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

Abstract

AbstractBackground and ObjectivesCirculatory 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 19thand 20thcenturies. We wished to examine how that historical immigration related to CSD patterns subsequently.Methods and SettingWe 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.ResultsThe % 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.ConclusionsWe 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.Article SummaryStrengthsAn original analysis employing census data and immigration patterns to reinterpret historical trends in CSD in AustraliaRelevant to modern public health policy for population approaches to CSD prevention, also integrates lifecourse and lifestyle drivers of trendsLimitationsHistorical databases do not categorise either all cause or CSD mortality according to country of origin.However, data for foreign-born mortality were inferred using novel actuarial type calculationsThere are no second-generation data by country of origin, unlike in USA.