DOBCMC is a 4-digit variable that represents the century-month value (months since 1900) of the woman's birthdate. The following values represent NIU (not in universe) or missing cases:
9995 = Not interviewed (female questionnaire)
9996 = Not interviewed (household questionnaire)
9998 = No response or missing
9999 = NIU (not in universe)
DOBCMC reports the century month code (CMC) for the month and year of the woman's birthdate.
Note that January is consistently the most common month across samples (see BIRTHMO). Due to the data entry format of the survey, if a respondent reported a year but not a month for her birthdate, January was the default month. Also due to the data entry format, if a woman skipped the question, the default date was January 1st, 2021. IPUMS has recoded these latter cases to "No response."
Century month codes (CMC) are particularly useful for checking the consistency of dates, calculating intervals between events, and imputing dates when the information for an event is missing or partially complete.
Century month codes (CMC) are calculated by multiplying by 12 the difference between the year of an event and 1900. The year 1900 was chosen as the reference period because all of the relevant events for PMA2020 occurred during the twentieth or twenty-first centuries. The month of the event is added to the previous result, in the following formula:
CMC = (Year - 1900) * 12 + Month
For example, the CMC for June 2002 is:
CMC = (2002 - 1900) * 12 + 6 = 1230
In other words, 1,230 months have elapsed between January 1900 and June 2002. Starting with CMC figures, one can calculate the month and year using the following formulas:
Year = int( ( CMC - 1 )/12 ) + 1900
[int(x) is the integer part of x]
Month = CMC - ( ( Year - 1900 ) * 12 )
The information above is based on "Online Guide to DHS Statistics" (Rutstein and Rojas, 2006).
The question associated with this variable was included in the female questionnaire.
- Women aged 15-49.
- Burkina Faso: 2014-2016
- Congo (Democratic Republic): 2014-2016
- Cote d'Ivoire: 2017
- Ethiopia: 2014-2017
- Ghana: 2014-2016
- India: 2016-2017
- Indonesia: 2015-2016
- Kenya: 2014-2016
- Niger: 2015-2017
- Nigeria: 2014-2017
- Uganda: 2014-2017