One-week recall period gives a more accurate estimate of exclusive breastfeeding practice than 24-h recall among infants younger than six months of age

Background The World Health Organization recommends a 24-h recall period to estimate breastfeeding practice of mothers of infants aged younger than six-months. Though 24-h recall was preferred for its low recall bias and for practical reasons, it can overestimate exclusive breastfeeding practice (EBF). Validating this indicator will help account for the deviation from the true estimate. This prospective cohort study measured accuracy of the 24-h recall method and validates a week recall as an alternative approach for use in a small sample population. Method The study was conducted from March to April 2018 involving 408 mother-infant pairs living in Butajira Health and Demographic Surveillance Site (HDSS), Southern Ethiopia. Participants were prospectively followed for 14 consecutive days; where their breastfeeding practice in the past 24 h was measured daily. Exclusive breastfeeding prevalence estimate obtained using the 24-h recall method and recall periods spanning a varying number of days (short period recalls) was compared against the cumulative of the responses from a prospectively measured repeated 24-h recalls over the course of 14 days. McNemar statistics was used to assess statistical significance of the difference in the EBF prevalence estimates of the single 24-h recall and the reference standard. Sensitivity, specificity, positive predictive value and negative predictive values were calculated to determine the level of accuracy. Receiver Operating Characteristics curve was used to measure the difference in performance between the two methods. Result The highest prevalence (71.4%) of exclusive breastfeeding practice was estimated using the single 24-h recall method whereas the lowest breastfeeding practice (47.1%) was obtained from a cumulative of 14 repeated 24-h recalls. A week recall (a recall over 7 days' period), resulted in the smallest discrepancy in estimate (7.1%) as compared to cumulative estimate of 14 repeated 24-h recalls. Comparing against our reference standard, a week recall had 96.7% sensitivity and 83.5% specificity in estimating exclusive breastfeeding practice. Conclusions Using single 24-h recall method overestimated exclusive breastfeeding prevalence. However, a week recall gave an estimate close to the estimate from the standard method. A week recall has a potential to balance the tradeoff between the accuracy of EBF estimates and the resource implication of using multiple prospective measurements that have a proven superior accuracy.