Concept: External Cause of Injury Codes and Injury Categories

Introduction

This concept contains information on the external cause of injury codes from the International Classification of Diseases (ICD) coding systems and their use in MCHP research. This includes a brief description of external cause of injury codes available in the ICD-9-CM and ICD-10-CA coding systems, what codes are typically excluded in MCHP's definition of external cause of injury, access to the lists of external cause of injury ICD codes used in different MCHP research projects, and a description of the use of external cause of injury codes in specific research and direct access to this information through hyperlinks.

Identifying External Cause of Injury Using the ICD Coding Systems

External cause of injury codes are used to define environmental events, circumstances and conditions such as the cause of injury, poisoning, and other adverse effects related to injury morbidity and mortality. In both ICD-9 and ICD-10 coding systems, the external cause of injury / external cause of morbidity and mortality codes are intended to be used in conjunction with diagnoses codes from other chapters in the corresponding ICD coding system to clarify or specify the nature / cause of a diagnosis / condition.

In ICD-9 and ICD-9-CM, external cause of injury codes are often referred to as E-codes because they all began with the letter E. The E-codes range from E800 to E999. An associated variable named ECLASS can be used to classify external cause of injury diagnoses codes into specific categories. In ICD-10-CA, a different coding structure is used and the codes beginning with the letters V, W, X and Y are used to identify external causes of morbidity and mortality. NOTE: In more recent MCHP research, the range of ICD-10-CA codes includes V01-Y89.

The ICD codes can be found in the Hospital Abstracts data for injury hospitalization analysis and the Vital Statistics Mortality Registry data for injury mortality analysis. External cause of injury codes (E-codes) are not recorded with an "E" prefix in the Medical Services / Physician Claims data , therefore this data is not used to identify external cause of injury.

External Cause of Injury Categories (ICD-9-CM)

The following is a list of the major categories of external cause of injury codes using the ICD-9-CM coding system. NOTE: Over time, different categories have been used in different MCHP research projects.

In MCHP research, ICD-10-CA injury codes are usually converted to ICD-9-CM injury codes prior to grouping injuries into categories. This can be done using ICD Conversion Files.

The ICD-9-CM external cause of injury categories used in (Martens et al., 2010) are listed below. Each category relates to a specific range of ICD-9-CM E-codes that are part of the same category.


• Motor Vehicle Accidents
  
• Other Vehicle Accidents
  
• Poisoning
  
• Accidental Falls
  
• Accidents Caused by Fire and Flames
  
• Accidents Due to Natural and Environmental Factors
  
• Drowning and Submersion
  
• Choking, Suffocation and Constriction
  
• Sports Injuries
  
• Late Effects of Injury
  
• Suicide and Self-inflicted Injury (Violence to Self)
  
• Homicide and Injuries Inflicted by Others
  
• Accidents Caused by Foreign Bodies
  
• Struck by Objects, Caught Between Objects
  
• Accidents Caused by Machinery, Explosions, Electricity
  
• Overexertion, Strenuous Movements
  
• Injuries Due to War Operations
  
• Injuries Undetermined as Accidental or Purposely Inflicted
  
• Other Unspecified Accidents

Lists of External Cause of Injury Codes and Categories

Several MCHP research projects have developed and published a list of the specific external cause of injury-related diagnosis codes and categories used in their research. The lists developed for individual projects are available below, listed under each research project, with a direct hyperlink providing access to the list of codes and categories that were used.

Common Exclusions in MCHP Research

At MCHP, our research definition of external cause of injury usually excludes injuries resulting from misadventures during surgical or medical care, reactions or complications due to medical care, and adverse drug reactions. The specific ICD-9-CM and ICD-10-CA codes for these exclusions are:


• misadventures during surgical or medical care, ICD-9-CM codes E870-E876 (or ECLASS =10); ICD-10-CA codes Y60-Y69, Y88.1
  
• reactions or complications due to medical care, ICD-9-CM codes E878-E879 (or ECLASS =11); ICD-10-CA codes Y70-Y84, Y88.2, Y88.3
  
• adverse effects due to drugs, ICD-9-CM codes E930-E949 (or ECLASS =18); ICD-10-CA codes Y40-Y59, Y88.0

MCHP Research Investigating External Cause of Injury

The following provides a list of MCHP research projects that have investigated external cause of injury and provides a brief summary of each project and hyperlinks to the specific information available in the published report.

