Transcript Assessing the Concordance of Coded Morbidity and Mortality Data for In-Hospital Trauma-Related Deaths Presenter: Research Team: Affiliations: Bridget Allison Kirsten McKenzie, Sue Walker, Leanne Aitken, Andrea Besenyei, Deirdre.

Assessing the Concordance of Coded
Morbidity and Mortality Data for
In-Hospital Trauma-Related Deaths
Presenter:
Research Team:
Affiliations:
Bridget Allison
Kirsten McKenzie, Sue Walker, Leanne Aitken,
Andrea Besenyei, Deirdre McDonagh
National Centre for Classification in Health, QUT
Institute of Health and Biomedical Innovation, QUT
Queensland Trauma Registry, UQ
National Centre for Classification
in Health
• Mission:
The National Centre for Classification in Health
(NCCH) is the Australian centre of excellence in
health classification theory and an expert centre
in coding systems. The NCCH is dedicated to
supporting our clients in their use of health
classifications and related products.
Background
• In-hospital mortality rate key indicator of
trauma system effectiveness
• Few researchers have investigated the
concordance of causes of death and causes of
hospital admission
• Are the same causes of trauma listed on death
certificate as documented in hospital records?
Factors affecting concordance of
morbidity and mortality data
• Different coding guidelines and selection
rules
• Differences in classification versions used
• Coding errors
• Documentation differences
• Autopsy and certification processes
Different coding guidelines, selection rules, and
classification versions used
• Principal Diagnosis (ICD-10-AM)
– The principal diagnosis is considered to be chiefly responsible for
occasioning the patient's episode of care in hospital
• Underlying Cause of Death (ICD-10)
– The underlying cause of death is defined as (a) the disease or injury
which initiated the train of morbid events leading directly to death, or
(b) the circumstances of the accident or violence which produced the
fatal injury
– Cause of injury is the UCOD for deaths due to trauma
• Multiple Causes of Death
– All other conditions, including the injuries resulting from the
external cause, are coded as multiple causes of death
• Part I and Part II of Death Certificate
Coding errors
• Incomplete or inaccurate coding affects
data quality
• Previous research has identified errors in
injury coding and external cause coding
affecting up to 28% of medical records
Documentation differences
• Morbidity coders have complete hospital record
to code from while mortality coders largely
confined to death certificate
• Previous research found that concordance of
hospital records and death certificates varies by:
–
–
–
–
–
Principal diagnosis
Type and number of co-morbidities of the patient
Time from admission to death
Acuity of the condition
Details available regarding the diagnoses
Autopsy and certification processes
• Certifier may be unaware of prior injury
• Certifier may not consider the injury to be a
contributory factor towards the death
• Certifier may not document the injury and/or
external cause on the death certificate
• Autopsy results may not be available for coding
of hospital records and/or death certificate
Research Questions
• What was the in-hospital mortality rate for
patients admitted to hospital for trauma?
• Was trauma recorded on the death
certificate of patients who died in hospital?
• If trauma was recorded, was there
concordance in the coded data between
the morbidity and mortality collections for
trauma patients who died in hospital?
Research Methodology
• Participants = 1672 patients admitted to
hospital for >24hrs with PDx of injury
• Procedure:
– Data matched to NDI using probabilistic
matching based on demographic variables (name,
sex, DoB etc)
– NDI reported specificity 98.5% and sensitivity
89.2% (Kelman, ANZJPH, 2000, 24 (2) pp. 201-203)
– Matched cases formed sample for this research
Results
• Of 1672 trauma admissions, 3.6% died in
hospital (n=60)
• Medical vs Traumatic COD
– 89% had trauma coded in NDI though 18% of these
had medical condition as UCOD
– 11% did not have trauma coded in NDI
• Age by medical vs traumatic COD
– All but one person <65 had trauma as UCOD
– Only 50% of >65 year olds had trauma as UCOD
Most Common Causes of Injury by
Medical vs Traumatic UCOD
100%
Medical UCOD
80%
60%
Trauma MCOD
40%
20%
0%
Trauma UCOD
MVA
(n=15)
Falls
(n=21)
Suicide
(n=7)
Results
• Concordance of cause of injury between
morbidity and mortality data:
–
–
–
–
36% same cause of injury
14% more defined cause in NDI
22% less defined cause in NDI
28% no match
• Age by concordance of cause of injury data
– 67% <65 had matched or more detailed NDI data
– Only 27% >65 year olds had matched NDI data
Most Common Causes of Injury by
Concordance with NDI
100%
No Match
80%
NDI Less Specific
60%
40%
NDI More Specific
20%
Match
0%
MVA
(n=14)
Falls
(n=17)
Suicide
(n=6)
Discussion
• Despite being admitted and treated for trauma related
injuries
– 18% of cases did not have a trauma-related UCOD and
– 11% of cases did not have a trauma-related code in the
National Death Index
• People over 65 years old less likely to have trauma
documented on death certificate, though trauma
arguably increases risk of dying from co-morbidities
Discussion
• Where trauma was documented on death
certificate, causes of injury not concordant
between morbidity and mortality data with 50%
less defined or no match in NDI
• Use of unspecified codes on NDI (e.g. Exposure to
unspecified factor) compared with more detailed coded
hospital morbidity data (e.g. fall from bed) -> Unable to
determine that injury caused by fall if using
mortality data alone
Recommendations
• Use linked hospital morbidity data in conjunction
with national mortality data to afford greater detail
for trauma outcome research
• Consider aims of your research and determine
most appropriate source of coded data
• Understand the underlying constraints inherent in
the production of national morbidity and mortality
datasets and how this affects data quality
Future Developments
• Study conducted using data from a single
hospital and a single trauma registry and
using a small sample
• Expanding to include all QTR sites for 2003,
~ 12,000 trauma admissions
Further information
Bridget Allison
Health Information Manager
National Centre for Classification in Health
[email protected]
Ph. 07 3864 3911