Injury Data and NCHS

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Injury Data and NCHS
Lois A. Fingerhut NCIPC Conference, May 2005
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Focus for this morning

• NCHS injury-related web pages
• ICD-9 to ICD-10 comparability file
• Frameworks for presenting data
• Poisoning- a recent example of a question of
  definition
• Injury severity- new collaborative work

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Our new injury website pages

• One stop shopping for questions/presentations/publ
  ications regarding NCHS surveys and data sets
  that have an injury component
• Links to non-NCHS sources (eg WISQARS)
• Up-to-date information on the International
  Collaborative Effort (ICE) on Injury Statistics

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                  National Databases
Injury Mortality DataFrom the National Vital
Statistics System Data Source Mortality-Injury
Summary Injury Death Codes Publications
Presentations Tabulated Data Public Use
Data  Data Tools Query Systems Related Links
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ICD-9 to ICD-10 Comparability

• A Guide to State implementation of ICD-10 for
  mortality ( 2000)
• Comparability reports going back to ICD-4 to
  ICD-5
• ICD-9 t o ICD-10 detail
• Downloadable file on ICD-9 to ICD-10
  comparability study
• Full file documentation
• SAS statements

http//www.cdc.gov/nchs/datawh/statab/unpubd/comp.
htm A20guide20to20state20implementation20of
20ICD-10
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ICD-10 on the WHO Website

• WHO Family of International Classifications
• http//www.who.int/classifications/en/
• There is a complete online version of ICD-10

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Frameworks for presenting data
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Frameworks for presenting data

• External causes
• ICD-9 and ICD-9 CM external cause code matrices
• ICD-10 external cause code matrix
• Injury Diagnoses
• ICD-9 CM Diagnosis codes Barell Matrix
• ICD-10 injury diagnosis code matrix

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External cause matrix-basic structure
Intent of injury Intent of injury Intent of injury Intent of injury Intent of injury Intent of injury
Mechanism Unintentional Suicide Suicide Homicide Undeter-mined Other
MV-traffic
Cut
Firearm ICD-9, ICD-9-CM and ICD-10 External cause codes ICD-9, ICD-9-CM and ICD-10 External cause codes ICD-9, ICD-9-CM and ICD-10 External cause codes
Poisoning ICD-9, ICD-9-CM and ICD-10 External cause codes ICD-9, ICD-9-CM and ICD-10 External cause codes ICD-9, ICD-9-CM and ICD-10 External cause codes
Struck by/ against
Suffocation Etc..
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External Cause of Injury Mortality Matrix (ICD-10)
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Injury deaths by matrix 2002
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New International Recognition!

• The Mortality Reference Group (MRG), the group
  charged with refining and recommending changes to
  the ICD formally recommended
• Publish External Cause of Injury Mortality
  Matrix data in addition to standard WHO
  tabulations to facilitate statistical analysis
• Source www.who.int/classifications/network/en/ic
  elandexecutifsummary.pdf

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Barell Matrix-basic structure
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Barell matrix a standard for presenting injury
morbidity data

• See ICE webpage for full description of the
  matrix
• www.cdc.gov/nchs/about/otheract/ice/barellmatrix.h
  tm
• Barell V, Aharonson-Daniel L, Fingerhut LA,
  MacKenzie EJ, et al. An introduction to the
  Barell body region by nature of injury diagnosis
  matrix.
• Injury Prevention 2002891-6.
• National Hospital Discharge Survey 2002 Annual
  Summary With Detailed Diagnosis and Procedure
  Data (table 24)
• www.cdc.gov/nchs/data/series/sr_13/sr13_158.pdf

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ICD-10 Injury Mortality Diagnosis Matrix
ICD-10 S T codes
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Head and neck all Traumatic brain injury Other
head Neck Head and Neck Spine and upper
back Spinal cord Vertebral column Torso Thorax
Abdomen Pelvis and lower back Abdomen, lower
back pelvis Trunk, other Extremities Upper
extremities Hip Other lower extremities Not
classifiable by site Multiple body regions System
wide Unspecified
ICD-10 Body region of injury categories for
mortality
Level 1
Level 2
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Additional detail is available, butnot
necessarily appropriate for mortality

• For example, Level 2- Other lower extremities
  can be disaggregated to Level 3 categories
• Thigh L3-31
• Hip Thigh L3-32
• Upper Leg and thigh L3-33
• Knee L3-34
• Lower leg L3-35
• Foot L3-36
• Ankle L3-37
• Other and multiple ankle and foot L3-38
• Toes L3-39
• Other lower limb L3-40

