CALCASEID_CMC is a 20-digit variable with no implied decimal places. The variable joins the value of CASEID, the case identification string from the women's (IR) source file for a sample, followed by a "_" and then the date of the woman-month as a century-month value. Cases requiring fewer than 20 digits are padded with leading zeroes. See the variable description for more information on this variable.
Description
CALCASEID_CMC is a unique (within sample) woman-month identifier. This variable is meaningful only within a given sample and cannot be used to track a woman across DHS samples from multiple years for a country.
The first element of CALCASEID_CMC repeats the value of CASEID, the original case identification string from the women's (IR) source file for a sample. As a unique identifier for each woman in a given sample, CASEID is generally created by The DHS Program from three variables: CLUSTERNO (V001), HHNUM (V002), and LINENO (V003), with the last three characters indicating the female respondent's line number in the household file.
The second element of CALCASEID_CMC reports the date of the woman-month as a century month value. CALCASEID_CMC concatenates CASEID and CALCMC_MONTH, separated by a "_".
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 DHS-relevant events occurred during the twentieth or twenty-first century. The month of the event is added to the previous result.
For example, the CMC for June 2002 is:
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:
For more information, visit The DHS Program website to find the latest Guide to DHS Statistics.
Comparability
Apart from universe differences, CALCASEID_CMC is consistent across samples, but it has meaning only within a given sample.
Comparability - Standard DHS
CALCASEID_CMC is a technical variable created by IPUMS DHS staff during the processing of calendar string data from the women's (IR) files.
