Non-random geographical distribution of infant mortality in Austria 1984–2002

Abstract

Over the last 20 years in Austria infant mortality has declined from 11.2/1,000 life births (1985) to 4.7/100,000 (1997) but has remained constant since then. This stagnation is in contrast to the trend in Finland, where the infant mortality rate is both lower than in Austria and continues to decline. In attempting to understand this difference we concentrated on the spatial distribution of infant mortality in Austria in addition to the trend over time. We describe the regional distribution of infant mortality adjusted by risk factors over the period from 1984 to 2002 based on data from 1.6 million birth certificates. All variables we examined were significant due to the large number of observations. We calculated an R-squared measure to assess the ability of our regression model to predict the survival status of newborns. Only the variables birth weight, gestational age, infant's length at birth and to a lesser extent year of birth had relevant impacts in terms of predictive ability. All remaining variables did not notably contribute to the prediction of survival status of the newborn despite their significance. In the greater area of Styria, infant mortality is significantly lower than in the rest of Austria even when the mortality rates are adjusted for variables such as birth weight, gestational age, sex of the newborn and sociodemographic status of the mother. In the period from 1984 to 2002 about 1500 more infants would have survived the first year of life if the mortality rate in the rest of Austria had been the same as in this area. In our regression model many important risk factors were included. Nevertheless, we can not explain the observed spatial pattern in infant morality. Further analytic studies are needed to explore the impact of variables other than those contained in the birth certificates.

Analysis of the spatial distribution of infant mortality by cause of death in Austria in 1984 to 2006

“…Infant mortality rate in Austria was higher than average in the European Union until 1987 but now has reached the European Union means [ 1 , 2 ] (Figure 1 ). Despite this very welcome temporal trend, in a recent study [ 3 ] including the years 1984–2002, we observed an explicit non-uniform spatial distribution indicating lower risks in the South-East of Austria. This study was based on about 1.6 million individual birth certificates allowing the adjustment of the infant mortality rates for a large number of covariates.…”

“…In a recent paper [ 3 ] we were able to show that in the last 2 decades infant mortality was not randomly spatially distributed in Austria. In this present study including four additional years we were able to show that the spatial distribution of mortality within first year of life depends on the cause of death.…”

“…As the focus of this study is the description of the six group-specific spatial distributions, the results of the logistic regression models are not shown. For a detailed description of the effects of the covariates on overall infant mortality we refer to Waldhoer, et al, 2006 [ 3 ].…”

Relevance of the type III error in epidemiological maps

“…In Austria infant mortality dropped sharply from about 25.9 ‰ in 1970 to 11.2 ‰ in 1985 and 3.9 ‰ in 2010 [9,10]. Apart from the temporal trend, a clear non-random spatial distribution was observed from 1984 to 2002 [11]. In a regression model based on individual data, infant mortality in the south-eastern province of Styria was markedly lower than that in the rest of Austria even after adjusting for strong predictors like gestational age and sex.…”

Politische Kindermedizin im internationalen Vergleich

“…Im Herbst 2003 haben 12 größtenteils langgediente Kinderärzte und Kindertherapeuten mit dem an die breite Öffentlichkeit gerichteten Sachbuch "Weggelegt -Kinder ohne Medizin?" auf diese Defizite hingewiesen [37]. Konkrete Beispiele aus der sozialpädi-atrischen Unterversorgung und Defizite im tertiären Versorgungssektor wurden aufgezeigt und konkrete Verbesserungen eingefordert [19].…”