Assessment of child feeding practices using a summary index:: stability over time and association with child growth in urban Madagascar

Background: Previous studies investigating the association between an infant and child feeding index (ICFI) and length-for-age were based on a cross-sectional design and on the assumption that data collected with brief recalls could provide information about more enduring processes. Objectives: The objectives were to test the stability of the individual ICFI values over time and to investigate how they relate to length-for-age z score (LAZ) and weight-for-length z score (WLZ) at the end of the study. Design: This prospective cohort study included 363 children aged 6-17 mo who were visited 3 times over 6 mo. A cross-sectional ICFI (CS-ICFI) was constructed for each visit by using data on feeding practices and data from quantitative 24-h recalls. A longitudinal ICFI (L-ICFI) was constructed with use of the 3 CS-ICFIs. The stability of the CS-ICFI was assessed by using the variance of the repeatability coefficient (s(2)r). Results: Stability of the CS-ICFI was shown by the value of 0.704 (95% CI: 0.625, 0.805) of the s(2)r, which differed significantly from 1 (P G 0.0001). There was no significant association between the CS-ICFIs and LAZ or WLZ at visit 3. In contrast, when moving from low to high L-ICFI, there was a highly significant 0.5 z score difference in mean LAZ at visit 3 (P = 0.0008). The L-ICFI was not associated with WLZ. Conclusions: The ICFI constructed by using data collected with brief recalls can provide information about feeding in the long term. However, the absence of association with LAZ suggests a lack of precision that can be reduced by using an ICFI based on repeated measurements.