US ICD9ICD10 Comparability for Injury

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US ICD-9/ICD-10 Comparability for Injury
Margaret Warner, Ph.D. Office of Analysis and
Epidemiology ICE on Injury Statistics, Vienna,
June 2004
Centers for Disease Control and
Prevention National Center for Health Statistics
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The U.S. ICD-9/ICD-10 Comparability Study

• Purpose
• To measure the effect of ICD-10 on cause of death
  trends
• To provide a check on the ICD-10 automated coding
  systems

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The U.S. ICD-9/ICD-10 Comparability Study

• Preliminary results published in 2001
• National Vital Statistics Reports vol 49 no 2
• based on about 80 percent of 1996 mortality
  records
• Final comparability data include all 1996
  multiple cause mortality
• ICD-10 information is available for more than 99
  percent, some known errors in the data file
• File will be available to public

4
Products from NCHS

• Produce a final report on ICD-9/ICD-10
  comparability for all deaths (future)
• Maintain (in-house) updated version of file with
  corrections and modifications
• For injury
• CR are available for cells and marginals of EC
  matrix
• Comparability for specific nature of injury codes
  (e.g. TBI)

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Development of Comparability EC Matrix

• Majority of comparisons on cells and marginals of
  EC matrix
• ICD-10 matrix developed to be consistent with
  ICD-9 matrix where possible
• Some movement of codes based on changes to ICD-10
  (e.g. MVTC) and updates (e.g. drowning)
• For trends, ICD-9 External cause matrix adjusted
  to match ICD-10 matrix

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Comparability ratios different from 1 expressed
as percent
60
50
40
30
Struck by, against
Unspecified
Suffocation
20
Other specified NEC
Natural/Environ
Poisoning
Other spec
Machinery
Cut/pierce
Drowning
10
MVTC
0
-10
-20
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Example Falls

• CR 1.0015 or .2 increase
• Total ICD-9 11,483
• Total ICD-10 11,500
• Agreement 10,840 89
• Outflows (ICD-9 not ICD-10) 643 5.3
• Inflows (ICD-10 not ICD-9) 660 5.4

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More injuries in ICD-10 than ICD-9

• All injuries, Comparability Ratio 1.0159
• 2,391 more deaths with underlying cause of injury
  in ICD-10 than ICD-9
• In ICD-10, 33 of 2,391 were classified as
  unintentional suffocations
• In ICD-9, 17 of 2,391 were classified as
  Pneumonia
• Change in selection rules for underlying cause

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Conclusion

• On web in near future-- Death and death rates for
  ICD-9 comparability modified EC matrix by age and
  sex
• Examples of how to deal with trend data in many
  publications from NCHS (e.g. Health, US)
• Guidelines with examples on how to do analysis
  available
• Lots more work here!!!