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Re: Stillbirth calculation for Philippines [message #26337 is a reply to message #26330] |
Wed, 08 March 2023 16:44 |
Janet-DHS
Messages: 847 Registered: April 2022
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Senior Member |
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Please refer to Tom Pullum if you have any other questions he is the one responding to your questions.
Following is a response from DHS staff member, Tom Pullum:
In the Zambia 2018 survey, the only information about stillbirths seems to be in vcal_1. This covers the interval from the start of the calendar (see the questionnaire for that) to the month of interview. The interval can be more than 60 months. The strings that indicate a stillbirth can be left-censored, that is, some of the months of pregnancy may be before the first month of the calendar, so it may not be possible to determine the length of those pregnancies.
The Stata lines below will identify whether the woman had a stillbirth, to the extent that it can be determined. The crucial command is "regexm", one of Stata's "string" commands. It produces a variable that is either 0 or 1.
* Identify stillbirths in the calendar, using the Zambia 2018 DHS survey.
* In this survey, miscarriages, abortions, and stillbirths are not given separate codes.
* Pregnancies that did not end in a live birth have code "T" in the monthe of termination.
* Stillbirths are T preceded by 6+ months with P. The calendars is in vcal_1.
use "..ZMIR71FL.DTA" , clear
gen had_stillbirth=regexm(vcal_1,"TPPPPPP")
label define noyes 0 "No" 1 "Yes"
label values had_stillbirth noyes
tab had_stillbirth
list vcal_1 if had_stillbirth==1, table clean
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Re: Stillbirth calculation for Philippines [message #26395 is a reply to message #26362] |
Wed, 15 March 2023 14:03 |
Janet-DHS
Messages: 847 Registered: April 2022
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Senior Member |
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Following is a response from DHS staff member, Tom Pullum:
A note to other forum users--the question is now about Zambia even though the subject line says "Philippines".
Without going into the file myself, I can speculate that there are two possible reasons for the difference. The first is that the number of stillbirths in the report will be weighted (by v005). If your number is unweighted, it will differ. A second reason is that the code I gave is for all months in the calendar, not just the 60 months before the month of interview. You can reduce vcal_1 to just the 60 months before the interview, and that will give a smaller number. You should be able to reduce vcal_1 to just the last 60 months, with the name "vcal", with this line: "gen vcal=substr(vcal_1,v018,60)".
I hope you can get close to a match if you reduce vcal_1 to vcal and count the weighted number of stillbirths, but there may still be some discrepancy because of pregnancies of indeterminate length at the beginning (the right end) of the calendar.
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Re: Stillbirth calculation for Philippines [message #26544 is a reply to message #26516] |
Thu, 30 March 2023 15:51 |
Janet-DHS
Messages: 847 Registered: April 2022
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Senior Member |
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Following is a response from DHS staff member, Tom Pullum:
Again, this post is about a survey in Zambia rather the Philippines.
The following Stata lines count up the number of strings of the two types--B or T preceded by 6 or more P's. I do not include ambiguous strings that overlap the beginning of the calendar. The number of pregnancies you are looking for will be the sum of these two types.
use "...ZMIR71FL.DTA", clear
* for each woman, count up the number of strings of TPPPPPP or BPPPPPP in vcal_1
gen nT=0
gen nB=0
gen str7 compare="."
quietly forvalues lcol=1/74 {
replace compare=substr(vcal_1,`lcol',7)
replace nT=nT+regexm(compare,"TPPPPPP")
replace nB=nB+regexm(compare,"BPPPPPP")
}
drop compare
tab nB nT
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