Documentation

Injury MICA

ICD-9 codes

Record Selection for All Injuries

The injuries in this MICA are those recorded by hospitals for their emergency room patients and inpatients, as reported by the Missouri Department of Health and Senior Services Patient Abstract System (PAS).

The causes of the injuries are defined according to the external-cause codes (E codes) of the International Classification of Diseases-9^th Revision-Clinical Modification (ICD-9-CM). This coding system is used by hospitals to record the injur ies and diseases of their patients. The E-codes and diagnosis codes used to define injury causes and determine whether a patient’s records should be included in this MICA are given below.

Records were selected for this MICA if there was a diagnosis code of 800-995 in the first diagnosis field and the injury was not a late effect according to either the principal diagnosis (905-909)code or the E-code (929,959,969,989,999). Medical misadventures (E870-E879) and adverse effects of drugs(E930-E949) were also excluded. Not all causes of injury are available for display in the MICA. The particular causes that can be displayed were chosen based on their frequency of occurrence and their intere st to the public health community.

Injury Matrix

This MICA is structured to follow the Intent-by-Mechanism matrix recommended by the Centers for Disease Control. The matrix categorizes all E-codes according to a mechanism of injury (firearm, poison, etc.) and four intentions (assault: intent to i njure others; self-injury: intent to injure oneself; unintentional: accidental or no intent to hurt anyone, and intent undetermined: intention cannot be determined). For example, firearms can be used with the intent of injuring oneself or others or they c an injure people accidentally. Selecting Mechanism as the row variable and Intent as the column variable (or vice versa) will result in a table showing the frequencies of each mechanism according to each intention. If just the mechanisms are selected for display in a table, the user should understand that the mechanisms will encompass all intentions (unless an intention is selected as a qualifying variable for the table).

Special Problems

Abusive behavior - Abusive behavior, a type of assaultive behavior, does not fit very will into the intention-mechanism structure. Ideally, abusive behavior, like the other intentions, could be categorized by which mechanism was used--strikin g someone, cutting someone, etc.--but the E-codes are not structured this way, and abuse can only be categorized by the types of abusive behavior--spouse abuse, child abuse, etc. If abuse had been included in the MICA as a category of assault, it would ha ve given the impression that a user could develop a table with abuse as the column variable and mechanism as the row variable and expect to see firearm, cutting, etc., as ways of inflicting abuse, when in fact all the rows would be blank. For this reason abuse was included as a mechanism rather than an intention.

A further complication with the Abuse/Neglect/Rape category is that a record may fall into more than one category of abuse depending on the patient's age and the E-codes and diagnosis codes on the record. For example, some records had both an E-code fo r spouse abuse and a diagnosis code for sexual abuse. Records with multiple codes were categorized according to the following priority: spouse abuse, sexual abuse, rape, shaken baby, physical abuse, neglect.

Codes for some forms of abuse were not added to the ICD-9-CM manual until the mid 90's; therefore frequencies for the abuse categories are especially low prior to 1997. Even since then it is likely that the various forms of abuse are underreported.

Motor Vehicle Crashes - E-coding of injuries due to motor vehicle crashes is also somewhat confusing. Crashes are grouped by E-codes into motor vehicle crashes on a trafficway (E-codes 810-819), nontrafficway motor vehicle crashes, such as in a p arking lot or driveway(E-codes 820-825), and nonmotorized road vehicle crashes, such as those involving bicycles or animals being ridden (E-codes 826-829), which can travel on a trafficway or nontrafficway. Within each of these groups the E-codes identify the injured person, as in motor vehicle driver, bicycle driver, pedestrian, etc. Within the nonmotorized road vehicle category, the two injured groups of most interest are pedestrians and bicycle drivers; to keep the information on bike riders and pedest rians together as much as possible, these two groups were included as drilldown groups in the Motor Vehicle, Other category. Drilling down on the latter category therefore yields four non-traffic motor vehicle subgroups and two nonmotor vehicle subgroups: Bicyclist-nontraffic, Pedestrian-nontraffic, Other Vehicle-nontraffic, Motorcyclist-nontraffic, Other Person-nontraffic, Pedestrian-nonmotor vehicle, and Bicyclist-nonmotor vehicle. Thus the Bicyclist-nontraffic and Pedestrian-nontraffic subgroups would include bikers and pedestrians injured by ATV's, for example; the Pedestrian-nonmotor vehicle and Bicyclist-nonmotor vehicle subgroups would include bike riders and pedestrians not injured by motor vehicles, as with a person who is injured by hitting his/ her head on the road after falling off a bike. A third group of injured bicyclists and pedestrians are those who are hit by motor vehicles on a trafficway, and their totals are given by drilling down on the Motor Vehicle Trafficway category.

