Migrant suicide rates in Australia and in country of birth

Background. Various studies from Australia, Canada and the United States have shown significant rank correlations between the suicide rates of immigrants and those of their country of birth (COB). This study compares the rank ordering of age standardized suicide rates of immigrants in Australia for two periods, 1961-70 and 1979-90: (a) between each period; and (b) with their COB for each period. Methods. Data were obtained from the World Health Organization Annual Statistics and from the Australian Bureau of Statistics. Comparisons were made for 11 countries from England and Wales, Ireland and Europe, for which there was a sufficiently large number of immigrant suicides to warrant statistical analysis. Results. The data showed considerable heterogeneity in rates of immigrants from various countries, with increased rates in Australia compared with their COB. There were consistently significant Spearman rank correlations between the rates after immigration and those in their COB for each period, and between rates in the two periods for both immigrants and for their COB, despite increases in suicide rates, and considerable socio-economic demographic changes between the various countries over that time span. Conclusions. The findings are used to argue two conclusions: (i) the important influence of pre-migrant social and cultural experiences in subsequent suicide rates in immigrants in their host country; and (ii) to support the case for the reliability of using international suicide data for comparative epidemiological research.