Burden of Disease Research Unit
WHO-FIC Collaborating Centre (Under designation)
Cause of death statistics
from vital registration
Debbie Bradshaw
Outline of presentation
• Illustrate the public health value of cause of
death statistics – City of Cape Town
• Process of collecting cause of death statistics
•
•
•
•
ascertaining the cause of death
underlying cause of death
ICD coding
cause of death statistics
• Quality of cause of death certification
Cause of death profile in Cape Town, 2004
Source: Western Cape BOD project using City of Cape Town mortality data
Age specific HIV death rates, Cape Town 2001 - 2006
HIV Females
HIV Males
200
200
150
150
2001
100
100
2004
2006
50
50
0
0
0-4
5-14
15-24 25-34
35-44
45-54 55-64
65-74
75+
0-4
5-14
15-24
25-34
35-44
45-54
55-64
Source: Western Cape BOD project using City of Cape Town mortality data
65-74
75+
Age-standardised death rates (per 100 000 population)
Cape Town, 2001 – 2006
120
100
80
60
40
20
0
2001
2002
2003
2004
2005
2006
Ischaemic heart disease
Stroke
Diabetes mellitus
Hypertensive heart disease
Source: Western Cape BOD project using City of Cape Town mortality data
Age-standardised death rates (per 100 000 population)
by broad cause for sub-districts of Cape Town, 2006
2000
1800
1600
Deaths per 100 000
1400
1200
1000
800
600
400
200
HIV/AIDS
Other Communicable/mat/peri/nutrition
Source: Groenewald et al, 2008
Non-communicable diseases
Cape Town
Southern
Northern
Western
Tygerberg
Klipfontein
Mitchels Plain
Eastern
Khayelitsha
0
Injuries
Leading causes of premature mortality, Cape Town 2006
2006
HIV/AIDS
16.1
Homicide
14.4
Tuberculosis
8.4
Road traffic
5.3
Lower Respiratory infections
4.1
Ischaemic heart disease
3.7
Stroke
3.4
Diabetes Mellitus
3.4
Low birth weight and RDS
Percentage of total
Years of Life Lost
(YLLs)
2.9
Diarrhoeal Diseases
2.5
0
5
10
Percentage
Source: Western Cape BOD project using City of Cape Town mortality data
15
20
Public health importance of mortality data
• Monitor the health of the population
– Leading causes of death
– Mortality rates (geographic variations)
– Trends over time
• Inform decisions about health policy and strategy
– Prevent premature deaths
– Service provision
– Health budgets
• Evaluate health service outcomes
Main stages in production of cause of
death statistics
Attending doctor:
• Establish diagnosis
• Complete death certificate (International form – WHO)
Coding by Statistical Office:
• Code causes of death (ICD code for each cause listed)
• Classify cause of death (select a single underlying cause of death for stats
according to ICD selection rules)
• Check validity, query
Analysis by Statistical Office:
• Tabulate and disseminate data
Source: Adapted from Johansson LA, 2008
G MEDICAL CERTIFICATE OF CAUSE OF DEATH
Part 1
Enter the diseases, injuries or complications that caused the death. Do not enter the
mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. List only one cause
on each line.
IMMEDIATE CAUSE
(Final disease or condition
resulting in death
Sequentially list condition,
if any, leading to
immediate cause. Enter
UNDERLYING CAUSE last
(a) …………………………...………
Due to, (or as a consequence of)
(b) ………………………….……….
Due to, (or as a consequence of)
(c) ………………………………….
Due to, (or as a consequence of)
Immediate cause
on top line
……………….
Any causal sequence
………………..
with underlying
cause
at the bottom
……………….
(d) ………………………………..
Part 2 Other significant conditions
contributing to death but not resulting
in underlying cause given in Part 1
.………………………………
Approximate
interval between
onset and death
(Days/Months/Years)
……………….
Contributing cause
but not in causal sequence
……………….
in Part 2
__________________________________________________________________________________
According to ICD-10:
• The Immediate Cause is the final disease, injury or complication directly
causing the death. It should be noted that the mechanism of death or terminal
event (for example, cardiac arrest or respiratory arrest) is not considered to be a
cause of death. The mechanism of death should not be reported as the
immediate cause of death as it is a statement not specifically related to the
disease process, and it merely attests to the fact of death.
• The Underlying Cause of Death is the disease or injury that started the
sequence of events leading directly to death or the circumstances of the
accident or violence that produced the fatal injury. In the case of a violent
death, the form of external violence or accident is antecedent to the injury
entered, although the two events may be almost simultaneous.
