Are health inequalities increasing with time? Results of a literature review and recommendations for further research

Abstract

It has been shown that socio-economic status (SES) and health are closely linked to one another. Now we focus on further questions, and one of the most important ones is whether these "health inequalities" increase with time. In Germany, there is little discussion about this question and no review summarising the empirical evidence is available.This review focuses on 4 dimensions: time trends of health inequalities concerning mortality (or, respectively, life expectancy), self-rated health, smoking and obesity. First we included all empirical analyses from Germany, and all analyses from other European countries published between 2008 and 2012. Then, step-wise, 44 studies (including 5 from Germany) were selected by predefined criteria for a detailed -description of empirical results and methods.The number of publications has strong-ly increased in recent years, illustrating the growing interest in time trends of health inequalities. The empirical results of the 44 studies could be summarised in the following way: All in all, 184 empirical results are reported about time trends in health inequalities and 112 of them show increasing inequalities; decreasing inequalities are shown in 13 reports. The studies from Germany point in the same direction (i. e., most results indicate increasing health inequalities). It is also important to stress that there is great -heterogeneity concerning the methodical approaches. Some studies analyse health inequalities by individual socio-economic status (e. g., educational level), others by regional deprivation. Sometimes changes in the extent of health inequalities over time are not calculated explicitly. Some papers do not include absolute and relative measures of inequalities, but just one of them.In Germany, there is a need for more empirical studies looking at time trends of health inequalities; the available datasets should be used more often for this type of analysis. If possible, further studies should include individual SES and regional deprivation, measures of absolute and relative inequality (stratified by sex, with significance tests for time trend), and they should cover as many points in time as possible. Also, it would be important to relate the chang-es in health inequalities to the other changes in the society.