Semantic inconsistency of classification systems: Let’s try GEM

In our Bachelor course on classification systems, I introduce the idea behind classification systems and also present the topic of “semantic inconsistency”. I know from the exams in this module that this is an issue that the student seldom fully understand, even when I try to explain this in class quite well. So here is my idea of using GEM:

Within the module, students first get an introduction into the idea of classification system. Classification systems allow to clearly assigning an item to a class (e.g. a very good presentation is assigned the mark “A+”). This assignment must be fully clear, to avoid misclassifications. Classification system that allow this are called “semantic consistent”, the others “semantic inconsistent”.

To further work on this concept, I will present a short instruction into ICD10 – the 10^th edition of the International Classification of Diseases. I will introduce the ICD10 browser at http://apps.who.int/classifications/icd10/browse/2016/en.

Then let’s start with GEM:

Step 1: Generate

Compile information:

• Students are asked to work a bit with the ICD10 tool, to get familiar on how it works.
• Students then get a list of 10 – 20 simple diagnosis that they are asked to code. They are asked to compare their findings with their neighbor. Examples:
  • Angina pectoris -> Code: I20.0
  • Acute sinusitis -> Code: J01
  • Alcoholic liver disease -> Code: K70
  • Atopic dermatitis -> Code: L20

Generate relationships:

• Based on these examples, students are asked to explain how ICD10 is organized: What is the organizing principle?
  • Students will find out that ICD is (mostly) organized according to organ system (nervous system, eyes, circulatory system, respiratory system, digestive system etc.)
  • Students will be asked to find some proof of this assumption by showing some codes related to organ systems.

Step 2: Evaluate

• Students are asked to code a list of further diagnosis such as:
  1. liver cancer
  2. viral hepatitis
  3. respiratory tuberculosis
• Students are asked what is happening here, what is wrong?
  • They will find out that these diagnosis are not only coded according to organ system, but on different axes
    • liver cancer -> Code: C22.9 (Axe: Neoplasm)
    • respiratory tuberculosis -> Code: A15 (Axe: Infectious diseases)
  • Students are asked to find more such examples of codes not organized according to organ system

Step 3: Modify

• Students are asked to explain why this can happen
  • They will find out that ICD10 axes are related to different perspective of coding (“organ system” versus “type of disease”)
• Students as asked to look again at the ICD: So what is the organizing principle?
  • It is a mix of organ system and type of disease
• Students are asked what this means for the coding person
  • They will find out that indeed such a diagnosis could be coded in two area (viral hepatitis may be coded either as liver disease or as infectious disease)
• Students are asked to discuss with their neighbor how this problem be solved
  • They may come up with the idea that coding rules are needed
• Students are asked to find out how ICD solves the problem
  • They will find out that indeed ICD includes rules, named “exclusion/inclusion” that clear point to one axe
  • For example: Viral hepatitis is not coded as liver disease, but as infectious disease

Okay, this is quite a complex example, but we are at the bachelor level here, so I guess this could work out. In any case, it is worth a try – I have this module in March, so I will try this exercise.

Do you think the approach could work?

Elske