1. External Cause of Injury Related to Children

Several MCHP research projects investigate external cause of injury related to children. This includes the following deliverables:

2001 - Assessing the Health of Children in Manitoba: A Population-Based Study

In the Assessing the Health of Children in Manitoba: A Population-Based Study deliverable by Brownell et al. (2001), they investigated injury related to mortality and hospitalization rates for children. Injury events were defined as all inpatient hospital abstract records for Manitobans aged 0 to 19 with a value of ECLASS greater than 00 and not equal to 10, 11 or 18. Categories 10, 11 and 18 capture nearly all of the iatrogenic injuries, but some are unavoidably included in other categories. Category 8, Accidental poisoning by drugs, includes poisoning resulting from the wrong drug or an overdose of the correct drug given by a physician. It is impossible to determine how the drugs were administered from the ICD codes in Category 8, so this category was left in the definition even though it includes some injuries resulting from physician error.

The list of external cause of injury codes and categories used in this research is available in Table G.5: ICD-9-CM/ICD-9 External Cause of Injury Codes (E-codes).

For more information, please see Chapter 6: Health Status: Injuries in the deliverable. This chapter provides information on age and gender differences in injury, location (home, traffic, farm, workplace, hospital or other) of injuries, regional differences in injury rates by Regional Health Authority (RHA) and Winnipeg Community Areas (CAs), external cause of injury, injury and income levels, and correlations of injury rates with the healthiness (premature mortality rate) of populations within a region.

2004 - Manitoba Child Health Atlas

In the Manitoba Child Health Atlas on-line deliverable by Brownell et al. (2004), they investigated mortality and hospitalizations related to injuries in children for 1997 - 2001. Injury mortality was investigated for children aged 1-19 years by region and injury hospitalizations rates were investigated for children aged 0 - 19 years by region, socioeconomic status (SES) and by age category and age of mother at birth of first child.

The list of external cause of injury codes and categories used in this research is available in Table: ICD-9-CM/ICD-9 External Cause of Injury Codes (E-codes).

For more information, please see the section titled Childhood Injury in this on-line report.

2007 - Next Steps in the Provincial Evaluation of the BabyFirst Program: Measuring Early Impacts on Outcomes Associated with Child Maltreatment

In the Next Steps in the Provincial Evaluation of the BabyFirst Program: Measuring Early Impacts on Outcomes Associated with Child Maltreatment deliverable by Brownell et al. (2007), they investigated trends in injuries (particularly those associated with maltreatment) in the child population of Manitoba, before and after introduction of the BabyFirst program in 1999-2000, comparing indicators of child maltreatment in a 15-year time period before BabyFirst implementation and during the five years which followed.

Three measures of child abuse were implemented in children aged 18 years and younger: 1) hospitalization for or death due to injury [800-899.99, all E-codes except medical and surgical misadventure (E870-E879 and E930-E949)], 2) hospitalization for or death due to assault [E960-E969], and 3) hospitalization for or death due to maltreatment [E904, E967, E968.4]. For children most likely affected by the program, at ages three years and younger, the following two measures of child abuse were reported: 1) hospitalization for or death due to injury [800-899.99, all E-codes except medical and surgical misadventure (E870-E879 and E930-E949)], and 2) hospitalization for or death due to assault or maltreatment [E904, E960-E969, E988]. If a death occurred within 7 days of a hospitalization episode, it was counted as the same episode.

For more information, please read Chapter 5: Population-Based Evaluation of the BabyFirst Program that includes a description of the methods and the results including crude hospitalization rates per 1000, injury rates, assault rates and maltreatment rates for all children less than 19 years old, and injury rates and maltreatment rates for all children less than 4 years old, before and after the introduction of the BabyFirst program. A table summarizing the change in child outcomes after introduction of the BabyFirst program is also available.

2008 - Manitoba Child Health Atlas Update

In the Manitoba Child Health Atlas Update deliverable by Brownell et al. (2008), they investigated mortality and hospitalizations related to injuries in children. Injury mortality was investigated for children aged 0 to 19 years over two time periods: 1996-2000 and 2001-2005. Injury mortality rates were calculated by dividing the total number of injury deaths in each time period by the total population in the same time period and expressed per 100,000 children.

The document External Cause of Injury ICD Codes from Child Health Atlas Update contains a list of ICD-9-CM and ICD-10-CA external cause of injury codes that were used in the Manitoba Child Health Atlas Update deliverable by Brownell et al. (2008)

For more information, please read section 4.3 Injury Mortality that contains graphs of injury mortality rates by RHAs, Winnipeg Community Areas, Income Quintiles, Sex and Age Groups, and cause of death. Also included is a table that presents the top five causes of injury mortality by age groups.

