who and ihme estimates of tb disease burden: comparison ......who and ihme estimates of tb disease...
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WHO and IHME estimates of TB disease burden:
Comparison of methods and results
Global Task Force on TB Impact Measurement
3rd meeting of the TB estimates subgroup
Glion-sur-Montreux, 31 March- 2nd April 2015
Laura Anderson
Philippe Glaziou
GLOBAL TB PROGRAMME
Outline
• Comparison of methods: Key points only
• What can be compared?
• Comparison of results: Key points only
• Additional analysis to help understand results
Topic WHO IHME
Main data sources Notifications (All countries)
VR data (2170 country-years)
Prevalence survey data (national)
(15 countries)
Tuberculin surveys (3 countries)
Inventory study results (n=5)
10 predictive covariates (e.g. GDP
per capita, u5MR, HIV prevalence)
Notifications (All countries)
VR (2731 country-years)
VA data (166 site-years)
Prevalence survey data
(national and sub-national)
(24 countries)
11 predictive covariates (e.g.
smoking prevalence, diabetes,
indoor air pollution, alcohol
and health system access)
Population estimates
and mortality envelope
UN Population Division
57 million deaths in 2013
IHME population estimates
53 million deaths in 2010
Comparison of WHO and IHME methods for all
indicators
Comparison of WHO and IHME methods for all
indicators
Variable WHO IHME
Overall analytical
/model
framework
Internally consistent models
combining different data
sources
Uncertainty documented
No age standardisation
Bayesian model (Dismod MR-2.0)
WHO TB burden estimates of case
detection rate are used for some
of the priors
Uncertainty documented
Standardised for age
Country
consultations?
Burden estimates shared with
all countries for review each
year plus other in-depth
reviews
Reproducibility by
others
Not reproducible: some raw
data not published, computer
code not published
Not reproducible: raw country
data and computer code not
publicly available
What could we compare?
• 153 countries and territories for incidence and 187 for prevalence and
mortality, 98% global population
• Rates only (not absolute numbers)
• TB incidence and mortality (HIV negative ) 1990-2013
• TB incidence (HIV positive and negative), 2013
• TB prevalence (HIV negative and positive), 1990 -2013
• Age standardised IHME with non-age standardised WHO
Incidence and prevalence: Country-specific estimates were provided for 1990, 1995, 2000, 2005,
2010 and 2013. Linear interpolation was used to complete time-series.
Key Results
WHO (blue) and IHME (red) estimates of global TB incidence,
mortality and prevalence rates, 1990−2013
WHO (blue) and IHME (red) estimates of HIV-negative TB
incidence rates by WHO region, 1990−2013
WHO (blue) and IHME (red) estimates of HIV-negative TB
incidence rates, four countries with robust TB surveillance
systems, 1990-2013
WHO and IHME estimates of HIV-negative TB incidence rates in
2013*
AFR AMR EMR
EUR SEA WPR
0
250
500
750
0
50
100
150
0
100
200
300
0
50
100
150
100
200
300
0
100
200
0 100 200 300 400 0 50 100 150 0 200 400 600
0 50 100 150 100 200 300 400 0 100 200 300 400Incidence rate (WHO)
Inc
ide
nc
e r
ate
(IH
ME
)
*22 high TB burden countries shown in red
China
WHO (blue) and IHME (red) estimates of HIV-negative TB
mortality rates by WHO region, 1990−2013
Mortality reduction 1990-2013
Reasonable agreement in regional aggregates
The red segments indicate weighted means for each WHO region (using population weights)
