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Defining breastfeeding in epidemiology studies

Colin Binns¹, Mi Kyung Lee², Andy Lee¹

¹School of Public Health and Curtin Health Innovation Research Institute, Curtin University

²Faculty of Health Sciences, Murdoch University

Exclusive breastfeeding for the first 6 months of life is recommended as the optimal way to feed infants.  While there is general agreement on the definitions of breastfeeding, there is considerable differences in the way they are operationalized.  This paper reviews the measurement of exclusive breastfeeding in Australia and China over the past decade. Only half the studies identified that claimed to measure exclusive breastfeeding used a definition consistent with the World Health Organisation. Three studies used 24-h or 7-day recall indicators that have been shown to produce overestimations of the prevalence of exclusive breastfeeding. 

In China our studies have shown that rates of prelacteal feeds range from 24-83% and these are often ignored in establishing exclusive breastfeeding rates. Epidemiology studies often rely on recall several months or years after the breastfeeding exposure.  This leads to errors in misclassification of exclusive breastfeeding.  The measurement of exclusive breastfeeding is important because of emerging evidence on the importance of the human microbiome on health.  Correct definition of exclusive breastfeeding is particularly important in studies related to allergy, asthma and obesity.

 Measurement of exclusive breastfeeding with a valid and consistent definition is vital for monitoring rates and trends, for comparison between different studies and countries and to reach accurate conclusions on health benefits. Any future measurement of exclusive breastfeeding in epidemiology should use the World Health Organisation definition and should preferably use a prospective cohort design.

263 words