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 Males HIV Females

200 200 150 100 150 100 50 0 0-4 5-14 15-24 25-34 35-44 45-54 55-64 65-74 75+ 50 0 0-4 5-14 15-24 25-34 35-44 45-54 55-64 65-74 75+ 2001 2004 2006

Source: Western Cape BOD project using City of Cape Town mortality data

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 Diabetes mellitus Stroke 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 1400 1200 1000 800 600 400 200 0 HIV/AIDS Other Communicable/mat/peri/nutrition Non-communicable diseases Injuries

Leading causes of premature mortality, Cape Town 2006

2006

HIV/AIDS Homicide Tuberculosis Road traffic Lower Respiratory infections Ischaemic heart disease Stroke Diabetes Mellitus Low birth weight and RDS Diarrhoeal Diseases 0 4.1

3.7

3.4

2.9

3.4

2.5

5 5.3

8.4

10 Percentage Source: Western Cape BOD project using City of Cape Town mortality data 14.4

Percentage of total Years of Life Lost (YLLs) 15 16.1

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 Approximate Part 1 Enter the diseases, injuries or complications that caused the death. Do not enter the interval between mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. List only one cause onset and death on each line.

IMMEDIATE CAUSE (a) …………………………...………

(Days/Months/Years) Immediate cause

on top line (Final disease or condition Due to, (or as a consequence of) resulting in death Sequentially list condition, if any, leading to (b) ………………………….………. immediate cause. Enter Due to, (or as a consequence of) with underlying cause UNDERLYING CAUSE last (c) ………………………………….

D

ue 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

.……………………………… ………………. ……………….

Contributing cause

but not in causal sequence in Part 2 __________________________________________________________________________________ FOR OFFICE USE ONLY ICD-10

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. Acute renal failure

IMMEDIATE CAUSE (a) …………………………...……… (Final disease or condition Due to, (or as a consequence of) resulting in death Sequentially list condition,

Hyperosmolar nonketotic coma

if any, leading to (b) ………………………….………. immediate cause. Enter Due to, (or as a consequence of) UNDERLYING CAUSE last

Diabetes mellitus, non-insulin dependent

D

ue 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 Hypertension, Previous myocardial infarction

__________________________________________________________________________________

Approximate interval between onset and death (Days/Months/Years)

5 Days ………………. 8 Days ……………….. 15 Years ………………. ………………. ………………. FOR OFFICE USE ONLY ICD-10

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.

(Final disease or condition Due to, (or as a consequence of) resulting in death Sequentially list condition,

Fractured Left Neck of Femur

if any, leading to (b) ………………………….………. immediate cause. Enter Due to, (or as a consequence of) UNDERLYING CAUSE last

D

ue 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)

………………. 4 weeks ……………….. 4 weeks ………………. ………………. ………………. FOR OFFICE USE ONLY ICD-10

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.

(Final disease or condition Due to, (or as a consequence of) resulting in death Sequentially list condition, immediate cause. Enter Due to, (or as a consequence of) UNDERLYING CAUSE last (c) ………………………………….

D

ue 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)

………………. ……………….. ………………. ………………. ………………. FOR OFFICE USE ONLY ICD-10

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. Stroke

IMMEDIATE CAUSE (a) …………………………...……… (Final disease or condition Due to, (or as a consequence of) resulting in death Sequentially list condition,

Pneumonia

immediate cause. Enter Due to, (or as a consequence of) UNDERLYING CAUSE last (c) ………………………………….

D

ue 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)

………………. ……………….. ………………. ………………. ………………. FOR OFFICE USE ONLY ICD-10

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.

(Final disease or condition Due to, (or as a consequence of) resulting in death Sequentially list condition, if any, leading to (b) ………………………….………. immediate cause. Enter Due to, (or as a consequence of) UNDERLYING CAUSE last (c) ………………………………….

D

ue 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)

………………. ……………….. ………………. ………………. ………………. FOR OFFICE USE ONLY ICD-10

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

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

S00 – T99

V01 – Y98

Z00 – Z99

ICD – 10 Chapters

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

Nature of injury

External causes of morbidity and mortality

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

TB - m ale

1996 2000/01 sample 700 600 500 400 300 200 100 0

TB - fem ale

300 250 200 150 100 50 0 Source: Groenewald et al, 2005 1996 2000/01 sample

Death certification quality in Cape Winelands and Overberg: Percentage ill-defined causes of death by sub-district

30 25 20 15 10 5 0 2004 2005 2006 Breede River Winelands Breede Valey 26 27 20 10 10 13 Drakenstein 9 Stellenbosch 9 Witzenberg Cape Agulhas Overstrand 7 7 17 14 12 13 12 8 10 Swellen 15 14 10 Theewaters 10 7 10

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

43.4%

Source: Burger et al., 2007

Review of certificates in Vangaurd : Minor errors

• Absence of a time estimate between onset of disease and death

81.5% 23.7%

• Use of abbreviations • Recording of inappropriate information

13.0%

• Illegible handwriting

2.5%

• One or more minor errors in DNF Source: Burger et al., 2007

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

Sex

Male 1.0

Female 1.0

Age

Neonates 1.0

1 mth – 4 yrs 1.4

5-14 2.5

15-24 7.3

25-34 35-44 45-54 3.2

4.5

5.3

55-64 65-74 75+ 3.8

6.2

7.0

95% CI 0.8-1.4

0.1-21.4

0.1-122.3

0.3-203.4

0.1-78.7 0.2-108.7

0.2-124.9

0.2-90.4

0.3-147.3

0.3-168.0

Source: Nojilana et al., 2008 p-value

0.8017

0.1260

Characteristic OR

Department

Casualty Medical general Medical specialised Surgical Neonates

Cause of death

Neoplasms Circulatory Infectious/parasitic Respiratory 1.0

3.4

4.3

4.7

Endocrine/nutrtional/metab 17.2

Digestive 6.3

Perinatal conditions 3.4

Genitourinary 17.3

Other 5.8

1.0

1.8

2.0

1.4

3.3

95% CI 1.2-2.8

1.2-3,2 0.9-2.2

0.2-62.8

2.1-5.5

2.3-8.0

2.5-9.0

8.7-34.0

3.1-12.9

0.8-15.0

7.8-38.2

2.9-11.5

p-value

0.5375

<0.001

HIV test information from medical record for sub-sample

HIV -ve 6 242

Potentially HIV/AIDS related causes* 71

not tested for HIV 33 38 Tested for HIV 32 HIV +ve 6 not reported on death certificate 15 17 recorded on death certificate not recorded on death certificate 0 recorded on death certificate

Brief intervention for interns

Proportion with adequate score

Overall group

N

24

Pre-test %

13

Post-test %

88

McNemar’s p-value

<0.0001

Intervention group 13 15 84 0.0027

Control group 11 9 91 0.0027

Source: Pieterse et al., 2008

http://who.int/bookorders www.healthmetricsnetwork.org

[email protected]

Domains of Measurement

Determinants of Health

Socio-economic and demographic factors Environmental and behavioural risk factors Service seeking behaviours

Health status

Mortality Morbidity/ Disability

Health System

Inputs Outputs Outcomes

Policy Information Coverage Financing Service Utilisation Human resources (availability Organisation and quality) Well-being

Source: Health Metrics Network

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