# Spreading population growth by period

Hi all,

We have a couple of programs that look at their population coverage indicators each month (e.g. ANC 1 coverage rate), yet we only update populations once a year (entering the data or adding projected figures in January).

The problem is when you look at coverage monthly you always see a dip in January (see chart below). Is there an established way to spread the population by period? I’ve got the aggregation operator for the Population data element set to “Average” – but presumably that would only have an impact on yearly data if we were analyzing more than 1 year.

I can smooth this outside of DHIS-2 by dividing the annual population growth rate by 12 and applying a monthly increase to the January population before calculating coverage. What are the other options?

We could enter monthly population projections into the DHIS-2 – but seems like a lot of extra effort and at the facility level they only re-estimate population once a year.

Randy Wilson

We face exactly the same issue,except it is even more problematic because we are analyzing primarily weekly data. Our solution has been exactly as you have written, to create and import the facility catchment population externally and import. It is a bit of effort but only needs to be done once. A better solution would be preferable though.

Regards,

Jason

···

Sent from my mobile

On Apr 3, 2014 12:43 PM, “Wilson,Randy” rwilson@msh.org wrote:

Hi all,

We have a couple of programs that look at their population coverage indicators each month (e.g. ANC 1 coverage rate), yet we only update populations once a year (entering the data or adding projected figures in January).

The problem is when you look at coverage monthly you always see a dip in January (see chart below). Is there an established way to spread the population by period? I’ve got the aggregation operator for the Population data element set to “Average” – but presumably that would only have an impact on yearly data if we were analyzing more than 1 year.

I can smooth this outside of DHIS-2 by dividing the annual population growth rate by 12 and applying a monthly increase to the January population before calculating coverage. What are the other options?

We could enter monthly population projections into the DHIS-2 – but seems like a lot of extra effort and at the facility level they only re-estimate population once a year.

Randy Wilson

dHi,

to me it sounds like storing monthly (or quarterly) population data in the system would be the only short/medium-term solution. It will work fine as long as data element aggregation operator is set to average.

This to me sounds like an ideal candidate for an app - one that takes i) the org unit level for the yearly population data and ii) the growth rate as input, then applies a linear data addition along the 12 months to make more realistic population data, writes that monthly data back to the system and removes the yearly data after verification.

Or less sexy, a bash and curl script against the web api.

Lars

···

On Thu, Apr 3, 2014 at 1:11 PM, Jason Pickering jason.p.pickering@gmail.com wrote:

We face exactly the same issue,except it is even more problematic because we are analyzing primarily weekly data. Our solution has been exactly as you have written, to create and import the facility catchment population externally and import. It is a bit of effort but only needs to be done once. A better solution would be preferable though.

Regards,

Jason

Sent from my mobile

On Apr 3, 2014 12:43 PM, “Wilson,Randy” rwilson@msh.org wrote:

Hi all,

We have a couple of programs that look at their population coverage indicators each month (e.g. ANC 1 coverage rate), yet we only update populations once a year (entering the data or adding projected figures in January).

The problem is when you look at coverage monthly you always see a dip in January (see chart below). Is there an established way to spread the population by period? I’ve got the aggregation operator for the Population data element set to “Average” – but presumably that would only have an impact on yearly data if we were analyzing more than 1 year.

I can smooth this outside of DHIS-2 by dividing the annual population growth rate by 12 and applying a monthly increase to the January population before calculating coverage. What are the other options?

We could enter monthly population projections into the DHIS-2 – but seems like a lot of extra effort and at the facility level they only re-estimate population once a year.

Randy Wilson

dHi,

to me it sounds like storing monthly (or quarterly) population data in the
system would be the only short/medium-term solution. It will work fine as
long as data element aggregation operator is set to average.

This to me sounds like an ideal candidate for an app<http://www.dhis2.org/doc/snapshot/en/user/html/ch29.html&gt;\- one that takes i) the org unit level for the yearly population data and
ii) the growth rate as input, then applies a linear data addition along the
12 months to make more realistic population data, writes that monthly data
back to the system and removes the yearly data after verification.

Sounds like a way to do it. I think I'd maybe leave the yearly population
rather than delete it and name the calculated dataelements slightly
different.

The alternative would be to do something smart with the indicator
calculation eg. an option to say use the extrapolated (or interpolated for
previous years) value from the yearly dataelement when it is being combined
in calculation with a monthly. It should be possible to linearly
extrapolate on the fly on the basis of previous year's value.

Though persisting the monthly values from the calculation is probably
simpler and easier on the database.

Or less sexy, a bash and curl script against the web api.

Even less sexy bash + psql against the database

···

On 3 April 2014 18:11, Lars Helge Øverland <larshelge@gmail.com> wrote:

Lars

On Thu, Apr 3, 2014 at 1:11 PM, Jason Pickering < > jason.p.pickering@gmail.com> wrote:

We face exactly the same issue,except it is even more problematic because
we are analyzing primarily weekly data. Our solution has been exactly as
you have written, to create and import the facility catchment population
externally and import. It is a bit of effort but only needs to be done
once. A better solution would be preferable though.

Regards,
Jason

--
Sent from my mobile
On Apr 3, 2014 12:43 PM, "Wilson,Randy" <rwilson@msh.org> wrote:

Hi all,

We have a couple of programs that look at their population coverage
indicators each month (e.g. ANC 1 coverage rate), yet we only update
populations once a year (entering the data or adding projected figures in
January).

The problem is when you look at coverage monthly you always see a dip in
January (see chart below). Is there an established way to spread the
population by period? I've got the aggregation operator for the Population
data element set to "Average" - but presumably that would only have an
impact on yearly data if we were analyzing more than 1 year.

I can smooth this outside of DHIS-2 by dividing the annual population
growth rate by 12 and applying a monthly increase to the January population
before calculating coverage. What are the other options?

We could enter monthly population projections into the DHIS-2 - but
seems like a lot of extra effort and at the facility level they only
re-estimate population once a year.

*Randy Wilson*

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