Evaluation of Mortality Data Collected from
Population Censuses
United Nations Statistics Division
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Outline of the presentation
Some basics about life table
For two items that can be used to obtain mortality statistics in
census:
-
Survival of children ever born
-
Deaths in the household
We discuss
- Information collected
- Possible quality issues related to each question
- Methods of data evaluation using examples
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Some basics about life table (1)
Age (x)
nMx
nqx
lx
nLx
ex
0
0.005774
0.00579
100000
99707
79.1561
1
0.000284
0.001134
99581
398184
78.4879
5
9.32E-05
0.000466
99511
497465
74.5417
10
0.000166
0.000831
99475
497260
69.5677
…
…
…
…
…
…
55
0.007521
0.036913
93619
462988
26.9352
60
0.011885
0.057709
91576
449140
22.4803
65
0.021682
0.102837
88080
429485
18.2733
70
0.037063
0.1696
83714
407728
14.096
75
0.059397
0.258588
79377
383688
9.72956
80
0.10245
0.407803
74098
354340
5.24461
85+
0.179314
1
67638
34275
0.50674
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Some basics about life table (2)
nMx = period mortality rate =
# deaths died between age x and age x  n
average number of persons alive aged x and x  n
nqx = proportion of those people reaching their xth birthday who die before their
(x+n)th birthday
lx = number of person who live to their xth birthday
nLx = number of person-years lived between exact ages x and x+n
ex = life expectancy at age x (the average number of years which people have
left to live when they are at age x)
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Some basics about life table (3)
Model life tables
•
Created to estimate demographic parameters for countries with
limited data
•
Built on empirical studies of age-specific mortality patterns in the
past
•
Two groups of model life tables:
• Coale-Demeny: based on European populations
• North, South, East and west European models
• United Nations: For developing countries
• Latin American, Chilean, South Asian, Far Eastern,
General
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Mortality statistics from population census – Introduction
A group of questions can be used to obtain mortality data in a census
Two distinctions:
a)
b)
Level and trend of mortality vs age pattern of mortality
•
Survival of children ever born: level and trend of mortality
•
Household deaths: age pattern of mortality:
Deaths of younger persons vs. deaths of adults
•
Younger persons: survival of children ever born
•
Adults: household deaths
All approaches are to supplement death registration data, not to replace it.
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – information collected
Have been used for the past 50 years to collect data on infant and
child mortality
For every woman the following information are collected:
a) the total number of female children she has borne in her lifetime.
b) the total number of male children she has borne in her lifetime.
c) the number of female children who are surviving
d) the number of male children who are surviving
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – Use of
Ever born – Surviving = Children deceased
Children deceased / Ever born = Proportion deceased
Life table measures of infant, child and young adult mortality may be
derived from the proportion of deceased.
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born
- Tabulation example, Turkey 2000
Age
15 - 19
20 - 24
25 - 29
30 - 34
35 - 39
40 - 44
45 - 49
Women
Total CEB
Total CS
Proportion of
deceased
children
3518257
294628
281296
0.045
3263432
2078364
1991445
0.042
2918825
4522719
4312404
0.047
2457285
5700038
5395143
0.053
2400808
7036619
6563946
0.067
1985225
6707033
6131544
0.086
1658012
6394157
5722904
0.105
Source: Tabulated using data from United Nations Demographic Yearbook
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – Brass type estimates (1)
Data are used to estimate level and trend of mortality for
about 20 years prior to a census or survey.
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (2)
Empirical findings about child mortality
Age group of mother in
years
Age group index
Proportion of children dead
approximates
15-19
1
q(1)
20-24
2
q(2)
25-29
3
q(3)
30-34
4
q(5)
35-39
5
q(10)
40-44
6
q(15)
45-49
7
q(20)
50-54
8
q(25)
55-59
9
q(30)
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born - Brass-type estimates (3)
Empirical findings about child mortality
-
Approximation
-
q values referring to different time period before census
-
q(1): more recent estimates; q(20) – earlier estimates (Feeney,
1980)
-
Under-five mortality is used more often: more robust than infant
mortality
-
However if comparing estimates with civil registration, may use
infant mortality rate
Feeney 1980: Estimating infant mortality trends from child survivorship data, Population
Studies 34(1): 109-128.