Hospitalization for injury was investigated for children aged 0 to 19 years over two time periods: 1996/97-2000/01 and 2001/02-2005/06. Children who died from their injuries were not included in this analysis. For more information, please read section 5.4 Hospitalization for Injury that contains graphs of injury hospitalization rates by RHAs, Winnipeg Community Areas, Income Quintiles, Sex and Age Groups, and cause of death.

2012 - How are Manitoba's Children Doing?

In the How are Manitoba's Children Doing? deliverable by Brownell et al. (2012), they investigated child mortality and hospitalizations over two 5-year time periods: 2000-2004 and 2005-2009, for children aged 0 to 19 years.

Mortality information was found in the Vital Statistics Mortality Registry data and they found that injuries play a significant role - over 60% in both time periods. For more information, please read the section Causes of Child Mortality that contains graphs on causes of mortality and the top five causes by age group.

In this project, injury hospitalization was defined as a hospital episode with a "most responsible" diagnosis for injury and rates of injury hospitalizations were reported per 10,000 children. While investigating hospitalizations, they found that injuries represent one of the top five leading causes of hospitalization. Children who died from their injuries were not included in this analysis. For more information, please read Chapter 4: Safety and Security - Injury Hospitalizations that contains graphs on injury hospitalization rates by aggregate regions; trends by age groups and income quintiles; and changes in inequity over time using Lorenz curves.

The report also provides information on Causes of Injury Hospitalizations including graphs illustrating causes of injury hospitalizations and the top five causes of injury hospitalizations by age group over time.

Besides examining the causes of injury hospitalizations, they investigated the intent of injury. For this analysis, injuries were categorized as follows:


1. intentional (self-inflicted) - (ICD–9–CM E950–E969; ICD–10–CA X60–Y09, Y870–Y871);
   
2. unintentional (accidental) - (ICD–9–CM E800–E8699, E880–E9299; ICD–10–CA V01–X599);
   
3. undetermined (difficult to determine intent) - (ICD–9–CM E980–E989; ICD–10–CA Y10–Y34, Y872, Y899); and
   
4. other, such as legal intervention (ICD–9–CM E970–E978; ICD–10–CA Y35–Y36, Y890–Y891), operations of war (ICD–9–CM E990–E999), evidence of alcohol involvement determined by blood alcohol level (ICD–10–CA Y90), and evidence of alcohol involvement determined by level of intoxication (ICD–10–CA Y91)

The research compared intentional and unintentional injury hospitalizations. For more information, please read the section Intentional Versus Unintentional Injury Hospitalizations.

Additional information on injury hospitalization rates, cause of injury hospitalizations, and intentional and unintentional injury hospitalization rates can be found in the on-line data Appendix for this deliverable - see Chapter 04: Safety and Security for more information.

2. External Cause of Injury from a Regional Health Authority (RHA) Perspective

Several MCHP research projects focusing on the Regional Health Authorities (RHA) investigate external cause of injury for mortality and hospitalizations. This includes the following deliverables:

2003 - The Manitoba RHA Indicators Atlas: Population-Based Comparison of Health and Health Care Use

In The Manitoba RHA Indicators Atlas: Population-Based Comparison of Health and Health Care Use deliverable by Martens et al. (2003) they investigate and compare injury rates for mortality and hospitalizations by RHA for two different time periods.

The list of external cause of injury codes and categories used in this research is available in Table G.1: ICD-9-CM/ICD-9 External Cause of Injury Codes (E-codes).

In section 4.6 Injury Mortality Rates they present injury mortality rates per 1000 residents by RHA regions and the top causes of deaths and injury deaths in each region. The two 5-year time periods compared in this analysis are 1990-1994 and 1995-1999.

In section 9.6 Hospitalization Rates for Injuries they present injury hospitalization rates per 1000 residents by RHA and RHA Districts. The two 5-year time periods compared in this analysis included 1991/92-1995/96 and 1996/96-2000/01.

2009 - Manitoba RHA Indicators Atlas 2009

In the Manitoba RHA Indicators Atlas 2009 deliverable by Fransoo et al. (2009) they investigate and compare injury rates for mortality and hospitalizations by RHA for two different time periods.

The list of external cause of injury codes and categories used in this research is available in the section titled Injury Causes (Hospitalization and Death).

In section 3.8 Injury Mortality Rates they present injury mortality rates per 1,000 area residents per year by RHAs, RHA Districts and Winnipeg Neighbourhood Clusters. Mortality is based on the Vital Statistics Mortality Registry data. This includes all E–codes in the ICD–9–CM system (1996–1999) and the corresponding ICD–10–CA codes (2000–2005), except those codes for misadventures, reactions, complications, or adverse effects of medical, surgical or pharmaceutical treatments. Suicides were included in injury mortality rates. Rates are age- and sex-adjusted to the Manitoba population in the first time period.

