The Norwegian Cause of Death Registry

Christian Lycke Ellingsen

2016

The Norwegian Cause of Death Registry

• 1951 ->: Electronic records, 2.6 mill deaths

• WHO classification (ICD)

• 1996: ICD-10

• 2005: ACME (semi-automatic identification ofunderlying cause of death)

• 2002/2014: SN -> NIPH

• On the road towards e-certification

What happens in NCODR?

• Death certificates from the doctors

• Additional information

– Autopsy reports etc

• Quality control, queries

• Coding

• Data export

– Production of reports etc

– To researchers, health authorites etc

Core concepts

• A researcher must know a little about the logic in identification the cause of death

• Cause-of-death sequence and classification according to WHO (ICD-10)

• 10th revision, number 11 in the pipeline• Systematic and hierarchic, 22 chapters• More than 14.000 entities/codes

• Allows for international comparison

Underlying cause of death

• Underlying cause of death: The disease or injury that initiated the train of morbid events leading directly to death or the circumstances of the accident or violence that produced the injury.

If you ask for the cause of death, this is what you get.

Immediate cause of death

• Immediate cause of death: The disease, injury, or complication that directly results in death, i.e., the ultimate consequence of the underlying cause of death

Contributory cause of death

• Contributory cause of death: A significant condition that unfavourably influences the course of the morbid process and thus contributes to the fatal outcome, but which is not related to the disease or condition directly causing death.

• Ia: Brain haemorrhagedue to

• Ib: Brain metastasisdue to

• Ic: Lung cancer

• II: Myocardial infarction

Immediate cause of death

Underlying cause of death

Contributory cause of death

The value of a register is not better than the quality of its data (but it can of course be even less useful).

The good

• A well characterised population

– Unique identification number allows for cross-checking and register linkage

– Only 44% of births and deaths in the world formally registered

• We do have death certificates…

– 2/3 of the deaths in the world are not medically certified (WHO)

The bad

• Suboptimal quality of the death certificates

• We do not utilise all possibilities for quality improvement

• International comparison: NCoDR usually «medium-high quality»

Coverage

• 1-2 % missing death certificates

• Half of these are Norwegians dying abroad

• Total coverage good, but may be insufficient in certain subgroups

We do not live in a perfect world

• Incomplete certificates– “Detective work”, query letters

• Logical mistakes– ICD rules, ACME

• Ill-defined codes (“garbage codes”)– Where do they “belong”?

• Incorrect diagnoses– Hard to amend without checking the hospital

records

For the researcher

• What data do I need? In which detail?

• Is NCoDR the right source?

• Is the quality good enough for me?

• Are there ways to validate the data?

• Record linkage?

• Do I want to consult with the people in NCoDRabout possibilities and pitfalls?

How to order data

• Forms at FHI web site www.fhi.no

• Fully anonymous data: No problem

• Data that may identify persons:

– Application to REK or Datatilsynet

• The same regulations for persons workinginside NIPH

• Call or e-mail us!

Example 1 – record linkage

• Conscriptionexamination data onmental health functionfrom the Norwegian Defence linked to data on suicide and unintentinal injuries from NCoDR

• Unselected population

• Even those with minorimparment had elevatedrisk for dying

Example 2 – aggregated NCoDR data only

• Extreme geographical variation in thefrequency of forensic autopsies not explainedby variation in the causes of deaths

• Worryingconsequences for the investigation ofunnatural deaths?

Some useful links

• https://www.fhi.no/hn/helseregistre-og-biobanker/dodsarsaksregisteret/

• http://statistikkbank.fhi.no/dar/

• https://www.fhi.no/div/forskning-og-datatilgang/

• http://apps.who.int/classifications/icd10/browse/2016/en