in different countries? What are the results of the different approaches? Should ICE recommend an approach?

Methods – Survey of approaches to record selection Survey of ICE members Survey of ICE members Which version of ICD is used for hospital Which version of ICD is used for hospital separation data? separation data? Record identification Record identification By Diagnosis or External cause code? or both? By Diagnosis or External cause code? or both? All or selected? All or selected? Tabulation by External cause? Tabulation by External cause? If yes, all or selected? If yes, all or selected? 15 responses received 15 responses received

Methods – Analysis overview Identify the different approaches used to select hospital separation records for tabulation Identify the different approaches used to select hospital separation records for tabulation Apply each of the approaches to the same set of hospital separation data Apply each of the approaches to the same set of hospital separation data Compare the groups of records retrieved using the different approaches Compare the groups of records retrieved using the different approaches Total numbers of records Total numbers of records Numbers of particular types of injuries, classified by external cause Numbers of particular types of injuries, classified by external cause

Thanks for the information Australia James Harrison Australia James Harrison Canada Susan Mackenzie Canada Susan Mackenzie Colombia Andrés Fandiño-Losado Colombia Andrés Fandiño-Losado Victor Hugo Álvarez Castaño Victor Hugo Álvarez Castaño Denmark Birthe Frimodt-Moller, Denmark Birthe Frimodt-Moller, Jens Lauritsen Jens Lauritsen El Salvador Oscar Salinas, Gerardo De Cosio El Salvador Oscar Salinas, Gerardo De Cosio Israel Limor Aharonson-Daniel Israel Limor Aharonson-Daniel Jamaica Yvette Holder Jamaica Yvette Holder The Netherlands Saakje Mulder The Netherlands Saakje Mulder New Zealand Colin Cryer, John Langley New Zealand Colin Cryer, John Langley Trinidad and Tobago Roanna Morton-Williams Bynoe Trinidad and Tobago Roanna Morton-Williams Bynoe United States Lois Fingerhut United States Lois Fingerhut

More thanks AfricaOlive Kobusingye AfricaOlive Kobusingye South AfricaRichard Matzopoulos South AfricaRichard Matzopoulos JapanTatsuhiro Yamanaka JapanTatsuhiro Yamanaka European Union Maria Segui-Gomez European Union Maria Segui-Gomez Information from 11 countries and the EU study available for analysis

ICD version used to classify hospital separations ICD-10 ICD-9 ICD-9-CM ICD-10 modification Netherlands Israel Colombia Australia 1 other EU United States Denmark Canada 5 EU El Salvador New Zealand Jamaica Trinidad and Tobago 16 other EU

Approaches used to identify injury records – Diagnosis Based on the principal, primary, or first- listed, diagnosis code on the record Based on the principal, primary, or first- listed, diagnosis code on the record Use records with any diagnosis in the Injury and Poisoning chapter Use All records with any diagnosis in the Injury and Poisoning chapter Use selected records with a diagnosis in the Injury and Poisoning chapter Use selected records with a diagnosis in the Injury and Poisoning chapter injuries Community injuries Trauma

Approaches used to identify injury records –External cause Based on the first-listed External cause on the record Based on the first-listed External cause on the record Use records with an External cause Use All records with an External cause Use selected records with an External cause Use selected records with an External cause Exclude adverse effects (AE) Trauma

ICD codes used to identify records for injury hospitalization tabulation Diagnosis codes External cause codes All Selected All Selected DNK AUS – community NLD CAN – trauma COL ISR – trauma NZL CAN – Exclude AE SLV USA – community JAM EU study

Methods – Dataset Used Hospital Morbidity Database from the Canadian Institute for Health Information Used Hospital Morbidity Database from the Canadian Institute for Health Information Initial selection: Initial selection: All acute care separations from one Canadian province for fiscal year All acute care separations from one Canadian province for fiscal year N=126,217. N=126,217.

Methods – Record selection From the 126,217 acute care records From the 126,217 acute care records Considered the primary diagnosis and the first listed external cause and selected records where: Considered the primary diagnosis and the first listed external cause and selected records where: The or poisoning (in chapter XVII of ICD-9) The primary diagnosis was an injury or poisoning (in chapter XVII of ICD-9) or or There was an. There was an external cause on the record. 14,772 possible injury records were retrieved 14,772 possible injury records were retrieved

External cause on record PresentNot present ICD-9 Diagnosis chapter XVII - Injury & poisoning Other 14,772 04,499 (30%) 8,254 (56%) 2,019 (14%) 12,7532,019 10,273 4,499 14,772 AB CDC

Total records retained, by approach

Percentage of records retained where diagnosis is not from the injury chapter 000

Distribution of non-injury diagnoses when identification is based on external cause, by approach Percentage of non-injury diagnoses ICD- 9 chapter

Numbers of all records and all records with external causes, by approach

Selected unintentional external causes: Adverse effects 00

Selected external causes: All records, Unintentional injuries, falls

Selected unintentional external causes: Motor vehicle traffic crashes, Other transport, Fire/flames

Selected unintentional external causes: Poisoning, Natural & environmental, (near) Drowning 0

Selected unintentional external causes: Suffocation, Other foreign bodies 00

Selected external causes: Other intents

Conclusions There is variation between and within countries in capacity to classify injury diagnoses and external causes for hospital separation records There is variation between and within countries in capacity to classify injury diagnoses and external causes for hospital separation records Where the information is available, the selection approach used can make an important difference in the number and nature of injury records retrieved Where the information is available, the selection approach used can make an important difference in the number and nature of injury records retrieved External cause approaches generally yield more records than the injury diagnosis approaches External cause approaches generally yield more records than the injury diagnosis approaches

Questions Is there a preferred selection approach? Is there a preferred selection approach? Is there value in using different selection approaches for different purposes Is there value in using different selection approaches for different purposes Acute injury occurrence Acute injury occurrence Total burden of injury Total burden of injury Issues Issues Diagnosis vs. external cause as primary selection? Diagnosis vs. external cause as primary selection? or possibly a combination of diagnosis and external cause? If diagnosis: All, Community, Trauma, (Other)? If diagnosis: All, Community, Trauma, (Other)? If external cause: All, All but adverse effects, Trauma, (Other)? If external cause: All, All but adverse effects, Trauma, (Other)? If other: what? If other: what?

References Injury Surveillance Workgroup. Consensus recommendations for using hospital discharge data for injury surveillance. Marietta (GA): State and Territorial Injury Prevention Directors Association; Injury Surveillance Workgroup. Consensus recommendations for using hospital discharge data for injury surveillance. Marietta (GA): State and Territorial Injury Prevention Directors Association; Centers for Disease Control and Prevention. Recommended framework for presenting injury mortality data. MMWR 1997;46 (No. RR-14) Centers for Disease Control and Prevention. Recommended framework for presenting injury mortality data. MMWR 1997;46 (No. RR-14) Hospital separations due to injury and poisoning, Australia Jesia Berry, James E. Harrison, March 2006, Australian Institute of Health and Welfare, Canberra. Hospital separations due to injury and poisoning, Australia Jesia Berry, James E. Harrison, March 2006, Australian Institute of Health and Welfare, Canberra.