• Part II is for reporting all other significant diseases, conditions, or injuries that
contributed to death but which did not result in the underlying cause of death
given in Part I.
A 75-year-old female had a 15-year history of non-insulin-dependent diabetes
mellitus, a 13-year history of mild hypertension treated with thiazide
diuretics, and an uncomplicated myocardial infarction 6 years prior to the
present illness. She was found disoriented at her home and brought to
hospital. On admission she was noted to be unresponsive, without focal
neurologic signs, and severely dehydrated with a blood pressure of 90/60.
Initial laboratory tests disclosed severe hyperglycemia, hyperosmolarity,
azotemia, and mild ketosis without acidosis. A diagnosis of hyperosmolar
nonketotic coma was made. The patient was treated with fluids, electrolytes,
insulin and broad-spread antibiotics. Within 72 hours, the patient’s
hypersomolar, hyperglycemic state was resolved. However, she remained
anuric with progressive azotemia. The patient died on the 8th hospital day in
severe renal failure.
G MEDICAL CERTIFICATE OF CAUSE OF DEATH
Part 1
Enter the diseases, injuries or complications that caused the death. Do not enter the
mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. List only one cause
on each line.
IMMEDIATE CAUSE
(Final disease or condition
resulting in death
Sequentially list condition,
if any, leading to
immediate cause. Enter
UNDERLYING CAUSE last
Acute renal failure
(a) …………………………...………
Due to, (or as a consequence of)
Hyperosmolar nonketotic coma
5 Days
……………….
8 Days
(b) ………………………….……….
Due to, (or as a consequence of)
………………..
(c) ………………………………….
dependent
Due to, (or as a consequence of)
15 Years
……………….
Diabetes mellitus, non-insulin
(d) ………………………………..
Part 2 Other significant conditions
contributing to death but not resulting
in underlying cause given in Part 1
Approximate
interval between
onset and death
(Days/Months/Years)
Hypertension,
Previous
myocardial infarction
.………………………………
__________________________________________________________________________________
……………….
……………….
Female aged 77 years, stumbled and fell over while cleaning the house and
sustained a fracture of the neck of the left femur. She had an operation for
insertion of a pin the following day. Four weeks later her condition
deteriorated, she developed hypostatic pneumonia and died two days later.
G MEDICAL CERTIFICATE OF CAUSE OF DEATH
Part 1
Enter the diseases, injuries or complications that caused the death. Do not enter the
mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. List only one cause
on each line.
IMMEDIATE CAUSE
(Final disease or condition
resulting in death
Sequentially list condition,
if any, leading to
immediate cause. Enter
UNDERLYING CAUSE last
Terminal Hypostatic Pneumonia
(a) …………………………...………
Due to, (or as a consequence of)
Fractured Left Neck of Femur
(b) ………………………….……….
Due to, (or as a consequence of)
2 Days
……………….
4 weeks
………………..
Accidental fall while cleaning at home 4 weeks
(c) ………………………………….
……………….
Due to, (or as a consequence of)
(d) ………………………………..
Part 2 Other significant conditions
contributing to death but not resulting
in underlying cause given in Part 1
Approximate
interval between
onset and death
(Days/Months/Years)
.………………………………
__________________________________________________________________________________
……………….
……………….
G MEDICAL CERTIFICATE OF CAUSE OF DEATH
Part 1
Enter the diseases, injuries or complications that caused the death. Do not enter the
mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. List only one cause
on each line.
IMMEDIATE CAUSE
(Final disease or condition
resulting in death
Sequentially list condition,
if any, leading to
immediate cause. Enter
UNDERLYING CAUSE last
Cancer
(a) …………………………...………
Due to, (or as a consequence of)
……………….
Diabetes
(b) ………………………….……….
Due to, (or as a consequence of)
………………..
(c) ………………………………….
Due to, (or as a consequence of)
……………….
(d) ………………………………..
Part 2 Other significant conditions
contributing to death but not resulting
in underlying cause given in Part 1
Approximate
interval between
onset and death
(Days/Months/Years)
.………………………………
__________________________________________________________________________________
……………….
……………….
G
MEDICAL CERTIFICATE OF CAUSE OF DEATH
Part 1
Enter the diseases, injuries or complications that caused the death. Do not enter the
mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. List only one cause
on each line.
Approximate
interval between
onset and death
(Days/Months/Years)
Stroke
IMMEDIATE CAUSE
(Final disease or condition
resulting in death
(a) …………………………...………
Due to, (or as a consequence of)
……………….
Sequentially list condition,
if any, leading to
immediate cause. Enter
UNDERLYING CAUSE last
Pneumonia
(b) ………………………….……….
Due to, (or as a consequence of)
………………..
