Multiple cause of death data and poisoning

1. Multiple cause of death data and poisoning Cleo Rooney & Multiple cause of injury workgroup April 2001

2. Discussions • Uses of multiple cause coded mortality data and selecting main injury • explaining differences in underlying cause data • between places, times • ‘correcting’ unspecified underlying cause • Difficulties classifying poisonings with multiple substances • Changes in ICD-10 and comparability studies

3. Main injury in mortality data • Encourage publication of multiple cause data- ~ 15 countries / 65 contribute data to WHO • ICD-9 precedence list provided for choosing main injury • Skull Fracture and broken neck • Internal Injury of chest, abdomen, pelvis • Fracture of face, spine, trunk • Other head injury, open wounds of neck&chest, amputation of limbs, spinal cord lesion • Fracture of limbs • Burn • Other

4. Main Injury in ICD-10 • ICD-10 • Sequence and rules provided as for other deaths • If no sequence, choose first mentioned • Combination codes could be selected • Problems: • In injury events there may not be a time sequence • Do certifiers know sequence matters? • Loss of specificity/detail if use combination code • Selection rule is not WHO mandated

5. Israel method of choosing main injury • Presented way of classifying injury morbidity data by severity (AIS), nature and body region • Allowed main / most serious injury selection for trauma registry / hospital admission • Requires ICD codes and AIS scores • ? use to test selection of main injury

6. Number of injury codes per deathCox, Rooney, Fingerhut ICE 2000

7. Proposed analyses of multicause • Compare main injury chosen by • Precedence list • First listed • ICD-10 rules • Combination codes • Diagnostic matrix • Redistribute ‘unspecified accident’ deaths using injury information

8. Injury deaths of unspecified mechanism by ICD-9 main injury precedence listCox, Rooney, Fingerhut ICE 2000

9. Countries that submitted multicause data in ICD-9 • USA • Sweden • Scotland • E&W • More volunteers?

10. Changes in coding injury deaths in ICD-10 • Main Injury • No precedence list for injuries • Combination codes for injuries • Underlying cause • Fracture unspecified cause > unspecified accident • Fractures / falls can be due to osteoporosis • Rule 3

11. Comparability studies -multicountry • Injury deaths ratios • All injuries • By matrix groups • Differences between countires • ?pooled ratios across countries • Are ICD-10 data more comparable? • Israel and US results yesterday- • broadly reassuring

12. Deaths from falls, fractures and osteoporosis • Comparability ratios v different in USA, Israel and Sweden • E887 > unspecified accident • can be due to osteoporosis • rule 3 and pneumonias • Quantify net change by country • ? Differences in each effect • certification or coding

13. Comparability study data • Countries which can contribute • Send copies of comparability study reports • individual level data • tabulated data / special analyses • Volunteers?

14. Poisonings • c50% of deaths have more than one substance • Can’t identify which of several substances primarily responsible for death • combination codes may be confusing for data users • need finer classification of substances • meaningful classification for clinicians and toxicologists as well as epidemiologists

15. Multi-substance poisonings • Main injury and underlying cause • combination codes • Multicause codes • Text of certificate • more detail • ?? How to present it

16. Deaths from drugs and poisonings[poisonings 960-989, abuse & dep 304, 305] • Number of deaths alone in combination by substance • all substances x y • heroin/morphine A B • paracetamol C D • antidepressants E F

17. Projects for Montreal • Compare selection of main injury by different methods • Redistribute unspecified accident deaths using injury codes • Collate comparability study data ICD-9/ 10 across participating countries • changes in classification of deaths from falls, fractures and osteoporosis • ? Poisoning later ? volunteers