Study measures

Information on compliance with the recommended calcium consumption regimen was captured in two ways. First, FCHVs conducted a tablet count at the end of pregnancy as part of routine monitoring. Second, we collected information on self-reported compliance in the household survey. The household survey also gathered information on correct dose, timing and frequency and duration of calcium consumption. Self-reporting is the international standard for measuring iron coverage and consumption through the DHS and the Multi-Indicator Cluster Survey (MICS) international household survey programs and thus it was the key method used in this study to measure calcium coverage and consumption during pregnancy.

Self-reported duration of calcium consumption also was measured. The number of days calcium was consumed was divided into three categories: a full course (150 days or 300 tablets), a partial course (90–149 days or 180–298 tablets), and short course (fewer than 90 days or less than 180 tablets). The number of days was determined using the responses from postpartum women who consumed calcium during their last pregnancy by asking, “How many days did you take calcium tablets during your last pregnancy?”