Multiple Records. The inpatient records and emergency room records are designed to be mutually exclusive in the PAS system. If a person is admitted to the hospital through the emergency room, the inpatient record but not the E/R record should be included in the PAS. Only if the person is treated in the E/R and released should the E/R record be included in the PAS. Due to the size of this data system and the resulting editing challenge it represents, a small number of patients will have both an E/R and inpatient record for the same hospital stay. Additionally, patients who return to the hospital for follow-up treatment will also have more than one E/R or inpatient record for an injury episode. The number of injury records is thus somewhat mo re numerous than the number of injury episodes and patients. An attempt to separate records from persons for the 1999 injury data for this MICA indicated that the number of patients was 10 percent less than the number of records for the combined E/R and i npatient records. This percent was fairly similar across mechanisms and intents; the largest difference in the number of patients and the number of records among mechanisms was 13% for overexertion, while the largest difference for intentions was 16% for Intent Undetermined. (These percents should be considered estimates, since a small number of records do not have patient name on them, and because it is impossible to determine whether a person who has two or more records with the same E-code has been tre ated for separate injury incidents or has visited hospital(s) multiple times for the same injury incident.)  

Injury E-Codes Following are the ICD-9-CM E-codes and diagnosis codes used to define the causes of injury. For more detail on these categories, please consult a current ICD-9-CM manual or contact us.

Intent E-codes:

Unintentional'800'-'948'
Self Injury '950'-'958'
Assault (including '960'-'978','990'-'998'legal intervention and war)
Undetermined All Other

MechanismE-codes:

Cut, Pierce '956 ','9560','966 ','9660','9662','974 '-'9749','920 '-'9209','986 '-'9869'

Drowning,Submersion '830 '-'8309','832 '-'8329','910 '-'9109', '984 '-'9849','964 ','9643','954 '

Fall,Jump '957 '-'9579','880 '-'8869','888 '-'8889','987 '-'9879','9681'

Fire,Burn '890 '-'8999','924 '-'9249','9881'-'9882','9581','9582','9587','990 '-'9909', '9887','961 ','9680','9683','9614'

Firearm '922 '-'9229','965 '-'9654','970 ','9709', '9850'-'9854','9910'-'9913','9550'-'9554'

Machinery'919 '-'9199'

Motor Vehicle Traffic '810 '-'8199','9885','9585','9685'

MotorVehicle Traffic Drilldown:
car, truck, etc., occupant '8100'-'8101','8110'-'8111','8120'-'8121',
'8130'-'8131','8140'-'8141','8150'-'8151',
'8160'-'8161','8170'-'8171','8180'-'8181',
'8190'-'8191'
motorcyclist '8102'-'8103','8112'-'8113','8122'-'8123',
'8132'-'8133','8142'-'8143','8152'-'8153',
'8162'-'8163','8172'-'8173','8182'-'8183',
'8192'-'8193'
bicyclist '8106','8116','8126','8136','8146','8156',
'8166','8176','8186','8196'
pedestrian '8107','8117','8127','8137','8147','8157',
'8167','8177','8187','8197'

