320) FOR EACH BIRTH SINCE JANUARY 1985 ENTER "B" IN MONTH OF BIRTH IN COLUMN 1 OF CALENDAR AND "P" IN EACH OF THE 8 PRECEDING MONTHS.
Categories
Value
Category
998
Missing
999
NIU (not in universe)
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.
concept
Concept
var_concept.title
Vocabulary
General maternal and infant health Variables -- TOPICS