Terpase, ******************************* On 08/02/2008, Aluka Terpase <[EMAIL PROTECTED]> wrote: Hi Calle
I was going through some of the indicators and was unable to explain how we arrived at the denominator"SUM([Female under 1 year]) + SUM([Male under 1 year]) * 1.23" for calculating ANC coverage. Could you throw more light" ******************************* I am echoing this reply to the various DHIS discussion lists, because I think it has wider interest (estimating potential ANC clients accurately are a challenge for all countries, not only Nigeria). Explanation: If you draw a timeline from "conception" to "census taking of children under 1 year" (i.e. the children under 1 will on average be around 6 months during the census), it is a bit easier to determine the factor to multiply with the number of children under 1 year as per the census in order to estimate the number of "Potential ANC clients". Just note that we are making two assumptions: (1) All women who has been pregnant for 10 weeks or more should be aware that they are pregnant, and they should receive ANC care (in most countries, the policy is to encourage the first ANC visit in the first trimester, which is before 13 weeks). (2) We assumed that about 25% of all pregnancies end up with a spontaneous (or induced) abortion between 0-28 weeks gestation - that estimate was based on similar estimates from South Africa (abortion rates in wealthy countries are usually about half of that). AND we assumed that around 1/3 of those (~7-8%) occur between 10-28 weeks (i.e. those women have then become potential ANC clients BEFORE the pregnancy ends, for whatever reason). So you can set up the following timeline from "day 0" (conception) via 10 weeks (woman aware of pregnancy) and 28 weeks (normally viable foetus, i.e. 28 weeks divides spontaneous abortions from still births) and 38 weeks (delivery) to 6 months after delivery (average age for children under 1 year at time of census): Day 0: 1,000 women conceive 10 weeks: ~ 830 of them are still pregnant 28 weeks: ~ 750 of them are still pregnant 38 weeks: ~ 760 (10 twins) babies are born, with ~30 still born and 730 live born Neonatal period (0-28 days): Neonatal death rate is 53/1,000 live births, so ~40 die. 29 days - 6 months: infant mortality of ~22/1,000 live births, so another 15 die. 6 months after delivery: 675 are still alive to be counted in census Total infant mortality for Nigeria (Unicef, 2005) is 100/1,000 live born, but 53 of them die during the neonatal period and I estimate another 22 from 28 days to 6 months - which means that the last 25 will die between 6 months and 1 year. So the census figure that we are using as our basis will be 675. If you multiply that number with 1.23 (i.e. add 23%), you see that you arrive at ~830 - which is the estimated number of pregnant women who we regard as "potential ANC clients" (they SHOULD receive antenatal care). The various rates and assumptions are not 100% correct, of course - so anybody with better data/ideas are encouraged to revise them and improve the accuracy of the estimate. Hope this helps. Regards calle _______________________________________________ Dhis-users mailing list [email protected] http://www.hisp.info/mailman/listinfo/dhis-users
