Transcript Measuring maternal mortality using census data in developing countries

Measuring maternal
mortality using census data
in developing countries
Tiziana Leone
LSE
Department of Social Policy
Outline
 Definitions
 Background
 Objectives
and rationale
 Lesotho and Nicaragua
 Methods
 Results
 Discussion and future work
Definition
A maternal death is the death of a woman while
pregnant or within 42 days of termination of
pregnancy, irrespective of the duration and
the site of the pregnancy, from any cause
related to or aggravated by the pregnancy or
its management but not from accidental
causes.
WHO, 1993
Measures of Maternal Mortality
# maternaldeaths
MMRatio 
X 100,000
# livebirths
# maternaldeaths
MMRate 
X 1,000
# women15  49
Background
Pressure to get the indicators right to
measure progress of MDG 5
 Vital registration not sufficient to record
maternal deaths
 Maternal mortality ‘rare’ event: sample
surveys need big sample in order to collect
enough information
 Census has been recommended in countries
that lack complete vital registration

Advantages and Disadvantages
using Census Data to Estimate
MMRate
Advantages:
•
•
•
•
No problems with sample size
It is possible to study differentials
Evaluation methods are well developed
It’s cheap!
Disadvantages:
•
•
•
•
Basic data need evaluation and adjustments
Only every 10 years (normally)
Methods Have Strong Assumption (e.g.:no migration)
Estimates are for intercensal period, not a specific period
Objectives
 Apply
methodology to two different
settings : Nicaragua and Lesotho
 Analyse feasibility of methods
 Develop methods in order to
estimate differential mortality
Lesotho and Nicaragua
Population
TFR
MMR
GDP
per
capita
Net
migration
HIV
prevalence
Lesotho
1.8m
3.5
730
$1,300
-0.78 ‰
23%
Nicaragua
5.7m
3.2
83-170
$2,600
-1.13‰
0.2%
Data
 Nicaragua
1995-2005 census
 Lesotho 1986-1996 census
Questions included in
Lesotho census questionnaire
Questions included in Nicaragua
census questionnaire
Methods
Series of evaluations methods based on
demographic
‘indirect
techniques’
with
adjustments when needed. Hill et al 2001.
Check degree of death coverage in the population
General Growth Balance
Check quality of fertility data
P/F Ratio
Check quality of information on pregnancy related
deaths
No formal methods.
General growth balance
Based on the balance population equation
r = b – d or (rearranging)
b–r=d
b=crude birth rate
r=growth rate
d=crude death rate.
Assumes absence of migration and that the completeness of
coverage of the deaths is c, constant at all ages.
The observed age-specific mortality rates are therefore equal to the
true rates multiplied by c, or that the true rates are equal to the
observed rates divided by c:
b(x+) – r(x+) = {1/c}*dobs(x+)
C=adjustment factor calculated using regression models
Mortality Check
General Growth Balance - Lesotho, female, 1986-1996
General Growth Balance - Nicaragua, female, 1995-2005
0.0400
0.0600
0.0500
Entry - Growth Rate x+
Entry - Growth Rate x+
0.0300
0.0400
0.0300
0.0200
Observed values
0.0200
Observed values
Fitted values
0.0100
Fitted values
0.0100
0.0000
0.0000
0.0050
0.0100
0.0150
0.0200
Death Rate x+
0.0250
0.0300
0.0000
0.0000
0.0100
0.0200
0.0300
Death Rate x+
Regression line fitted for (5+)-(65+)
0.0400
0.0500
Fertility Check
Age specific fertility rates Nicaragua, 2005
ASFR, Lesotho 1996
0.1400
0.2000
0.1800
0.1200
0.1600
0.1000
0.1400
0.1200
0.0800
0.1000
0.0600
0.0800
0.0400
0.0600
0.0400
0.0200
0.0200
0.0000
0.0000
15-19
20-24
25-29
30-34
35-39
40-44
45-49
15-19
20-24
25-29
30-34
35-39
40-44
45-49
Plausibility checks
Proportions of Births and Pregnancy-Related Deaths,
Nicaragua 2005
0.40
0.40
0.35
0.35
0.30
0.30
Proportion
Proportion
Proportions of Births and Pregnancy-Related Deaths,
Lesotho 1996
0.25
0.20
0.15
Births
Preg-Related Deaths
0.25
0.20
0.15
0.10
Births
0.10
0.05
Preg-Related Deaths
0.05
0.00
0.00
0
1
2
3
Age Group
4
5
6
0
2
4
Age Group
6
8
MMR
Census
Lesotho
UNICEF
estimate
UNDP
532 (1996) 550 (2000) 530 (1996)
Nicaragua 135 (2005) 170 (2005) 230 (2000)
Age specific PRMR
AgePRMP,
SpecificNicaragua
PRMR, Nicaragua
2005 age range
Age spefic
2005-shorter
1000
300
2500
800
250
2000
600
200
400
150
200
100
PRMR
PRMR
Age specific PRMR, Lesotho 1996
1500
Series1
1000
500
50
0
15-19
20-24
25-29
Age
30-34
0
35+
0
15-19
15-19
20-24
20-24
25-29
30-34
25-29 Age
35-39
30-34
40-44
35-39
45-49
Discussion
We are estimating an intercensal value and not a
specific period
Careful interpretation of results
We need to explore more ways to get formal methods
to estimate pregnancy related deaths
Census data give reasonable estimates
Best way forward in absence of Vital registration
Very little additional information needed
Need for more advocacy and training
Future plans

Apply the same methodology to more countries (e.g.
South Africa and Zimbabwe)


Two points in time
Differential (e.g.: wealth, residence, region) mortality
applying smoothing functions