------------------------------------------ ------------------------------------------ ------------------------- ------------------------ --------------------- ---------------------
---------------------------------------------- ---------------------------------------------- --------- --------- -------------- -------------
AFR AMR EMR
EUR SEA WPR
-100
-50
0
50
100
150
-100
-50
0
50
100
150
WHO IHME WHO IHME WHO IHME
Mo
rta
lity
re
du
cti
on
(%
)
WHO (blue) and IHME (red) estimates of HIV-negative TB
mortality rates, four countries with robust TB surveillance
systems, 1990-2013
AFR AMR EMR
EUR SEA WPR
1
10
100
1
10
1
100
0.1
1.0
10.0
10
100
1
10
100
1 10 100 0.1 1.0 10.0 1e-41 1e-29 1e-17 1e-05
0.1 1.0 10.0 10 100 1 100Mortality (WHO)
Mo
rta
lity
(IH
ME
)WHO and IHME estimates of HIV-negative TB mortality rates by
WHO region, 2013 (log scale)
*22 high TB burden countries shown in red
China
WHO (blue) and IHME (red) estimates of TB prevalence rates by
WHO region, 1990−2013
Prevalence reduction by 2013 compared with the level of 1990
The red segments indicate weighted means for each WHO region (using population weights)
------------------------------------------ ------------------------------------------ ------------------------- ------------------------ --------------------- ---------------------
---------------------------------------------- ---------------------------------------------- --------- --------- -------------- -------------
AFR AMR EMR
EUR SEA WPR
-100
0
100
200
-100
0
100
200
WHO IHME WHO IHME WHO IHME
Pre
va
len
ce
re
du
cti
on
(%
)
Additional analysis to understand
differences between WHO and IHME
TB burden estimates
Different approaches to adjustment of prevalence survey data?
RWA 2012
NGA 2012
GMB 2012
PAK 2011
KHM 2011
LAO 2011
ETH 2011
CHN 2010
KHM 2002
MMR 2009
PHL 2007
VNM 2007
CHN 1990
CHN 2000
PHL 1997
100 200 300 400 500 1000 1500 2000
Prevalence per 100,000
AFR AMR EMR
EUR SEA WPR
0.00
0.25
0.50
0.75
1.00
1.25
0.1
0.2
0.3
0.4
0.0
0.2
0.4
0.6
0.0
0.1
0.2
0.3
0.4
0.1
0.2
0.3
0.4
0.1
0.2
0.3
0.4
0.5
0.1 0.2 0.3 0.4 0.1 0.2 0.3 0.4 0.5 0.1 0.2 0.3 0.4
0.0 0.1 0.2 0.3 0.4 0.1 0.2 0.3 0.4 0.0 0.1 0.2 0.3 0.4
CFR (WHO)
CF
R (
IHM
E)
Differences in relationship between incidence and mortality
(CFR)
AFR AMR EMR
EUR SEA WPR
25
50
75
100
0
30
60
90
120
40
60
80
100
120
140
25
50
75
100
75
100
125
100
200
25 50 75 100 40 60 80 100 60 80 100
70 80 90 100 40 60 80 100 40 60 80 100
CDR (WHO)
CD
R (
IHM
E)
Differences in relationship between notifications and incidence
(CDR)
Extra slides
WHO (blue) and IHME (red) estimates of HIV-negative TB
incidence rates, 22 high TB burden countries, 1990−2013
WHO (blue) and IHME (red) estimates of HIV-negative TB
mortality rates, 22 high TB burden countries, 1990−2013
WHO (blue) and IHME (red) estimates of TB prevalence rates,
22 high TB burden countries, 1990−2013
AFR AMR EMR
EUR SEA WPR
100
1000
10
100
100
10
100
10
100
100 1000 1 100 10 1000
1 10 100 100 1000 10 100 1000Prevalence (WHO)
Pre
va
len
ce
(IH
ME
)
WHO and IHME estimates of TB prevalence by WHO region,
2013 (log scale)
*22 high TB burden countries shown in red
AFR AMR
EMR EUR
SEA WPR
-0.10
-0.05
0.00
0.05
0.10
-0.10
-0.05
0.00
0.05
0.10
-0.10
-0.05
0.00
0.05
0.10
-0.3 -0.2 -0.1 0.0 0.1 0.2 0.3-0.3 -0.2 -0.1 0.0 0.1 0.2 0.3
dI/dt (WHO)
dI/
dt
(IH
ME
)
1990
1995
2000
2005
2010
year
WHO and IHME estimates of rates of change in HIV-negative TB
incidence by WHO region, 1990-2013