(c) ………………………………….
Due to, (or as a consequence of)
……………….
(d) ………………………………..
Part 2 Other significant conditions
contributing to death but not resulting
in underlying cause given in Part 1
.………………………………
__________________________________________________________________________________
……………….
……………….
FO
O
IC
G MEDICAL CERTIFICATE OF CAUSE OF DEATH
Part 1
Enter the diseases, injuries or complications that caused the death. Do not enter the
mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. List only one cause
on each line.
IMMEDIATE CAUSE
(Final disease or condition
resulting in death
Sequentially list condition,
if any, leading to
immediate cause. Enter
UNDERLYING CAUSE last
Cardiac arrest
(a) …………………………...………
Due to, (or as a consequence of)
……………….
(b) ………………………….……….
Due to, (or as a consequence of)
………………..
(c) ………………………………….
Due to, (or as a consequence of)
……………….
(d) ………………………………..
Part 2 Other significant conditions
contributing to death but not resulting
in underlying cause given in Part 1
Approximate
interval between
onset and death
(Days/Months/Years)
.………………………………
__________________________________________________________________________________
……………….
……………….
Terminology
Terminology that should be avoided
• Ill-defined / non-specific conditions
– Old age
– Headache
– “Natural causes”
• Mechanisms of death
–
–
–
–
–
Heart failure
Kidney failure
Dehydration
Hypoxia
Sepsis
Things that should not be on the certificate
• Abbreviations
–
–
–
–
DM II
MI
MS
HONK
• Stories
– The patient presented three days ago with severe abdominal
pain, but the family says it’s been going on for a long time. At
surgery extensive peritoneal sepsis of unknown cause was
found.
Things that should not be on the death certificate
In the case of Human Immunodeficiency Virus
– Check hospital notes for HIV-tests or treatment
– Underlying COD: Human immunodeficiency virus
– Intermediate COD: Acquired Immunodeficiency syndrome
– Immediate COD: Tuberculosis / Cryptococcal Meningitis, etc.
Processing information from the medical certificate
• Code each cause according to the International Statistical
Classification of Diseases and Related Health Problems
(ICD-10)
• Apply ICD-10 rules to establish the Underlying cause of
death
• Check the validity of the information – and query or correct
• Check consistency of data eg prostate cancer for female
http://www.who.int/classifications/icd/en/
ICD – 10
A00 Cholera
A00.0 Cholera due to Vibrio cholerae 01, biovar cholerae
A00.1 Cholera due to Vibrio cholerae 01, biovar eltor
A00.9 Cholera, unspecified
Z99 Dependence on enabling machines and devices, not elsewhere
classified
Z99.0 Dependence on aspirator
Z99.1 Dependence on respirator
Z99.2 Dependence on renal dialysis
Z99.3 Dependence on wheelchair
Z99.8 Dependence on other enabling machines and devices
Z99.9 Dependence on unspecified enabling machine and device
ICD – 10 Chapters
A00 – B99
C00 – D48
D50 – D89
E00 – E90
F00 – F99
G00 – G99
H00 – H59
H60 – H95
I00 – I99
J00 – J99
K00 – K93
L00 – L99
M00 – M99
N00 – N99
O00 – O99
P00 – P99
Q00 – Q99
R00 – R99
Certain infectious and parasitic diseases
Neoplasms
Diseases of the blood and immune mechanism
Endocrine, nutritional and metabolic disorders
Mental and behavioural disorders
Diseases of the nervous system
Diseases of the eye and adnexa
Diseases of the ear and mastoid process
Diseases of the circulatory
Diseases of the respiratory diseases
Diseases of the digestive system
Diseases of the skin and subcutaneous tissue
Diseases of the musculoskeletal system
Diseases of the genitourinary system
Pregnancy, children and puerperium
Perinatal conditions
Congenital malformations
Symptoms and signs not elsewhere defined
V01 – Y98
External causes of morbidity and mortality
S00 – T99
Z00 – Z99
Nature of injury
Reasons for encounter with health service
Problems with cause of death statistics
Errors can occur at all stages of production:
– Diagnosis
– Death certification
