The economics of child and adolescent health in Australia

The economics of child and adolescent health in Australia

Long-term medical conditions or disabilities, such as respiratory and allergic diseases, and obesity are the leading chronic conditions that affect children worldwide. This thesis examines the associations between maternal health and different childhood health outcomes, including wheezing, asthma, eczema and long-term medical conditions or disabilities. This thesis also identifies vulnerable clusters based on childhood wheezing, asthma or eczema morbidities and on the lifestyles and health behaviours of adolescents that contribute to obesity. Finally, this thesis examines the excess healthcare costs that are associated with children’s asthma and any medical condition or disability that lasts six months or more. To accomplish the research objectives and make new contributions to the literature, this ‘PhD by publication’ thesis presents an accumulation of eight studies that use data from the Longitudinal Study of Australian Children (LSAC). The adapted developmental origins framework and the bio-ecological model of child development underpin this thesis, and the research relies on the applied quantitative approach for the empirical analyses. The spectrum of the study was enhanced by establishing data linkages between the Health CheckPoint survey, the Pharmaceutical Benefits Scheme and the Medicare Benefits Schedule data with the LSAC databases. The thesis follows a typical format: the eight research articles are bookended by rudimentary introduction and conclusion chapters. The research contents of this thesis are divided into the following four main parts:

i) prevalence and risk factor analyses of children’s health
a. in general
b. based on leading chronic diseases – wheezing, asthma and eczema (Papers 1 and 2)
ii) survival analyses and risk factor assessments for long-term medical conditions or disabilities (Papers 3 and 4)
iii) identification of clusters of vulnerable children in relation to respiratory and allergic diseases and health-related behaviour or lifestyle characteristics (Papers 5 and 6)
iv) cost studies that assess the excess healthcare cost of children that are associated with asthma and long-term health conditions or disabilities (Papers 7 and 8)

Paper 1 utilised a cross-section analysis of infants’ and adolescents’ health status through the lens of the foetal origins hypothesis and analyses data from Wave 1 and Wave 7 of the LSAC surveys. The study found evidence that poor maternal physical health status and health-related behaviours during pregnancy or up to 15 months from childbirth adversely affected their children’s health during infancy and adolescence in all three of the health dimensions examined; the poor general health, the chronic health conditions and lower physical health scores. Maternal psychological distress during pregnancy also increased the odds that their offspring would develop chronic health conditions and have lower physical health scores. Focusing again on the foetal origins framework and further strengthened by using longitudinal data from eight waves, Paper 2 reveals that maternal asthma, obesity, and smoking during pregnancy are strongly associated with an increased risk of offspring’s wheezing and asthma. This study also reveals that the risk of contracting childhood eczema is mainly associated with maternal asthma during pregnancy. Paper 3 deployed a panel data survival analysis method to estimate the prevalence of long-term medical conditions or disabilities in Australian children. This study also examined the association of maternal healthrelated risk factors with chronic health conditions. Through an application of the same technique (survival analysis), Paper 4 reveals that low birth weight, receiving emergency hospital services just after birth, being male and being obese during childhood up to the age of 15 years are associated with an increased risk of having a long-term medical condition or disability. Both Papers 3 and 4 deployed a ‘developmental origins’ framework in forming the study questions and interpreting the findings. iii This thesis implemented an unsupervised machine learning method known as latent class clustering to identify the vulnerable clusters of children who experience wheezing, asthma or eczema and vulnerable children with problematic lifestyles and health behaviours who are prone to be obese and have a lower quality of life (Paper 5 and 6, respectively). Finally, Papers 7 and 8 were conducted using a health economic approach to assess the direct costs of healthcare services. Paper 7 utilised an assessment of the national-level excess healthcare costs for Australian children that are associated with the burden of asthma morbidity. The estimated increased costs to the Australian healthcare system due to childhood asthma are A$190.6 million per year among children ages 2-3– to-18-19, based on the 2018 population data. Paper 8 reveals that at the population level, the estimated total excess Medicare costs associated with a medical condition or disability among children ages 0-1-to–16-17 is, on average, A$170.0 million per year. The evidence from this thesis should help health policymakers find ways to reduce and control asthma, obesity and long-term health conditions or disabilities and gain further insight into the associated excess healthcare costs of asthma and any childhood medical condition or disability.

This article is part of a UniSQ Thesis by publication. See Related Output