High adherence and its influencing factors on multiple micronutrient powders (MNPs)

Adherence to home fortification of foods with multiple micronutrient powders (MNPs) is an essential indicator of effective implementation of MNP programmes. A meta-analysis was conducted to evaluate the high adherence rate (HAR) to MNPs and further investigate the factors that influence HAR. We searched PubMed, Web of Science, Embase, CAB Abstracts, MEDLINE (OVID), Cochrane Library, China National Knowledge Infrastructure, Wanfang and VP, from the date of database inception to 9 November 2020. We included peer-reviewed observational studies that investigated adherence to MNPs. Data on the HAR to MNPs and influencing factors on HAR were extracted and then pooled together. A total of 10 studies were included. The pooled HAR to MNPs was 63.28% (51.12%-74.64%). Among HARs, rates were higher in middle-income countries (65.21%) than low-income countries (55.23%). Parental age over 30 years (maternal age OR = 1.25, 95% CI: 1.08-1.44; paternal age OR = 1.17, 95% CI: 1.04-1.32), children aged 18-36 months (OR = 1.45, 95% CI: 1.12-1.88), maternal educational attainment of college or above (OR = 1.38, 95% CI:1.10-1.73), caregiver with the perception that other mothers use MNPs (OR = 1.52, 95% CI:1.19-1.95), caregiver being aware of the importance of iron (OR = 1.42, 95% CI: 1.18-1.71), caregiver having correct knowledge of MNPs (OR = 1.36, 95% CI:1.19-1.57) and caregiver reporting children have no side effects from MNPs (OR = 2.77, 95% CI: 2.46-3.11) were contributing factors to high adherence to MNPs. The overall HAR to MNPs was relatively low; hence, effective and trusted communication channels need to be established, along with more thorough dissemination of the knowledge of MNPs to caregivers, to improve MNPs adherence rates, especially in low-income countries.