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (4)
Empirical findings about child mortality
-
Under-five mortality
-
Most commonly used
-
more robust than infant mortality
-
Upward biases from reports of younger women, usually inaccurate
-
More powerful results (Brass type) came from multiple data sources
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (5)
An example of MortPak CEBCS output
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (5)
An example of MortPak CEBCS output (cont.)
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (6)
How to identify the right mortality model - graphical
Source: Step by step guide to the estimation of child mortality, 1990, United Nations
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (7)
How to identify the right mortality model – graphical
Source: Step by step guide to the estimation of child mortality, 1990, United Nations
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (8)
Illustration of the relationship of mother’s age and timing of the
under-5 mortality estimates
Bangladesh, 1974 Retrospective Survey of Fertility and Mortality
Source: Step by step guide to the estimation of child mortality, 1990, United Nations
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (9)
q(5) more robust than q(1)
Infant and under-five mortality, Bangladesh
Source: Step by step guide to the estimation of child mortality, 1990, United Nations
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (10)
Turkey example again
q(5), Turkey 2000 census
0.1
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
1987
1990
1993
1995
1997
1999
2000
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born: Brass-type estimates (11)
Comparison of multiple sources
q(5), Turkey
0.115
0.105
0.095
0.085
0.075
0.065
0.055
00
20
99
19
97
19
96
19
95
19
93
19
91
19
90
19
89
19
87
19
86
19
85
19
83
19
80
19
19
76
0.045
ye ar
2000 census Brass
1990 census Brass
1998 TDHS
2003 DHS
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
A few notes about Brass type estimates
• Almost smooth due to modeling
• If see rough and unsmooth data, indicates quality issues
• The last increase of q(5) does not mean increasing mortality, but
rather biases generated from mother of young age groups (15-19)
• There is violation of assumptions about age patterns in the
method, i.e., child death depends on children’s age only. But
children born to very young mothers tend to be disadvantaged
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality (1)
Experience has shown that it is possible to get high quality responses to
this kind of questions in any data collection exercise, including
censuses.
If both CEB and CS are understated, some cancellation of errors will
occur.
But in practice, reporting of CS is more likely to be complete than
reporting of CEB => calculated proportions of deceased children are
likely to be too low.
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality (2)
Other influences on the accuracy of estimates derived from these data:
Assumptions about the age pattern of mortality: mortality of child relies
only on their own age (which will fail at young age of mothers, i.e., the
1st or 2nd age groups of mothers)
In the ideal case, data on CEB and CS will be available from two or more
data collection exercises, at different points in time.
This will allow comparison, providing a powerful test of the quality of the
estimates.
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality assessment (1)
-
Initial assessment:
- Any missing values in children surviving data?