In section 3.9 Causes of Injury Mortality they present the distribution of causes of injury deaths in ICD-9-CM categories for two different time periods: 1996-2000 and 2001-2005. Results are shown for Manitoba and the aggregate areas, but not by RHA due to the relatively small number of injury deaths by cause in smaller areas.

In section 7.11 Hospitalization Rates for Injuries they present injury hospitalization rates per 1000 residents by RHA, RHA Districts and Winnipeg Neighbourhood Clusters. The two 5-year time periods compared in this analysis are 1996/97-2000/01 and 2001/02-2005/06.

In section 7.12 Causes of Injury Hospitalizations they present the distribution of causes of injury deaths in ICD-9-CM categories for two different time periods: 1996/97-2000/01 and 2001/02-2005/06. The top 10 causes are shown for each time period for Manitoba and each aggregate area.

2013 - The 2013 RHA Indicators Atlas

In The 2013 RHA Indicators Atlas deliverable by Fransoo et al. (2013) they investigate several indicators that are based on diagnoses codes which are categorized using the ICD-10-CA chapters. One of these categories is "injury and poisoning". The indicators investigated in this report list the top 10 "causes" for each RHA and the province overall. For more information on these indicators and where the "injury and poisoning" category ranks within each RHA and the province overall, please read:


• section 3.2 Causes of Death - comparing 2002-2006 to 2007-2011
  
• section 3.4 Causes of Premature Death - comparing 2002-2006 to 2007-2011
  
• section 6.4 Causes of Physician Visits - comparing 2006/07 to 2011/12 - Note: these diagnoses were grouped by ICD-9-CM chapter.
  
• section 7.7 Causes of Hospitalization - comparing 2006/07 to 2011/12
  
• section 7.8 Causes of Hospital days Used - comparing 2006/07 to 2011/12

2019 - The 2019 RHA Indicators Atlas

In The 2019 RHA Indicators Atlas deliverable by Fransoo et al. (2019) they investigate hospital episodes for injury among children (ages 0-19), and report crude and adjusted rates by income quintiles, and by income sub-quintile.

For more information, see the section titled Hospital Episodes for Injury among Children in the online deliverable.

3. Other MCHP Research Involving External Cause of injury

Over time, there are several MCHP research projects that investigated external cause of injury for specific sets of cohorts. These include:

2002 - The Health and Health Care Use of Registered First Nations People Living in Manitoba: A Population-Based Study

In The Health and Health Care Use of Registered First Nations People Living in Manitoba: A Population-Based Study deliverable by Martens et al. (2002), they investigated and compared injury hospitalization rates and external cause of injury for hospitalizations for Registered First Nations (RFN) versus all other Manitobans.

The list of external cause of injury codes and categories used in this research is available in Table E-1: ICD-9-CM/ICD-9 External Cause of Injury Codes (E-codes).

In section 5.7.1 Injury Hospitalization Rates they present injury hospitalization rates per 1000 people by Tribal Council, for RFN versus all other Manitobans by RHA, and Off Reserve versus On Reserve RFN by RHA. The rates are based on five years of data - 1994/95 through 1998/99.

In section 5.7.2 Causes of Injury Hospitalization they present the percent of injury hospitalizations by injury category. These are presented in pie charts for RFN, All Other Manitobans, RFN On Reserve and RFN Off Reserve and are based on the same 5-year time period defined above.

2003 - Why is the Health Status of Some Manitobans Not Improving? The Widening Gap in the Health Status of Manitobans

In the Why is the Health Status of Some Manitobans Not Improving? The Widening Gap in the Health Status of Manitobans deliverable by Brownell et al. (2003), they investigated external cause of injury for mortality and hospitalizations of Manitobans by comparing two different 5-year time periods: 1985-1989 and 1995-1999. Injury mortality data were obtained through Vital Statistics Mortality registry data using the ICD-9 codes E800 to E999. Analysis of injury hospitalizations involved four cause-specific categories:


• falls (E880 to E888);
  
• motor vehicle crash (E810 to E825);
  
• violence - to self (E950 to E959) and by others (E960 to E969); and
  
• other - all remaining E-codes, excluding injuries resulting from misadventures during surgical or medical care and adverse drug reactions (E870 to E879, and E930 to E949).

For more information please read:


• the section titled Injury mortality that provides information on how much injury mortality changed throughout the study period comparing Winnipeg and non-Winnipeg residents and least healthy to most healthy and by age and sex categories.
  
• the section titled Injury that provides information on how much hospitalizations for falls, motor vehicle crash, violence and other injuries changed throughout the study period comparing Winnipeg and non-Winnipeg residents and least healthy to most healthy.

