(P26-025-23) An Alternative Growth Metric To Assess the Effect of Small-Quantity Lipid-Based Nutrient Supplements on Child Linear Growth in Low- and Middle-Income Countries (LMICs)

Objectives: To compare the use of ‘height-age’ (HA) as an alternative to length-for-age z-scores (LAZ) to assess the effect of small-quantity lipid-based nutrient supplements (SQ-LNS) on children’s linear growth in low- and middle-income countries (LMICs).

Methods: Previously-published results from a meta-analysis of randomized controlled trials of SQ-LNS on child linear growth were re-expressed as HA. An updated literature search was conducted for inclusion of relevant trials published up to September 27, 2022. Pooled analyses were conducted using an inverse variance fixed effect model. Effects of SQ-LNS versus control were expressed using LAZ and HA; HA was further used to calculate the novel ‘proportion of maximal benefit’ (PMB) metric, where a PMB of 0% represents that SQ-LNS led to no improvement in linear growth compared to the control, and 100% that SQ-LNS achieved the intervention group’s optimal growth potential for their baseline stage of skeletal maturation and the intervention duration. Between-study heterogeneity was assessed using the I² statistic.

Results: In total, 18 comparisons (SQ-LNS versus control group) from 15 trials conducted in 10 LMICs were included. At an average end-line age of 570 days (18.7 months), the pooled mean difference in LAZ and HA in the SQ-LNS group versus control was 0.15 (95% CI: [0.13, 0.17]; I²: 46%) and 12 days (95% CI: [9.6, 13.6]; I²: 59%), respectively (N=36970 participants (18 comparisons)). Corresponding LAZ and HA estimates were highly correlated (Spearman rho = 0.94; p< 0.001) after exclusion of one extreme outlier. The pooled PMB achieved by SQ-LNS was 11% (95% CI: [9.0, 12]; I²: 89%; N=19946 participants (13 comparisons)).

Conclusions: Re-expression of the effect of SQ-LNS on child linear growth in terms of HA, rather than LAZ, provides new information about the extent to which SQ-LNS optimizes growth and the observed heterogeneity of this benefit across different trials.

Funding Sources: This work is funded by the Canadian Institutes of Health Research (CIHR), through the Canadian Graduate Scholarship – Masters (CGS-M) and a project grant. The CIHR had no involvement in this study, and does not restrict works for publication.