Hospital Separations

1. 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

2. 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?

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

4. Methods – Analysis overview • 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 • Compare the groups of records retrieved using the different approaches • Total numbers of records • Numbers of particular types of injuries, classified by external cause

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

6. More thanks • Africa Olive Kobusingye • South Africa Richard Matzopoulos • Japan Tatsuhiro Yamanaka • European Union Maria Segui-Gomez Information from 11 countries and the EU study available for analysis

7. 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

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

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

10. 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

11. Methods – Dataset • Used Hospital Morbidity Database from the Canadian Institute for Health Information • Initial selection: • All acute care separations from one Canadian province for fiscal year 2000-01. • N=126,217.

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

13. Externalcause on record Present Not present A B XVII - Injury & poisoning 10,273 8,254 (56%) 2,019 (14%) ICD-9 Diagnosischapter C C D 4,499 Other 4,499 (30%) 0 14,772 12,753 2,019 14,772

14. Total records retained, by approach

15. Percentage of records retained where diagnosis is not from the injury chapter 0 0 0

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

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

18. Selected unintentional external causes:Adverse effects 0 0

19. Selected external causes:All records, Unintentional injuries, falls

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

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

22. Selected unintentional external causes:Suffocation, Other foreign bodies 0 0

23. Selected external causes:Other intents

24. Conclusions • 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 • External cause approaches generally yield more records than the injury diagnosis approaches

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

26. References • Injury Surveillance Workgroup. Consensus recommendations for using hospital discharge data for injury surveillance. Marietta (GA): State and Territorial Injury Prevention Directors Association; 2003. • 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 2001-02. Jesia Berry, James E. Harrison, March 2006, Australian Institute of Health and Welfare, Canberra.