Burden of Disease Research Unit

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Burden of Disease Research Unit
WHO-FIC Collaborating Centre (Under designation)
Cause of death statistics from vital
registration Debbie Bradshaw
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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

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Cause of death profile in Cape Town, 2004
Source Western Cape BOD project using City of
Cape Town mortality data
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Age specific HIV death rates, Cape Town 2001 -
2006
Source Western Cape BOD project using City of
Cape Town mortality data
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Age-standardised death rates (per 100 000
population) Cape Town, 2001 2006
Source Western Cape BOD project using City of
Cape Town mortality data
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Age-standardised death rates (per 100 000
population) by broad cause for sub-districts of
Cape Town, 2006
Source Groenewald et al, 2008
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Leading causes of premature mortality, Cape Town
2006
Percentage of total Years of Life Lost (YLLs)
Source Western Cape BOD project using City of
Cape Town mortality data
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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

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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
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Immediate cause on top line
Any causal sequence with underlying cause at
the bottom
Contributing cause but not in causal sequence in
Part 2
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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.

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• 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
  patients hypersomolar, hyperglycemic state was
  resolved. However, she remained anuric with
  progressive azotemia. The patient died on the 8th
  hospital day in severe renal failure.

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Acute renal failure
5 Days
Hyperosmolar nonketotic coma
8 Days
Diabetes mellitus, non-insulin dependent
15 Years
Hypertension, Previous myocardial infarction
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• 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.

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Terminal Hypostatic Pneumonia
2 Days
Fractured Left Neck of Femur
4 weeks
Accidental fall while cleaning at home
4 weeks
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Cancer
Diabetes
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Stroke
Pneumonia
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Cardiac arrest
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Terminology
Nothing!
Cardio-Respiratory Arrest
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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

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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 its been
  going on for a long time. At surgery extensive
  peritoneal sepsis of unknown cause was found.

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Things that should not be on the death certificate
Nothing!
zxcv uiodsa bhcox
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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.

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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

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http//www.who.int/classifications/icd/en/
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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
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ICD 10 Chapters
A00 B99 Certain infectious and parasitic
diseases C00 D48 Neoplasms D50 D89 Diseases
of the blood and immune mechanism E00 E90
Endocrine, nutritional and metabolic
disorders F00 F99 Mental and behavioural
disorders G00 G99 Diseases of the nervous
system H00 H59 Diseases of the eye and
adnexa H60 H95 Diseases of the ear and mastoid
process I00 I99 Diseases of the circulatory
J00 J99 Diseases of the respiratory
diseases K00 K93 Diseases of the digestive
system L00 L99 Diseases of the skin and
subcutaneous tissue M00 M99 Diseases of the
musculoskeletal system N00 N99 Diseases of the
genitourinary system O00 O99 Pregnancy,
children and puerperium P00 P99 Perinatal
conditions Q00 Q99 Congenital malformations R00
R99 Symptoms and signs not elsewhere
defined S00 T99 Nature of injury V01
Y98 External causes of morbidity and
mortality Z00 Z99 Reasons for encounter with
health service
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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

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Source Groenewald et al, 2005
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Death certification quality in Cape Winelands and
OverbergPercentage ill-defined causes of death
by sub-district
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Review of certificates in Vangaurd Major errors
28.7 15.3 14.8 13.5 43.4

• Incorrect sequencing in Part 1
• Competing causes of death in Part 1
• Lack of a proper underlying cause of death
• A mechanism of death, without an underlying cause
  of death
• One or more major errors in DNF

Source Burger et al., 2007
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Review of certificates in Vangaurd Minor errors
81.5 23.7 13.0 2.5 86.1

• 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
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• In total 91,7 of cases had at least one error!!

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Serious major errors and associated factors,
Academic Hospital in Cape Town
Characteristic OR 95 CI p-value
Sex 0.8017
Male 1.0 -
Female 1.0 0.8-1.4
Age 0.1260
Neonates 1.0 -
1 mth 4 yrs 1.4 0.1-21.4
5-14 2.5 0.1-122.3
15-24 7.3 0.3-203.4
25-34 3.2 0.1-78.7
35-44 4.5 0.2-108.7
45-54 5.3 0.2-124.9
55-64 3.8 0.2-90.4
65-74 6.2 0.3-147.3
75 7.0 0.3-168.0


Characteristic OR 95 CI p-value
Department 0.5375
Casualty 1.0 -
Medical general 1.8 1.2-2.8
Medical specialised 2.0 1.2-3,2
Surgical 1.4 0.9-2.2
Neonates 3.3 0.2-62.8
Cause of death lt0.001
Neoplasms 1.0 -
Circulatory 3.4 2.1-5.5
Infectious/parasitic 4.3 2.3-8.0
Respiratory 4.7 2.5-9.0
Endocrine/nutrtional/metab 17.2 8.7-34.0
Digestive 6.3 3.1-12.9
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
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HIV test information from medical record for
sub-sample
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Brief intervention for internsProportion with
adequate score
N Pre-test Post-test McNemars p-value
Overall group 24 13 88 lt0.0001
Intervention group 13 15 84 0.0027
Control group 11 9 91 0.0027
Source Pieterse et al., 2008
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http//who.int/bookorders www.healthmetricsnetwork
.org healthmetrics_at_who.int
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Domains of Measurement
Determinants of Health Socio-economic and
demographic factors Environmental and behavioural
risk factors Service seeking behaviours
Health status Mortality Morbidity/ Disability W
ell-being
Health System Inputs Outputs
Outcomes Policy
Information Coverage Financing
Service Utilisation
Human resources (availability
Organisation and quality)

Source Health Metrics Network
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http//www.who.int/classifications/icd/en/
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• 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