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ICD-10 mortality Nature of injury Categories
Fractures Dislocation Internal organ
injuries Open wounds Amputations Blood
vessels Superficial contusion Crushing Burns Eff
ects of foreign body Other effects of external
causes Poisoning Toxic effects Multiple
injuries Other specified Sprain or strain Muscle
and tendon injuries Nerve injuries Unspecified
Level 1
Level 2
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Total and any mentions of injury diagnoses by
body region 2002
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Total and any mentions of injury diagnoses by
nature of injury 2002
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Injuries mentioned in MVT deaths (44,065 deaths
and 70,684 injuries) by body region and nature of
injury US, 2002
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Under discussion..How should we define poisoning?
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Definitional issues poisoning mortality

• ICD-9 vs ICD-10
• Underlying cause external cause codes
  (ICD-10 X Y codes)
• ICD-10 Multiple cause T codes for substances
• Mental health F codes
• Nondependent abuse
• Dependent abuse
• Alcohol intoxication (not included here)
• Adverse effects codes (not included here)

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ICD definitions of drug poisoning
ICD-10
Nondependent abuse of drugs 305.2-.9 F11-16, 18-19 (not .2)
Dependent abuse 304 F11-16,18-19(.2)
Unintentional E850-E858 X40-X44
Suicide E950(.0-5) X60-X64
Undetermined E980(.0-.5) Y10-Y14
Homicide E962.0 X85
Alcohol intoxication 305.0 F10.0
ICD-9
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ICD-9 vs ICD-10Substance selection

• ICD-9 underlying cause codes for poisoning more
  specific than ICD-10 codes
• ICD-10, to get specific substances
• Literals from the death certificate
• Code the multiple cause data

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ICD mortality coding varies by country
ICD-9-UCOD ICD-10-UCOD Substance-specific
England and Wales 1990-2000 2001-2002 Literals from text files
Canada 1990-1999 2000-2002 From under-lying cause
United States 1990- 1998 1999-2002 Multiple cause coding
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Drug poisoning death rates US, 2002
Deaths per 100,0000 pop
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Leading specified substances mentioned in drug
deaths for 35-54 year olds US, 2002

• Cocaine T40.5 25
• Other specified opioids T40.2 21
• Antidepressants T43.0-T43.2 11
• Alcohol T51 11
• Carbon Monoxide T58 8
• Heroin T40.1 10
• Benzodiazepines T42.4 9
• Methadone T40.3 10

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Next Steps

• In 2003, the MRG recommended to the URC of the
  WHO that new rules will apply in January 2006 to
  the underlying cause coding of certain ICD codes
  from Mental and Behavioral Disorders (F10-F19)
• If there is any mention of an external cause on
  the certificate, the code will be to the external
  cause rather than MBD code
• Codes in the F10-F19 range with a 4th digit of .0
  (acute intoxication) will be coded to poisoning
  codes in the external cause of poisoning section

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Injury Severity

• Some new considerations for national data
• Acknowledging many of these next slides from
• Dr. Ellen MacKenzie, Johns Hopkins University

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September 2004 Meeting

• Meeting convened at NCHS bringing together
  national and international experts in the area of
  injury severity scoring
• Why? Because the current standards AIS and
  ICDMAP are proprietary and many believe that
• There are nonproprietary alternatives
• They should not be proprietary any longer

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INJURY SEVERITY Alphabet Soup
ASCOT
APS
IIS
CRAMS
ICISS
TRISS
ISS
APACHE
AIS
RTS
GCS
AP
EM
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Injury Severity IndicesMajor Areas of
Application

• Triage
• Prognostic Evaluation
• Research and Evaluation
• Clinical Research
• Systems Evaluation
• Surveillance and Epidemiology

EM
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The Abbreviated Injury Scale (AIS)

• A classification of injuries based on anatomic
  descriptors
• A severity score ranging from 1 (minor) to 6
  (maximum injury, virtually unservivavle) assigned
  to each injury

EM
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Scores are subjective assessments assigned by a
group of experts and implicitly based on four
criteria

• Threat to life
• Permanent Impairment
• Treatment Period
• Energy Dissipation

EM
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AIS

• Currently, most widely used severity score based
  on anatomic descriptors
• Official injury data collection tool of
  NHTSA crash investigation teams
• Developed in 1971 5th revision to be published
  in 2005

EM
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Using AIS for Multiple Injuriesfor predicting
survival

• Injury Severity Score (ISS)
• The New Injury Severity Score (NISS)
• The Anatomic Profile (AP) and the Anatomic
  Profile Scale (APS)

EM
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ICD-Based Measures of Injury Severity

• ICD to AIS Conversion
• ICISS Family of Measures

EM
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ICDMAPICD-CM to AIS Conversion

• Converts ICD-9CM coded discharge diagnoses into
  AIS injury descriptors, AIS scores and computes
  ISS, NISS, APS
• Conservative measure of injury severity - refer
  to as ICD/AIS scores
• Limitations identified revision needed

EM
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ICISS

• Based strictly on ICD rubrics
• The ICISS score for a given patient is the
  product of the survival risk ratios (SRRs)
  associated with each ICD diagnosis
• SRRs are calculated by dividing the number of
  survivors among patients with a specific ICD by
  the total number of patients with that ICD code

EM
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Refining the ICISS

• Computation of SRRs based on multiple trauma
  patients or patients with single injuries?
• Database used for calculation of SRRs
• Trauma centers only vs. population based ?
• Include ALL deaths, only deaths in ED or hospital
  or only in-hospital deaths ?
• Registry data vs. administrative data ?
• Regional/local vs. national data?
• Computation of ICISS use product of SRRs or
  lowest SRR?

