Statistical Approaches in the Studies Assessing Associations between Human Milk Immune Composition and Allergic Diseases: A Scoping Review

Abstract

A growing number of studies are focusing on the associations between human milk (HM) immunological composition and allergic diseases. This scoping review aims to identify statistical methods applied in the field and highlight pitfalls and unmet needs. A comprehensive literature search in MEDLINE and Embase retrieved 13,607 unique records. Following title/abstract screening, 29 studies met the selection criteria and were included in this review. We found that definitions of colostrum and mature milk varied across the studies. A total of 17 out of 29 (59%) studies collected samples longitudinally, but only 12% of these used serial (longitudinal) analyses. Multivariable analysis was used in 45% of the studies, but statistical approaches to modelling varied largely across the studies. Types of variables included as potential confounding factors differed considerably between models. Discrimination analysis was absent from all studies and only a single study reported classification measures. Outcomes of this scoping review highlight lack of standardization, both in data collection and handling, which remains one of the main challenges in the field. Improved standardization could be obtained by a consensus group of researchers and clinicians that could recommend appropriate methods to be applied in future prospective studies, as well as already existing datasets.

Non-Coding RNAs in Human Breast Milk: A Systematic Review

“…Heterogeneity, lack of standardisation of sample collection and processing within and between studies is a common challenge in breast milk research (64)(65)(66). The studies included in this review were no exception and, like others before us, we identified a need for greater standardisation and clearer reporting of sample collection and processing methods (64,66).…”

“…This is a common feature for young and fast-growing research fields as the coherence in methods and other study features are continually developing. Furthermore, heterogeneity, lack of standardisation of sample collection and processing within and between studies is a known challenge in breast milk research (64)(65)(66). The studies included in this review were no exception and, like others before us, we identified a need for greater standardisation and clearer reporting of sample collection and processing methods which we discuss below (64,66).…”

Diversity and trends of human milk banking: a scoping review from 1946 to 2021

“…As interest in DHM use and human milk science increases,12 more research is undoubtedly warranted to unravel potentially underlying mechanisms, the complex characteristics of DHM and its potential health effects 13. While systematic reviews are used to discover and identify, analyse and synthesise already existing evidence relevant to a certain research topic and question,14 scoping reviews have become particularly useful when a topic is underinvestigated as a more prominent method of summarising research information 15.…”