- Missing values for any relevant variables: age of mother, sex of those
who died
- Plausibility of data
- Children survival data; age distribution
- Distribution of women with socio-economic characteristics
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality assessment (2)
Example: missing or implausible values of CEB and CS data
“… systematic failure in data collection…”
Source: Estimation of mortality using the South African Census 2001 data, Dorrington, Moultrie and
Timæus, Centre of Actuarial Research, University of Cape Town, 2001
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality assessment (5)
Comparing age patterns of proportion deceased children
Proportion of deceased children, Turkey
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
15 - 19
20 - 24
25 - 29
30 - 34
35 - 39
40 - 44
45 - 49
Age of mother
1990 census
1998 DHS
2000 census
2003 DHS
Source: Graph produced based on data collected by the United Nations Demographic Yearbook and Measure
DHS country report
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality assessment (6)
A rapid assessment: Burundi, 1990 census: CS and CEB data
Age
Total women
Average CEB
Average CS
CS/CEB
15 +
1483895
3.82
2.93
0.77
15 - 19
250329
0.07
0.07
0.89
20 - 24
229655
1.02
0.86
0.84
25 - 29
214467
2.75
2.28
0.83
30 - 34
187348
4.49
3.63
0.81
35 - 39
135551
5.62
4.51
0.80
40 - 44
97537
6.10
4.85
0.80
45 - 49
75526
6.23
4.89
0.79
50 - 54
76100
6.21
4.70
0.76
55 - 59
50817
6.22
4.58
0.74
60 - 64
53775
6.12
4.28
0.70
110062
6.07
3.82
0.63
2728
4.47
3.37
0.76
65 +
Unknown
Source: Graph produced based on data collected by the United Nations Demographic Yearbook
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality assessment (7)
A rapid assessment of CEB and CS data
- (1-0.81)=0.19 for the 30-34 age group: the proportion of
deceased among all children born to mother of 30-34 years of
age ≈ q(5), the proportion of children born who die before
their 5th birthday 7 years prior to census
- Compare with other estimates, e.g., UN Population Division
estimates of under-5 mortality
- 1990 census estimates of under-5 child mortality = 190 per
1000 for 1983
- UN Pop Division estimates for the period 1980-1985: 196 per
1000
- Slightly underestimates
Method: Rapid Assessment of Census Data on Children Born and Surviving, Griffith Feeney, 2009.
http://www.demographer.com/rapid-assessment-of-ceb-and-cs-data/
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality assessment (8)
Comparing with UN Population Division under-five mortality
estimates
Source: World Population Prospects: The 2010 Revision
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Survival of children ever born – quality assessment (9)
Existing external sources
- UN population division (World Population Prospect)
- UNICEF child mortality website (www.childmortality.org)
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Household deaths in the last 12 months – adult mortality (1)
- Direct estimates of current death rates can be obtained, however,
with substantial errors
- Under-reporting, especially for child deaths and older age deaths
- Reference period errors in reporting of deaths (versus the usual 12
months reference period)
- Death question omitted by interviewers
- Household breaking up due to the death of a senior household
member
- Age-heaping and age exaggeration
-
The method is mainly used for adult mortality
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Household deaths in the last 12 months – adult mortality (2)
Initial assessment
Tabulation of enumerated deaths with associated variables, e.g., year/month
of death
•
Quality of age reporting for the deceased
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Household deaths in the last 12 months – adult mortality (4):
Comparing age-specific death rates
Age specific death rate, Madagascar, Male
16
14
12
10
8
6
4
2
0
15 - 19
20 - 24
25 - 29
30 - 34
35 - 39
40 - 44
45 - 49
Age
Male, 1993 census
Male, 1992 DHS
Male, 1997 DHS
Source: Graph produced based on data collected by the United Nations Demographic Yearbook and Measure
DHS country report
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Household deaths in the last 12 months – adult mortality (3)
Assessment: death distribution methods
General Growth Balance (GGB), assumes
•
constant coverage of household deaths and population across all ages (this
would not work for children deaths)
•
Negligible migration
•
Stable population (constant births and deaths)
•
Accurate reporting of age for both population and deaths
Synthetic Extinct Generations method (SEG), assumes
•
All the above, except for stable population assumption was relaxed in later version
•
Constant coverage of population across time (may be relaxed if use a “combined
GGB-SEG approach”)
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Household deaths in the last 12 months – adult mortality (4)
Assessment: example of GGB method
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011
Household deaths in the last 12 months – adult mortality (5)
Assessment: example of GGB method
f: slope of the fitted line
(1/f)*100% = 41.2% 
only 41.2% of the
deaths were being
reported
United Nations Sub-Regional Workshop on Census Data Evaluation
Phnom Penh, Cambodia, 14-17 November 2011