The care and course of diabetes: differences according to level of education
Introduction
Diabetes is no exception to the rule that socioeconomic status and health are inversely related. The incidence of type 2 diabetes is higher in groups with a low socioeconomic status [1], [2], and total diabetes prevalence (of which 80–90% may be considered type 2 diabetes) [3] is higher in those groups [4], [5], [6], [7], [8], [9]. Reports with regard to the direction of the association between socioeconomic status and the incidence of insulin-dependent diabetes mellitus (type 1 diabetes) conflict: a higher incidence in groups with a high social class has been reported [10], [11], [12], some report no association between socioeconomic status and type 1 diabetes incidence [2], [13], while others demonstrated a higher incidence among the less well-off [14], [15]. There is recent evidence of shorter survival in type 1 diabetes patients with a low socioeconomic status [16].
Patients with either type of diabetes and a low socioeconomic status are at higher risk for complications, which is the focus of this paper. The risk for coronary artery disease is higher in type 2 diabetes patients [17], [18]. Higher prevalences of proliferative retinopathy and macroalbuminuria have been demonstrated in type 1 diabetes populations [19], [20]. This may, at least partly, be attributable to poorer glycaemic control for both types of diabetes in lower social strata [20], [21], [22], which may in turn be a result of socioeconomic differences in the uptake of diabetes checks [20]. Research from the USA indicates that diabetes patients with fewer years of education have a smaller chance to have had regular ophthalmic examinations [23], [24], which will help prevent retinopathy and vision loss [25]. Two recent studies suggest that use of health care facilities and quality of care may play a role in preventing premature mortality in socially disadvantaged diabetes patients [16], [26] without investigating direct links between the two due to lack of data on health service use.
We explored whether service use or diabetes checks would occur less in lower educated diabetes patients in comparison to their fellow patients with a higher socioeconomic status. In addition, we tested the hypothesis that the course of diabetes was more unfavourable among those with a low level of education, by examining the differences in prevalence of symptoms of complications between 1991 and 1993 in a cohort study. Finally, we tried to supplement existing knowledge in establishing the contribution of differential service use to differences in the course of diabetes by level of education while using a population-based design.
Section snippets
Study population
The source of the data is the Longitudinal Study on SocioEconomic Differences in the Utilisation of Health Services (LS-SEDUHS). The LS-SEDUHS is part of the GLOBE study, a longitudinal study that started in 1991 in the southeast of The Netherlands, aiming to explain socioeconomic inequalities in health. The design and objective of the GLOBE study have been described in detail elsewhere [27]. The cohort of the GLOBE study is based on a sample of non-institutionalised Dutch nationals aged 15–74
Results
The use of services according to level of education are listed in Table 2. Checks are listed in Table 3; checks of blood and blood pressure are not included in this table, because nearly everyone reported these checks and a meaningful contrast did not exist. Controls by the general practitioner were reported by a larger proportion of lower educated people compared to the reference category (statistically significant for those with lower secondary school or lower vocational training), as was
Discussion
In a group of 173 respondents to a health survey who reported diabetes, we demonstrated socioeconomic differences in the uptake of medical care relevant for the disease, controlling for the severity of the disease and other relevant confounders. At the same time we showed a considerable and sometimes statistically significant difference in the course of diabetes by level of education over a 2-year period, measured as the difference in prevalence of complications between 1991 and 1993. A causal
Acknowledgements
This project was supported by a grant from the Health Insurance Executive Board (Ziekenfondsraad). It is part of the GLOBE study (Gezondheid en LevensOmstandigheden Bevolking Eindhoven en omstreken), a large-scale research project on health and living conditions of the population of Eindhoven and surroundings. The GLOBE study is conducted by the Department of Public Health, Erasmus University Rotterdam, in collaboration with the Public Health Services of the city of Eindhoven and Southeast
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