Motor Vehicle, Other '8206','8216','8226','8236','8246','8256',
'8260','8270','8280','8290',
'8261','8271','8281','8291',
'8207','8217','8227','8237','8247','8257',
'820 '-'8205','821 '-'8215','822 '-'8225',
'823 '-'8235','824 '-'8245','825 '-'8255',
'8208'-'8209','8218'-'8219','8228'-'8229',
'8238'-'8239','8248'-'8249','8258'-'8259',
'826 ','8262'-'8269','8272'-'8279',
'828 ','8282'-'8289','8292'-'8299'

Motor Vehicle, Other Drilldown:
bicyclist,non-traffic '8003','8013','8023','8033','8043','8053',
'8063','8073','8206','8216','8226','8236',
'8246','8256'
pedestrian,non-traffic '8002','8012','8022','8032','8042','8052',
'8062','8072','8207','8217','8227','8237',
'8247','8257'
other vehicle(car,ATV, etc) occupant '8200'-'8201','8210'-'8211',
'8220'-'8221',
'8230'-'8231','8240'-'8241',
'8250'-'8251'
motorcyclist,non-traffic '8202'-'8203','8212'-'8213','8222'-
'8223','8232'-'8233','8242'-'8243',
'8252'-'8253'
other person, non-traffic '8204'-'8205','8214'-'8215','8224'-'8225',
'8234'-'8235','8244'-'8245','8254'-'8255',
'8208'-'8209','8218'-'8219','8228'-'8229',
'8238'-'8239','8248'-'8249','8258'-'8259'
pedestrian injured, non-motor vehicle '8260','8270','8280','8290'
bicyclist injured, non-motor vehicle '8261','8271','8281','8291'

Other Transport '8002','8012','8022','8032','8042','8052',
'8062','8072',
'8003','8013','8023','8033','8043','8053',
'8063','8073',
'800 '-'8001','801 '-'8011','802 '-'8021',
'803 '-'8031','804 '-'8041','805 '-'8051',
'806 '-'8061','807 '-'8071',
'8008'-'8009','8018'-'8019','8028'-'8029',
'8038'-'8039','8048'-'8049','8058'-'8059',
'8068'-'8069','8078'-'8079',
'831 '-'8319','833 '-'8459',
'9586','9886'

Weather, Wildlife '900 '-'9099','9280'-'9282','9883','9583'

Weather and Wildlife Drilldown:
venomous bites, stings '9050'-'9052','9055'-'9056','9058','9059'
dog bites '9060'
other bites, stings '9053','9054','9061'-'9065'
hot weather '9000'

Overexertion '927 '-'9279'

Poison '850 '-'8699','980 '-'9829','950 ',
'9500'-'9529',962 '-'9629','972 '-'9729'

Struck By, Against (struck by other people or by objects) '960 ','9600','9682',
'9602'-'9609','916 '-
'9179','973 '-'9739'

Suffocate, Hang '911 '-'9139','983 '-'9839','963 ',
'953 '-'9539'

Abuse, Neglect, Rape: E-codes and Diagnosis Codes:

Spouse Abuse E-code '9673' and age over 14 or missing

Sexual Abuse if first E-code='9601' and either second
E-code is '967 ' or '9679', or else one
of the first 10 diagnoses is one of
the following: '9955 ','99550','99551',
'99553','99554','99559','99580','99581',
'99582','99583','99585';
or if one of the first 10 diagnoses is
'99553' or '99583' and the E-code is in the
range of 960-968 (assault)

Physical, Other Abuse E-codes '967 ','9670'-'9672','9674'-'9679';
also '9673' if age is less than 14

Neglect E-code '9684'

Rape by Non-Caretaker E-code '9601'

Shaken Baby if one of the first ten diagnoses is '99555'
and age is under 5 or missing and the
E-code is in the range 960-968(assault)

All Other Causes of Injury E-codes
'846 '-'8489','914 '-'9159',
'918 '-'9189','921 '-'9219',
'923 '-'9239','925 '-'9269',
'9288', '887 ','9289','9299',
'849 '-'8499', '9555','9556',
'9559','958 ','9580','9584',
'9588','9589','959 ','955 '