2010 - Profile of Metis Health Status and Healthcare Utilization in Manitoba: A Population-Based Study

In the Profile of Metis Health Status and Healthcare Utilization in Manitoba: A Population-Based Study deliverable by Martens et al. (2010) they investigated and reported injury mortality and injury hospitalization rates per 1000 residents, averaged over 10 calendar years, for Metis people compared to all other Manitobans.

The list of external cause of injury codes and categories used in this research is available in the section titled Injury Categories (External Causes, ICD-9-CM).

In section 4.3 Injury Mortality Rate they compared injury mortality rates by RHA and Winnipeg Community Area for Metis versus all other Manitobans, and for Metis people by Metis regions for 1997 to 2006. In section 4.4 Total Mortality by Cause and Injury Mortality by Cause they compared total mortality by cause for Metis and all other Manitobans for the period 2002 to 2006, and injury mortality by cause for Metis and all other Manitobans for the period 1997 to 2006. Appendix Tables 2.3 and 2.4 show the crude rates per 1000 for total mortality and injury mortality by RHA, Winnipeg Community area and Metis region.

In section 10.4 Injury Hospitalization Rate they compared injury hospitalization rates for Metis versus all other Manitobans by RHA and by Winnipeg Community Area, and for Metis people by Metis region for 2002/02 to 2006/07. In section 10.5 Injury Hospitalization Causes they compared the most frequent cause of hospitalization due to injury for Metis versus all other Manitobans for 2002/02 to 2006/07. Appendix Table 2.41 shows the crude rates per 1000 for injury hospitalizations by RHA, Winnipeg Community Area and Metis regions.

2012 - Health and Healthcare Utilization of Francophones in Manitoba

In the Health and Healthcare Utilization of Francophones in Manitoba deliverable by Chartier et al. (2012) they investigated and reported injury mortality and injury hospitalization rates for a Francophone cohort versus a matched cohort of other Manitobans.

The list of cause of injury codes and categories used in this research is available in Appendix 1: Definitions and Codes for Indicators - Causes of Injury.

In section 4.3 Injury Mortality they present rate ratios for injury mortality indicating how Francophones compare to a similar group of other Manitobans. In section 4.3.1 Causes of Injury Mortality they illustrate the major causes of injury mortality for Francophones compared to a similar group of other Manitobans. This analysis covered a 9-year period, from 1999 to 2007.

In section 10.3 Hospitalization for Injury they present rate ratios for injury mortality indicating how Francophones compare to a similar group of other Manitobans. This analysis covered a 5-year period, from 2004/05 to 2008/09. In section 10.4 Causes of Injury Hospitalization they illustrate the major causes of injury mortality for Francophones compared to a similar group of other Manitobans. This analysis covered a 1-year period, 2008/09.

2013 - Social Housing in Manitoba. Part II: Social Housing and Health in Manitoba: A First Look

In the Social Housing in Manitoba. Part II: Social Housing and Health in Manitoba: A First Look deliverable by Smith et al. (2013) they investigated and reported injury hospitalization rates per 1000 residents for a Social Housing cohort versus all other Manitobans. Analysis covered a 10-year period: 1999/2000 to 2008/2009.

The list of cause of injury codes and exclusions used in this research is available in Appendix Table A2.1: Indicator Definitions and Codes - Chapter 4: Morbidity and Mortality - Injury Hospitalizations.

In the section titled Hospitalizations for Injuries they present injury hospitalization rates by RHA and Winnipeg Community Area. In the section titled Causes of Injury Hospitalizations they present the top five causes of injury hospitalizations for social housing clients and all other Manitobans.

2015 -Long-Term Outcomes of Manitoba's Insight Mentoring Program: A Comparative Statistical Analysis

In the Long-Term Outcomes Of Manitoba's Insight Mentoring Program: A Comparative Statistical Analysis deliverable by Ruth et al. (2015) they investigated hospitalization rates and looked at injury hospitalizations as a sub-category of all hospitalizations. This research focused on the Insight program participants (see Insight Mentoring Program (IFASD) Data glossary term for more information).

The list of cause of injury codes and exclusions used in this research is available in Appendix Table 1.1: Technical Definitions of Indicators Used to Measure Long-Term Outcomes (Chapter 6) - 2. Hospitalizations - Injury.

In the section titled Hospitalizations they present hospitalization rates and relative risks for hospitalizations for different causes of hospitalizations (all (non-pregnancy), mental health, injury and other) for Insight participants before, during and after program participation, and compare hospitalization rates of the Insight participants to a comparison group.