EM
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To think about.

• Need to keep in mind the application severity
  (case mix?) adjustment for use with hospital
  discharge data (HDD) also mortality data,
  ambulatory care encounter data ?
• By necessity must be based on ICD (but what do
  we lose how good can we get without physiology
  ?)
• Age, gender, co-morbidities and mechanism are
  important in case mix adjustment and all are
  measurable using HDD

EM
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and . . .

• Are we just interested in measures that predict
  mortality ?
• Need to carefully consider the overall
  advantages (current and future) of the AIS
  classification in any recommendations
• What are implications of the 2005 revision of
  the AIS and the ICD-10 (CM??)

EM
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What we know

• National trends in injury-related hospital
  discharges and emergency dept. visits reflects
  utilization, but not differences in injury
  severity
• ICD codes alone cannot distinguish severity among
  injuries
• ICD-10 has provided no real guidance on how to
  select a main injury among multiple cause of
  injury mortality data

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The practical problems

• ICD-9 CM is still being used for coding morbidity
  data annual updates to CM continue
• Most recent version of ICDMAP doesnt recognize
  new codes
• ICD-10 CM doesnt yet have an implementation date
  and there is no new ICDMAP based on ICD-10
• ICD codes used for mortality data often lack
  specificity

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What was discussed

• Strengths and weaknesses of different severity
  scales
• Solutions for administrative data acknowledging
  the limitations of the source data (e.g.,
  non-specific coding, changes in admission
  practices)
• Can we measure threat to function as well as
  threat to life?

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What we would have liked to accomplish

• Agree upon a measure of injury severity to add to
  NCHS survey data
• Incorporate a method to identify the main
  injury in mortality and add it to the mortality
  file
• Recommend a standard measure to users of
  administrative databases (e.g., Statewide
  hospital discharge data sets)

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Where might these measures be used?

• Tracking Departments Healthy People Objectives
• CDC Futures Initiative- Health Protection Goals
• NCHS reports Health, United States
• Injury Chart book(s)
• Statewide trauma and general injury databases

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NCHS Data Sources for Injury Severity

• National Hospital Discharge Survey
• National Hospital Ambulatory Medical Care
  Survey-ED component
• National Health Interview Survey ??
• Mortality data from vital statistics

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Other Federal Sources

• Agency for Health Care Research and Quality
• Medical Expenditure Panel Survey (MEPS)
• Healthcare Cost Utilization Project (HCUP)
• Nationwide Inpatient Sample (NIS)
• State inpatient databases (SID)
• State emergency dept databases (SEDD)
• http//www.ahrq.gov/data/hcup/

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Discharge Disposition for injury diagnoses NHDS,
2002
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Survival Risk Ratios (SRRs) NHDS, 2002
Discharged alive all discharges
Based on all 7 dx fields Ordered by of
discharges
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1st listed injury dx by nature of injury grouped
by AIS NHDS, 1999-2002
of 1st listed dx AIS 1-9
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NHAMCS- ED Percent hospitalized by nature and
body region of injury, 1999-2002
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NHIS severity variables in addition to nature
of injury

• Days out of school
• Days out of work
• Hospitalized
• Any limitations of activity

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Mortality data from NVSS

• ICD-10 uses all digits up to 20 listed
  diagnoses
• For 2001, range (0-15 injuries listed)
• 1 injury listed 65 of deaths
• 2 injuries 22
• 3 injuries 8
• 4 -15 injuries 4
• How can we select the most severe injury?
• Do we need to include underlying cause of death?

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So

• Most hospitalized injuries are not fatal
• Most ED visits dont result in hospitalization
• Too many mortality records lack detailed
  diagnosis codes

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Optimism.

• SRRs and ICISS can be readily calculated from
  hospital discharge data we are creating a file
  with them that will be on the web
• AIS could theoretically be added also to hospital
  discharge data file once it is in public domain
  and ICDMAP is updated
• Main injury (method yet to be determined) will be
  added to mortality file

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Consensus (well almost.)

• AIS and ICDMAP should be maintained and updated
• BOTH should be non-proprietary
• ICISS is a useful alternative to the current
  non-updated ICDMAP
• Statistical methods need continued evaluation and
  improvement
• Lowest SRR may be better than ICISS

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Visit us at www.cdc.gov/nchs/injury.htm
Email us at nchsinjury_at_cdc.gov