Selecting a main injury from multiple causes of death “ISSUES”

1. Selecting a main injury frommultiple causes of death“ISSUES” ICE on Injury Statistics, Sept 2006 Limor Aharonson-Daniel , PhD Israel National Center for Trauma and Emergency Medicine Research Gertner Institute for Epidemiology and Health Policy Research for ICE on Injury Statistics working group

2. Head & Chest injury chest Head Head Chest 3. Select from among remaining injuries using severity ranking (e.g. Precedence list). Is “Head” = (“Head & Chest”)? Is “Chest” = (“Head & Chest”)? yes no Select “head & chest” Good

3. For these cases, we should consider applying Multiple Injury Profile Concepts • The population of patient injuries: • Patients with - • One injury only • Multiple where one injury has clear precedence in causing death • Multiple where no ‘one injury’ has precedence 4.6% of patients in the ‘TBI row only’ died 6.5% of patients in the ‘chest row only’ died 14.7% of patients in both rows died

4. The study simulated selection by precedence and showed what proportion of each body region was: Isolated, Selected by precedence list, would be additional if multiple injuries were used rather than primary injury. • Differences were mostly in external and face => minor • In Head, Chest and Abdomen the proportion of diagnoses ranked “in” by precedence list is larger than their proportion by isolated injuries. • Based on this data, I thought we should consider a multiple code: • A code for Head & chest • A code for Head & Abdomen • Elimination of trivial injuries and superficial injuries should prevail as suggested in current MRG guidelines

5. Arguments against using a new multiple code • Would be an exception to the guideline/principles of the ICD • combination code would be less specific and if available it might be chosen over the individual codes in the data collection phase

6. Arguments against selecting a main injury by precedence • We lose information • Sometimes precedence just can’t be forced: • Certain combinations are “killers” while their components are not - • Selecting in these cases creates a false presentation • SRRs are affected by additional injuries*

7. Possible solution: Create an indicator / flag as an optional addition to ICD codes. A tick mark that could be the equivalent of “the first two authors contributed equally to this manuscript” meaning “this case is not suitable for selection of a primary cause use alternative methods”. Arguments for this approach: It would enable applying multiple injury approach where needed It would not change current coding guidelines It can serve as a “warning” where this is all you will get

9. Method for eliminating unspecified injuries Example: S26.9 Injury of heart, unspecified Injuries occurring simultaneously (i.e. sequential order is not inherent) Consideration of external cause in determining main injury if indicates something about nature Example: External cause: car crash Main injury: poisoning? ICE working group concerns with current recommendations ☺ MIP Example: Car crash with multiple specified injuries on each line of death certificate ☺ poisonings, drowning, suffocation and fire/flames.