• Errors (mechanism of death/no UC, competing causes, incorrect sequence)
• Insufficient information
– Coding
– Classification (incorrect or inconsistent application of ICD selection rules)
– Analysis
HIV - males
TB - m ale
1996
1996
2000/01 sample
2000/01 sample
700
1000
600
500
800
400
600
300
400
200
200
100
1996
TB - fem ale
300
85+
75-79
1996
HIV - females
2000/01 sample
65-69
55-59
45-49
35-39
25-29
15-19
5-9
85+
75-79
65-69
55-59
45-49
35-39
25-29
15-19
5-9
0
0
0
0
2000/01 sample
1000
250
800
200
600
150
Source: Groenewald et al, 2005
85+
75-79
65-69
55-59
45-49
35-39
25-29
15-19
5-9
85+
75-79
65-69
55-59
45-49
35-39
25-29
0
15-19
0
5-9
200
0
50
0
400
100
Death certification quality in Cape Winelands and Overberg:
Percentage ill-defined causes of death by sub-district
30
25
Percentage
20
15
10
5
0
Breede River
Breede Valey
Winelands
Drakenstein
Stellenbosch
Witzenberg
Cape Agulhas
Overstrand
Swellen
Theewaters
10
2004
26
10
7
14
12
15
2005
27
10
7
12
8
14
7
2006
20
13
17
13
10
10
10
9
9
Review of certificates in Vangaurd: Major errors
• Incorrect sequencing in Part 1
28.7%
• Competing causes of death in Part 1
15.3%
• Lack of a proper underlying cause of death
14.8%
• A mechanism of death, without an underlying cause of
death
13.5%
• One or more major errors in DNF
Source: Burger et al., 2007
43.4%
Review of certificates in Vangaurd : Minor errors
• Absence of a time estimate between onset of disease and
death
• Use of abbreviations
• Recording of inappropriate information
• Illegible handwriting
• One or more minor errors in DNF
Source: Burger et al., 2007
81.5%
23.7%
13.0%
2.5%
86.1%
In total 91,7% of cases had at least one
error!!
Serious major errors and associated factors,
Academic Hospital in Cape Town
Characteristic
OR
95% CI
Sex
p-value
Characteristic
0.8017
Department
OR
95% CI
0.5375
Male
1.0
-
Casualty
1.0
-
Female
1.0
0.8-1.4
Medical general
1.8
1.2-2.8
Medical specialised
2.0
1.2-3,2
Age
0.1260
Neonates
1.0
-
Surgical
1.4
0.9-2.2
1 mth – 4 yrs
1.4
0.1-21.4
Neonates
3.3
0.2-62.8
5-14
2.5
0.1-122.3
15-24
7.3
0.3-203.4
Neoplasms
1.0
-
25-34
3.2
0.1-78.7
Circulatory
3.4
2.1-5.5
35-44
4.5
0.2-108.7
Infectious/parasitic
4.3
2.3-8.0
45-54
5.3
0.2-124.9
Respiratory
4.7
2.5-9.0
55-64
3.8
0.2-90.4
Endocrine/nutrtional/metab
17.2
8.7-34.0
65-74
6.2
0.3-147.3
Digestive
6.3
3.1-12.9
75+
7.0
0.3-168.0
Perinatal conditions
3.4
0.8-15.0
Genitourinary
17.3
7.8-38.2
Other
5.8
2.9-11.5
Source: Nojilana et al., 2008
p-value
Cause of death
<0.001
HIV test
information from
medical record
for sub-sample
242
Potentially HIV/AIDS related
causes*
71
not tested
for HIV
38
33
Tested for
HIV
HIV +ve
HIV -ve
6
32
15
recorded on
death certificate
6
not reported on
death certificate
0
recorded on
death certificate
17
not recorded on
death certificate
Brief intervention for interns
Proportion with adequate score
N
Pre-test
%
Post-test
%
McNemar’s
Overall group
24
13
88
<0.0001
Intervention group
13
15
84
0.0027
Control group
11
9
91
0.0027
Source: Pieterse et al., 2008
p-value
http://who.int/bookorders
www.healthmetricsnetwork.org
healthmetrics@who.int
Domains of Measurement
Determinants of Health
Health status
Socio-economic and demographic factors
Environmental and behavioural risk factors
Service seeking behaviours
Mortality
Morbidity/
Disability
Health System
Inputs
Outputs
Policy
Information
Financing
Service
Human resources (availability
Organisation
and quality)
Source: Health Metrics Network
Outcomes
Coverage
Utilisation
Well-being
http://www.who.int/classifications/icd/en/
Acknowledgement
BOD Unit and collaborators
Dr Pam Groenewald
Dr Lene Burger
Ms Desiree Pieterse
Ms Beatrice Nojilana
WHO-FIC Collaborating Centre
Ms Lyn Hanmer
Dr Pam Groenewald
Mr Malute Tshivase
Ms Margie Schneider
Prof Jenny Jelsma
Mr David Bourne
Me Sedick Isaacs
Local, provincial and national government
City of Cape Town
Western Cape Department of Health
Department of Home Affairs
Statistics South Africa