This is my first blog post for my project on the ¨Medical Analysis of the Chilean National Forensic Database from an Emergency Medicine Perspective.¨ Actually, this is my first blog post ever, so hopefully it´s good! First, I´m going to give a brief introduction on the project. Then I will describe the 10th revision of the International Classification of Disease (ICD-10) and its importance in my project.
The Chilean doctors involved in this project work at the Pontificial University Catholic University of Chile.
My research project is a descriptive study on mortality rates due to injuries in Greater Santiago using the Chilean National Forensic Database from 1997 till 2010. Over the past couple months I´ve been working with Emergency Medicine physicians from USC, Dr. William Mallon, and the Pontifical Catholic University of Chile (PUC), Dr. Pablo Aguilera, Dr. Oscar Navea, and Dr. Marcela Garrido, to develop the project. The database includes the external cause (motor vehicle, gunshot, poisoning, etc.); the victim´s age, gender, and alcohol level; the nature of the injury (fracture of skull, third degree burn of hand, traumatic pneumothorax, etc.), the commune of the victim´s residence and the commune where the incident occurred (commune is an administrative division–it is comparable to a county); the origin of the victim´s body (hospital, street, jail, etc.); and the date of the incident. Essentially, we are looking to create a statistical description of deaths in Santiago of who, when, where, and why. It may not seem like we are looking at a lot, but we are looking at nearly 25000 victims in the database.
Marcela (left) and Pablo (right) in the office after our first meeting in Chile.
The sections on external cause and nature of injury (in our case death–all the entries in the forensic database are mortalities) are coded using the 10th revision of the International Classification of Disease (ICD-10). More specifically, the external cause of injury is coded using Chapter 20 of ICD-10 and the nature of injury is coded using Chapter 19. The dataset we are using has 850 unique codes for external cause and 500 codes for the nature of injury (however, we are not interested in the nature of injury for this study). These codes are used to facilitate the comparison of disease statistics between different countries. As I already mentioned, I´m only interested in one chapter of ICD-10: chapter 20. The codes used in this chapter are broken down into several groups including: transport accidents (car accidents, airplane crashes, etc.), other types of accidents (Falls, poisoning, etc.), intentional self-harm, assault, legal intervention and operations of war, complications of medical and surgical care, and a few others. This database only includes codes from the first 4 groups. These groups are further broken down based on the type of transport accident, the type of non-transport accident, and the method of self-harm or assault.
To give you a better idea of what information is included in the ICD-10 codes, and what I am doing for this research project, I´m going to take a few sample ICD-10 codes and decode them. Lets start with V03.12. The main code is ¨V03¨ while ¨12¨ is a subdivision. The ¨V¨ tells us that this was a transport accident. The other letters used in Chapter 20 include W, X, and Y. Our dataset only includes V´s and X´s (X´s can be used for non-transport accidents, intentional-self harm, and assault). For transport accidents, the first number also helps group the accidents: 0 refers to pedestrian victims, 1 refers to pedal cyclists, 2 refers to motorcyclists, etc. So, what does ¨V03¨ mean? It means that the victim was a pedestrian injured in a collision with a car, pick-up truck, or van.
Now you may remember what that the code was V03.12, so what about the .12? As I said before, the numbers following the decimal place are subdivisions (NOTE: from what I understand different countries and different sources can present the subdivision characters differently. They can present them following a decimal place, or they can present them separately). For transport accidents, the meaning of the first subdivision number varies depending on the first three characters (in this case V03). In our example, V03, the ¨1¨ means that it was a traffic accident (a ¨0¨ refers to non-traffic accidents while a ¨9¨ means that it was not specified if the accident was traffic or non-traffic). Let´s say that our code was V44.12. The first three characters, V44, refers to a car occupant injured in a collision with a heavy vehicle or bus. In this case, the fourth character, ¨1¨, indicates that the occupant was a passenger injured in a non-traffic accident. For all types of injures other than traffic accidents, the fourth character refers to the place of occurrence, which I´ll address later in our next example.
Finally, we have the 5th character. Remember our code is V03.12. Fortunately, the fifth character is the same for all types of injuries. It is the activity code and it tells us what the victim was doing when they were injured. A ¨2¨ means that the victim was injured while working for income (other codes include ¨0¨ for sports, ¨1¨ for leisure, etc.). So, in conclusion, V03.12 means that that victim was a pedestrian injured in a traffic accident involving a collision with a car, pick-up truck, or van while working for income.
New Year´s Day at parque los dominicos.
Let´s try one more code (because I know you are enjoying this so much). This time the code is X45.51. The X45 indicates that the victim suffered accidental poisoning by exposure to alcohol (it includes ethanol and other types). Meanwhile, the fourth character ¨5¨ means that the poisoning occurred in a trade or service area, such as an airport, restaurant, or supermarket. Finally, the fifth character ¨1¨ tells us that the accidental poisoning occurred during leisure activity.
Now if you are still awake, and if you enjoyed learning about disease coding, you can learn more about it at the WHO website, which includes an online version of ICD-10 and an online training program. http://www.who.int/classifications/icd/en/