Combining health and social protection measures to reach the ultra ...

Decision-making
was prior to 2001, a time series of annual life tables
(adjusted if the registration level was incomplete) between
1985 and the latest available year was used to project
levels of child and adult mortality for 2001. For small
countries with populations of less than 500 000, moving
averages were used to smooth the time series. Projected
values of child and adult mortality were then applied to a
modified logit life table model 6 , using the most recent
national data as the standard, to predict the full life table
for 2001, and HIV/AIDS and war deaths were added to
total mortality rates for 2001 where necessary. This
method was applied for 40 countries using a total of 711
country-years of death registration data.
✜ Countries with other information on levels of child and
adult mortality. For 37 countries, estimated levels of
child and adult mortality were applied to a modified logit
life table model 6 , using a global standard, to estimate the
full life table for 2001, and HIV/AIDS deaths and war
deaths were added to total mortality rates as necessary.
For most of these countries, data on levels of adult
mortality were obtained from death registration data,
official life tables, or mortality information derived from
other sources such as censuses and surveys. The allcause
mortality envelope for China was derived from a
time series analysis of deaths for every household in
China reported in the 1982, 1990, and 2000 censuses.
The extent of underreporting of deaths in the 2000
census was estimated at about 11.3% for males and
18.1% for females 1 . The all-cause mortality envelope for
India was derived from a time series analysis of agespecific
death rates from the sample registration system
after correction for underregistration (88%
completeness) 8 .
✜ Countries with information on levels of child mortality
only. For 55 countries, 42 of them in sub-Saharan
Africa, no information was available on levels of adult
mortality. Based on the predicted level of child mortality
in 2001, the most likely corresponding level of adult
mortality (excluding HIV/AIDS deaths where necessary)
was selected, along with uncertainty ranges, based on
regression models of child versus adult mortality as
observed in a set of almost 2000 life tables judged to be
of good quality 2,6 . These estimated levels of child and
adult mortality were then applied to a modified logit life
table model, using a global standard, to estimate the full
life table in 2001, and HIV/AIDS deaths and war deaths
were added to total mortality rates as necessary.
Evidence on adult mortality in sub-Saharan African
countries remains limited, even in areas with successful
child and maternal mortality surveys.
Classification of causes of disease and injury
Disease and injury causes of death and of burden of disease
were classified using the same tree structure as in the original
GBD study 7 . The first level of disaggregation comprises the
following three broad cause groups:
✜ Group I: communicable, maternal, perinatal, and
nutritional conditions;
✜ Group II: noncommunicable diseases;
✜ Group III: injuries.
Each group was then divided into major cause
subcategories, for example, cardiovascular disease (CVD) and
malignant neoplasms (cancers) are two major cause
subcategories of Group II. Beyond this level, two further
disaggregation levels were used, resulting in a complete
cause list of 135 categories of specific diseases and injuries.
Group I causes of death consist of the cluster of conditions
that typically decline at a faster pace than all-cause mortality
during the epidemiological transition. In high-mortality
populations, Group I dominates the cause of death pattern,
whereas in low-mortality populations, Group I accounts for
only a small proportion of deaths. The major cause
subcategories are closely based on the ICD chapters with a
few significant differences. Whereas the ICD classifies chronic
respiratory diseases and acute respiratory infections into the
same chapter, the GBD cause classification includes acute
respiratory infections in Group I and chronic respiratory
diseases in Group II. Note also that the Group I subcategory
of “causes arising in the perinatal period” relates to the
causes included in the corresponding ICD chapter, principally
low birth weight, prematurity, birth asphyxia, and birth
trauma, but does not include all causes of deaths occurring
during the perinatal period, such as infections, congenital
malformations, and injuries. In addition, the GBD includes
only deaths among children born alive and does not
estimate stillbirths.
The GBD classification system does not include the ICD
category “Symptoms, signs, and ill-defined conditions” as one
of the major causes of deaths. The GBD classification scheme
has reassigned deaths assigned to this ICD category, as well
as some other codes used for ill-defined conditions, to
specific causes of death. This is important from the
perspective of generating useful information to compare
cause of death patterns or to inform health policy-making,
because it allows unbiased comparisons of cause of death
patterns across countries or regions.
Deaths are categorically attributed to one underlying cause
using ICD rules and conventions. In some cases where the
ICD rules are ambiguous, the GBD 2001 follows the
conventions used by the GBD 1990 study 7 . It should also be
noted that a number of causes of death act as risk factors for
other diseases. Total mortality attributable to such causes
may be substantially larger than the mortality estimates for
the cause in terms of ICD rules for underlying causes. For
example, the GBD 2001 estimates that 960 000 deaths were
due to diabetes mellitus as an underlying cause, but when
deaths from CVD and renal failure attributable to diabetes are
included, the global total of attributable deaths rises to almost
3 million 9 . Other causes for which important components of
attributable mortality are included elsewhere in the GBD
cause list include hepatitis B or C (attributable liver cancer
and renal failure), unipolar or bipolar depressive disorders
and schizophrenia (attributable suicide), and blindness
(mortality attributable to blindness whether from infectious or
non-infectious causes).
164 ✜ Global Forum Update on Research for Health Volume 4