Socio-economic inequalities in health are a major challenge for public health. It has been long observed that health, morbidity, disability and mortality are socially patterned. Several epidemiological studies consistently show that individuals of lower socio-economic status have poorer health status, higher mortality rate, riskier lifestyle and poorer preventive behaviour. Such differences, often called socio-economic inequalities in health (SIH), have been observed in most European countries (Mackenbach, 2004). Belgium is no exception. Recent research has identified inequalities in mortality (Deboosere, 2002; Lorant, 2001), in morbidity and disability free life expectancy (Bossuyt, 2004), in mental health (Lorant, 2002) and in health care (Van der Heyden, 2003). Health-related behaviours have been found to contribute to socio-economic inequalities in mortality and morbidity.
Reducing inequalities in harmful lifestyles such as smoking, drinking and overweight and in health enhancing lifestyles such as physical activity are essential in any overall strategy to reduce inequalities in health. However, health promotion policies and interventions to reduce harmful behaviours often may reinforce and widen rather than reduce the health divide because of differential access and use between social groups. Further, the importance of individual factors is uncertain, as this is likely to vary between genders and it is strongly influenced by change over time. Most studies evaluating the selection and the causation hypotheses of social inequality in health favour the latter but are often limited because of the use of invariant social classification (education). Recent reviews of contextual factors have broadened the perspective beyond social disadvantage and identified five types of contextual features on health: physical features such as the quality of air and water; public services to support individuals in their daily lives; decent housing; socio-cultural features and, finally, the reputation of the area (Macintyre, 2002).
The project therefore focuses on the understanding of the determinants of health inequalities in order to strengthen the basis to develop systematic and comprehensive policy strategies to tackle health inequalities. The overall aim of the project is (1) to describe the size and the time trend in social inequalities in health and in harmful and health enhancing behaviours; (2) to analyse the impact on the social inequalities in health of individual factors (social inequalities in lifestyles (SIL), occupational exposures, family structure) and macro-social factors (social capital, urbanisation of living environment).
Objective 1: Description of the social inequalities in health, mortality and disability free life expectancy (DFLE) and the evaluation of differential compression/expansion of the DFLE by social position over time in the period 1996-2001. More specifically the aim is to study:
* the effect of the social position on mortality, on subjective health, on chronic morbidity and on activity restrictions
* if the impact of life styles on mortality is differential by social position
* the size of the socio-economic gap in life expectancy and disability free life expectancy
* the evolution over time of the disability free life expectancy by socio-economic position
Objective 2: Analysis of social inequalities in health in relation to the longitudinal changes in social position between 1991 and 2001 through the follow-up of the census 1991 population and to study the longitudinal effect of the (changing) social position on health and lifestyles.
Objective 3: Study the effect of macro-factors on the social inequality in health and mortality
Objective 4: Evaluation of the time trend in the association of the social inequality in health and the social inequality in lifestyles.
The study will use existing data:
* Census 1991 and 2001;
* Panel Household Surveys 1992-2002;
* National mortality database: census data by 5 year mortality follow-up;
* Health Interview Survey (HIS): 1997, 2001, 2004;
* Mortality HIS (1997, 2001 with follow-up up to 2006).
The research proposal will help policy makers and steak holders in developing and evaluating policy instruments to reduce social inequalities in health, as e.g.:
* The project will describe the size of the social inequalities in health and in health related behaviours. It will describe the evolution of these inequalities over time and provide information on the relation between the evolution of inequalities in life styles and social inequalities in health.
* Through the analytic approach the project will identify mechanisms with a direct and intermediary impact on the social inequalities in health. The project especially focuses on the effect of the social inequalities in lifestyles on the social inequalities in health.
* The use of longitudinal data and the estimation of time trends makes it possible to identify strategies which may have an impact on the social inequalities. The project especially focuses on the observation that tackling health harming behaviours or promotion health enhancing behaviours may consolidate or even widen the health gap between social groups.
* The Belgian population is aging and the life expectancy continues to increase. But this increase in the number of years may be different by social group. Further, the division of these years gained into years in good or bad health may be different. Because the life expectancy and disability free life expectancy are expressed in years, the results of the time trend are easy to understand by policy makers. Evidence of a divergent evolution will put health inequalities high on the agenda.
* Bossuyt, N, Van Oyen, H. Health expectancy by socio-economic gradient in Belgium (Gezondheidsverwachting volgens socio-economisch gradiënt in België). (108), 1-86. 2001. Brussels, National Institute of Statistics. Statistical Studies (Statistische Studiën).
* Bossuyt N, Gadeyne S, Deboosere P, Van Oyen H. Socio-economic inequalities in healthy expectancy in Belgium. Public Health 2004;118:3-10.
* Deboosere P, Gadeyne S. Life expectancy and probability of death by gender, region and educational attainment in Belgium 1991-1996 (Levensverwachting en sterftekansen naar geslacht, gewest en onderwijsniveau in België, 1991-1996). Bevolking en Gezin 2002;31:47-73.
* Lorant V, Thomas I, Deliège D, et al. Deprivation and mortality: implication of spatial autocorrelation. Social Science and Medicine 2001;53:1711-9.
* Lorant V, Boland B, Humblet P, et al. Equity in prevention and health care. Journal of Epidemiology and Community Health 2002;56:510-6
* Macintyre S, Ellaway A, Cummins S. Place effects on health: how can we conceptualise, operationalise and measure them? Sci Med 2002;55:125-39
* Mackenbach JP, Huisman M, Andersen O, et al. Inequalities in lung cancer mortality by the educational level in 10 European populations. European Journal of Cancer 2004;40:126-35.