Epidemiological transition in Australia: An analysis of immigration patterns in relation to circulatory system diseases and all-cause mortality in the mid-twentieth century

Background and Objectives Circulatory System Diseases (CSD) patterns vary over time and between countries, related to lifestyle risk factors, associated in turn with socio-economic circumstances. Current global CSD epidemics in developing economies are similar in scale to those observed previously in the USA and Australasia. Australia exhibits an important macroeconomic phenomenon as a rapidly transitioning economy with high immigration throughout the 19th and 20th centuries. We wished to examine how that historical immigration related to CSD patterns subsequently. Methods and Setting We provide a novel empirical analysis employing census-derived place of birth by age bracket and sex from 1891 to 1986, in order to map patterns of immigration against CSD mortality rates from 1907 onwards. Age-specific generalised additive models for both CSD mortality in the general population, and all-cause mortality for the foreign-born (FB) only, from 1910 to 1980 were also devised for both males and females. Results The % FB fell from 32% in 1891 to 9.8% in 1947. Rates of CSD rose consistently, particularly from the 1940s onwards, peaked in the 1960s, then declined sharply in the 1980s and showed a strong period effect across age groups and genders. The main effects of age and census year and their interaction were highly statistically significant for CSD mortality for males (p < 0.001, each term) and for females (p < 0.001, each term). The main effect of age was statistically significant for all-cause mortality minus net migration rates for the FB males (p =0.005) and for FB females, both age (p < 0.001) and the interaction term (p=0.002) were significant. Conclusions We argue our empirical calculations, supported by historical and socio-epidemiological evidence, employing immigration patterns as a proxy for epidemiological transition, affirm the lifecourse hypothesis that both early life circumstances and later life lifestyle drive CSD patterns. Strengths Limitations ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any specific funding. Professor Cecily Kelleher undertook the research in Australia on which this paper is based with funding from a Miegunyah Fellowship at the University of Melbourne. Dr Jonathan Briody was funded by the Health Research Board SPHERE PhD training programme. Professor Janet McCalman is supported by the ARC, Australian Research Council. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Source data were openly available before initiation of the study. 1.Australian Bureau of Statistics. http://www.abs.gov.au/AUSSTATS/abs@.nsf/ViewContent?readform&view=ProductsbyCatalogue&Action=Expand&Num=2.2 accessed 12th January 2019 2.Australian Institute of Health and Welfare. https://www.aihw.gov.au/reports-data/health-conditions-disability-deaths/heart-stroke-vascular-diseases/overview, accessed 12th January 2019. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors