Breastfeeding is a complex behaviour relying on a combination of individual mother and infant characteristics, health systems, and family, community and professional support. Optimal breastfeeding in high-income countries is particularly low. Despite having similar sociocultural backgrounds, breastfeeding rates between Ireland, the United Kingdom (UK) and Australia vary, thus there is a need to understand whether this is due to individual, sociocultural or policy differences. This research identifies the between-country differences in infant feeding mode and examines if country differences in feeding mode persist once known individual, behavioural and structural factors are considered using socioecological and person-context models. Participants were adult women with at least one infant less than 6 months of age, who completed an online survey (n = 2047) that was distributed by social media in June 2016. Within-country differences in infant feeding mode (‘any breastfeeding’ vs. ‘no breastfeeding’) were examined first before hierarchical multivariable logistic regression was used to determine if country differences in feeding mode persisted after adjusting for known factors associated with breastfeeding. In this sample, ‘any breastfeeding’ rates were 89, 71 and 72% in Australia, Ireland and the United Kingdom respectively. Within-country differences were evident in Australia, Ireland and the UK. Four factors showed no association with infant feeding mode in Australia while they did in the other countries (maternal age, income, skin-to-skin contact, support from friends and family). Two factors were unique to Australia: the odds of being in the ‘no breastfeeding’ group increased when the baby was delivered via caesarean and when not enough breastfeeding information was available after birth. One determinant was unique to Ireland: the odds of being in the ‘no breastfeeding’ group increased when respondents indicated they were not religious; in the UK this occurred when respondents were living in a town/village. After adjusting for sets of known factors of infant feeding mode based on socioecological and person-context models, country differences remained in hierarchical regressions: the odds of not breastfeeding were higher in both Ireland (AOR 3.3, 95%CI 1.8,6.1) and the United Kingdom (AOR 2.7, 95%CI 1.5, 4.7) compared to Australia. This study indicates that different levels in the socioecological system are related to infant feeding behaviours. An adequate inter-systems level response would consider the interactions within and between behavioural and structural mechanisms which support breastfeeding behaviour. Optimising infant feeding practices will require an integrated web of interventions that go beyond the individual and focus on addressing factors that will influence families within their communities as they move between systems.

中文翻译：

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了解母乳喂养行为：爱尔兰、英国和澳大利亚相关因素的横断面分析

母乳喂养是一种复杂的行为，它依赖于母婴个体特征、卫生系统以及家庭、社区和专业支持的综合作用。高收入国家的最佳母乳喂养率特别低。尽管有着相似的社会文化背景，爱尔兰、英国 (UK) 和澳大利亚之间的母乳喂养率有所不同，因此有必要了解这是否是由于个人、社会文化或政策差异造成的。这项研究确定了国家间婴儿喂养模式的差异，并检查了一旦使用社会生态和个人背景模型考虑了已知的个人、行为和结构因素，国家之间喂养模式的差异是否持续存在。参与者是至少有一名不到 6 个月大的婴儿的成年女性，谁完成了 2016 年 6 月通过社交媒体发布的在线调查（n = 2047）。在使用分层多变量逻辑回归之前，首先检查了国家内部婴儿喂养模式（“任何母乳喂养”与“非母乳喂养”）的差异确定在调整了与母乳喂养相关的已知因素后，各国喂养方式的差异是否仍然存在。在该样本中，澳大利亚、爱尔兰和英国的“任何母乳喂养”率分别为 89%、71% 和 72%。澳大利亚、爱尔兰和英国的国家内部差异很明显。四个因素与澳大利亚的婴儿喂养方式无关，而在其他国家（产妇年龄、收入、皮肤接触、朋友和家人的支持）。澳大利亚有两个独特的因素：当婴儿通过剖腹产分娩以及出生后没有足够的母乳喂养信息时，“不母乳喂养”组的几率会增加。爱尔兰独有的一个决定因素是：当受访者表示他们不信教时，属于“不母乳喂养”组的几率就会增加；在英国，当受访者住在城镇/村庄时，就会发生这种情况。在根据社会生态和个人背景模型调整婴儿喂养模式的一组已知因素后，国家差异仍然存在于分层回归中：爱尔兰 (AOR 3.3, 95%CI 1.8,6.1) 和与澳大利亚相比，英国 (AOR 2.7, 95% CI 1.5, 4.7)。本研究表明，社会生态系统的不同层次与婴儿喂养行为有关。一个适当的系统间层面的反应将考虑支持母乳喂养行为的行为和结构机制内部和之间的相互作用。优化婴儿喂养做法将需要一个综合干预网络，该网络超越个人，侧重于解决影响社区内家庭在系统之间移动时的因素。