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BDAP-Burden of
Disease Analysis Project |
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A computational tool for
Burden of Disease Study |
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Introduction |
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Summary measures of
population health have a variety of potential uses for monitoring of population health.
Estimation of Burden of Disease is the first step towards computation of summary measures.
The disability adjusted life years (DALYs) computed in a burden of disease study,
is itself a summary measure of health gap. DALY components like the years lived with
disability (YLD) can be combined with life table functions to compute health
expectancy measures like the disability adjusted life expectancy (DALE). Any burden
of disease study requires substantial efforts to gather and collate information on causes
of death, descriptive epidemiology of each of the disease condition included in the study,
as well as community valuations of time lived in the respective health state. Gathering
the inputs for computation of disease burden for any population is itself a time consuming
task requiring a lot of team work. But the task of estimating burden of disease for a
population is hardly over with availability of inputs for computation of disease burden.
One practical problem is the daunting computational load on the researchers who take up to
generate these estimates. The BDAP software has been designed to reduce this computational
load, so that researchers can focus on more productive tasks of gathering inputs as well
as analysis of results. |
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About Software |
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BDAP software uses a Visual
Basic Multi Document Interface application at the frontend and a Microsoft Access database
that serves as the backend. A number of utilities have been built into the application
that permits data sourcing through different modes(data entry, clipboard, import etc.) and
file formats (.WK1,.XLS,.DBF, .MDB,.TXT etc.)and the user interface has been designed to
make the process of generating disease burden very simple. The software gives the user to
save results in any of the aforesaid file formats.The software comprises of 36 screens and
25 modules. BDAP can be operated on Windows9x, WindowsNT(Server and Workstation). |
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Inputs and Results
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For each Basic Population Unit(BPU) in
the study the following inputs have to be entered. |
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- Demographic data.
- Population.
- Age Specific Death Rates (ASDR).
- Coale and Demeney Model life table
- Population Growth Rate
- Infant Mortality Rate
- Cause Specific Mortality Proportions
- Epidemological data
- Disability Weights
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After this data is entered
BDAP can calculate DALYs for one or more sets of discounting and age weighting parameters.
Computation of DALYs involves computation of YLLs and YLDs separately for each cause of
burden. Availability of YLDs from DALY computations enables computation of DALE. |
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After DALE is computed,
results can be obtained for each BPU or by different levels of population aggregation and
the summary measure of population health. |
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- Percentage distribution of YLL By Specific cause.
- YLLs by Age, Sex and Cause.
- YLDs by Age, Sex and Cause.
- DALE Results.
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The entire range of results
can be viewed in the form of graphs, which can also be exported. BDAP includes the
facility to view graphs for different components of the sensitivity analysis. |
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Tools |
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The tools menu permits independent
calculations of some of the intermediate values that go into computation of estimates of
disease burden. The tools that are available in BDAP are |
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- Life Tables:This
permits building of life tables according to one of several methods and according to
different age groups. By defining the demographic parameters, specifying the age groups,
and entering the ASDRs for each age group, it is possible to generate life tables using
any of the four methods namely Standard-Newell Colin, Keyfitz, Reed Merrell,
Greville.
- YLL Calculator: In
case a researcher has only the numner of deaths that have occurred due to a specific
cause, and does not have data on the other inputs that are required for computing disease
burden estimates in terms of DALYs, this tool permits computation of the YLLs due to that
specific cause.
- YLD Calculator: A calculator similar as above, this calulator is used for
calculating YLDs due to individual causes.
- Interpolator: This tool is used to interpolate either population (or) deaths data available
in five year age groups to single year age group using an osculatory method and sprague's
coefficients .The results can then be recovered according to output age groups to be
defined by the user.
- Age at Death in an Open Interval
: This tool calculates Age at Death for different
Beginning of Age Intervals(BOAI) by using the Coale and Demeney Model life table,
Population Growth Rate and Deaths above 10 and Deaths above 45 figures.
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Updated on 17/10/2001
by John Paul Chakalackal |
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