1. Introduction to cause of death data - Certification, coding and data quality
Data analysis and Report writing workshop for Civil Registration and Vital Statistics data

2. Overview of session What is CoD certification and coding
Coding Resources
Underlying cause of death (UCoD)
ICD coding practices to find the UCoD
CoD Data Quality Review

3. 1. Introduction to CoD certification and coding – what is it?
For each individual death in our data set it is the process of finding and allocating a specific code for each condition on an individual death certificate and applying rules to these codes to find the Underlying Cause of Death for each person it enables all deaths to be standardised to the same output (the code), and then these can be used in tabulations and other indicators (and policy)

4. 2. Coding Resources Three main resources are required
The medical certificate cause of death
The ICD classification
Decision tables (or Iris auto-coding software)
Let’s look at each individually...

5. 2. Coding Resources - Medical Certificate of Cause of Death
So firstly the medical certificate cause of death. As I said this is the first major tool we need.
On the screen here is the standardised template that the WHO recommends for death certificates.
So the death certificate is an absolutely critical piece of information for CoD statistics. It is on the death certificate that, when a person dies, the treating doctor has to record “to the best of their ability” the causal sequence that lead to death.
Just to now outline some of the key elements of the death certificate, that at a minimum, should be provided whenever a death occurs.
Okay, starting with the largest panel there in the middle with the title cause of death. This is perhaps the most critical part of the death certificate
So as we said, when a person dies, the doctor has to record the chain of events that led to the death.
This section on the certificate contains 4 lines to be compeletd. The sequence should go in a descending “due to” manner ie. Line a is due to Line b is due to Line c is due to Line d. The condition that led directly to death (ie. The terminal condition such as heart failure, respiratory failure; end-stage conditions) should be listed on Line a. The condition that started the chain of events that led to death should be reported on the lowest used line (the underlying cause which will be discussed further later). Any intermediate conditions are reported on the lines in between.
Part 2 (the panel below) is also important, it consists of other significant conditions that contributed to the death but are not directly related to the disease or condition that caused it.
The duration between the onset of each disease and the death should be reported in the right hand column next to the appropriate lines. These are critical as well because they can inform us about whether conditions are chronic or acute, and also will impact how we apply the rules to determine what the UCOD is.
Before we move onto the next slide, can anybody think what might be missing from this certificate?? If we think back to doing tabulations etc?? Yes we are missing some critical demographic information, like date of birth, date of death, age and sex of the person, and also their location...all of these are essential to doing analysis and generating insights into the health problems of our population.... Also, some countries have a separate box on the death certificate to report on the circumstances surrounding such violent or unnatural deaths. (e.g., assaults, acts of legal intervention, suicide)

6. 2. Coding Resources - Medical Certificate of Cause of Death
Acute Renal Failure
12 days
Diabetic Nephropathy
1 yr
Diabetes (type 2)
5 yrs
Femoral neck fracture, femoral
fracture repair, Post operative haematoma

7. 2. Coding Resources - ICD 10 - International Classification of Disease
Standard diagnostic tool for classifying types of morbidity and mortality
The resource we use to find a specific codes to each condition on the death certificate
E.g. instead of “heart attack” we have “I219” for “diabetes” we have “E149”
Over 10,000 codes
Provides rules and principles for selecting codes (e.g., UCoD)

8. 2. Coding Resources - Decision Tables

9. 3. Underlying Cause of Death (UCoD)
The WHO defines the UCOD as
“the disease or injury which initiated the train of morbid events leading directly to death...”
External causes – head injury vs car accident
Is based on the concept of where in the causal sequence you would intervene to prevent that happening to someone else
The UCoD is used to tabulate our CoD statistics
There are rules for coders around how to select the underlying cause of death

10. 4. ICD 10 Coding Rules used to find the UCoD
Information here comes from ICD 10, Volume 2, Instruction Manual, and is available online for free...
en_2016.pdf

11. 4. ICD 10 Coding Rules used to find the UCoD
Basic concept 1: Finding the causal sequence & avoiding end stage conditions
The term ‘sequence’ refers to a chain or series of medical events in which each step is a complication of, or is caused by, the previous step
To find the UCoD, the coder is looking for a plausible sequence starting on the top line and working backwards to the last condition mentioned in part 1 of the death certificate
At the same time, we want to avoid selecting an end-stage condition when we have other conditions on the certificate which lead to that end stage condition...

12. Finding the causal sequence & avoiding end stage conditions – eg 2
Renal Failure (N19)
12 days
Ischemic Heart Disease (I259)
5 yrs

13. 4. ICD 10 Coding Rules used to find the UCoD
Basic concept 2: Dealing with more than one sequence
Basic concept 3: Addressing obvious cause
Basic concept 4: Ill-defined conditions and conditions unlikely to cause death

14. 1d. Data quality review – CoD data - Ill-defined codes
Ill-defined codes are important to pay closer attention to as they can influence our overall output...
How prevalent are ill-defined codes as the UCoD in your data set?
Is it possible to go back to the source data and confirm that no better cause of death is available?
Page 213, ICD-10 Volume 2 Instruction Manual – available online

15. Ill-defined conditions and conditions unlikely to cause death eg 1
Old age (R54)
Ischemic Heart Disease (I259)

16. 4. ICD 10 Coding Rules - External Causes
When reporting external causes of death the certifier must also describe the circumstances of the incident or accident that led to death.
 Coding is based on HOW the injury / event occurred as this is what you need to know for prevention ie fractured skull DUE TO Motor vehicle accident
Intent is critical from a coding perspective

17. 5. Data quality review – CoD data
Before we tabulate data, we want to ensure the quality is as good as it can be...
We’ve used the ICD to code deaths, but the accuracy and quality of causes of death data can be affected by issues relating to:
1. Certification issues
2. Demographic inconsistencies
3. Coding errors (esp. Ill-defined codes)
We need to run this ‘3 point-filter’ over our data to check its accuracy
Let’s look at each one in turn...

18. 5. Data quality review - CoD - certification issues
Events and issues which influence the certifier which can impact coding
Info quality and availability
Training and knowledge
Attitudes towards certification
Ease of diagnosis of certain diseases
Diseases associated with stigma
These can’t necessarily be fixed by the coder but need to be considered, and if possible, understood and discussed in reports...

19. 5. Data quality review – CoD data - demographic inconsistencies
Need to do data quality checks at the individual record level. Consider…
Sex issues, such as: - Males who died giving birth - Females who died of prostate cancer - Males who died of cervical or breast cancer
Age issues, such as: - Adults dying from congenital causes Children dying from type 2 diabetes - Children or young adults dying from dementia
Inconsistent records may need to be changed based on other information found on the certificate or record...

20. 5. Data quality review - CoD data - coding issues
Remember our coding rules and basic concepts? We need to make sure that these have been followed...
Causal sequence & end stage condition? Check.
First mentioned sequence? Check.
Obvious cause? Check.
Ill-defined code and those unlikely to cause death not UCoD if other things on cert?
Decision tables used to aid coding (if possible)? Check

21. 5. Data quality review - Final checklist for CoD records
Remember - we want to check our cause of death data at the individual record level...
Have we considered possible certification issues for the record?
Is there a valid ICD 10 code recorded for each condition?
Is there a valid UCoD assigned to each record?
Have we checked for demographic inconsistencies?
A final sense check – does the record look and feel accurate given our current level of knowledge and experience?
Others??? May depend upon your country’s situation...