Our results provide evidence for a profound negative impact of diabetes on workforce participation in France. Indeed, we found that, among employees of the GAZEL cohort, diabetes is associated with an overall 60–70% increase in the risks of work disability and early retirement and with a sevenfold increase in the risk of death while in the labor force. The effect of diabetes on disability is largely attributable to obesity. These substantially increased risks of work cessation associated with diabetes translate into an absolute decrease of over 1 year spent in employment between 35 and 60 years for employees with diabetes compared with those without diabetes. Retirement accounts for the major part (64%) of this difference.
Strengths of this study, which lend weight to these conclusions, include prospective data from a large occupational cohort, constituted of a diverse population of white- and blue-collar employees from all regions of France, with long-term follow-up that is almost 100% complete. Available information on occupational status throughout the career in the company is particularly comprehensive and accurate since it has been obtained directly from the company administrative records. In addition to ensuring highly reliable measures of the outcomes of interest, such information allowed us to account for occupational characteristics early in an individual’s career in our analyses and thus to provide estimates of the burden of diabetes independent of these major occupational determinants of workforce participation.
Our study has several limitations. First, information on diabetes was self-reported. Although accuracy of diabetes self-report is high (12
), such a definition excludes undiagnosed cases of the disease, which are incorrectly considered as free of diabetes. However, only 13% of diabetic adults aged 55–74 years are estimated to be undiagnosed in France (13
). Moreover, to be considered as patients with diabetes, participants in our study had not only to self-report diabetes once during follow-up but also to consistently self-report the disease over time after the first report. This probably improved the identification of true cases of diabetes compared with a definition based on a unique occurrence of self-reported diabetes. Although our definition may have led to exclude some cases of diabetes episodically self-reported, internally consistent results are obtained using either definition, as shown in our sensitivity analysis. In addition, available data did not allow us to distinguish between type 1 and type 2 diabetes. However, because our analyses were restricted to incident cases of diabetes occurring after enrollment in the GAZEL cohort, i.e., after the age of 35 years, our results mostly pertain to type 2 diabetes.
There are several considerations suggesting that the magnitude of diabetes impact on workforce participation may have been underestimated in our study. First, EDF-GDF employees have a particularly high level of job security; moreover, some categories of workers (e.g., those self-employed and agricultural workers), whose occupational status may be particularly vulnerable to health problems, are not represented in the company (11
). Second, to provide valid estimates of the impact of diabetes on work cessation, our analyses were restricted to incident cases of diabetes appearing after enrollment in the cohort, i.e., later than 1989. Thus cases of diabetes that occurred earlier in employees’ careers were excluded. The impact of these early-onset cases on work cessation before 1989 could not be accounted for in our study since the GAZEL cohort was restricted to employees still working in 1989. However, a complementary analysis suggested that the diabetes-related increase in the risk of disability during follow-up may be more marked for cases prevalent in 1989 (results not shown). Third, because a large proportion of EDF-GDF employees are given the opportunity to retire between 55 and 60 years, retirement before 55 years rather than 60 years may constitute a better indicator of early retirement in this population. Diabetes-related increase in the risk of early retirement was substantially higher between 35 and 55 years (HR 2.1 [95% CI 1.7–2.5]) than between 35 and 60 years (HR 1.6 [95% CI 1.5–1.8]).
To our knowledge, this study is the first to provide evidence for a significant impact of diabetes on work cessation in France, a country with a system of universal social protection. Our findings of increased risks of disability, retirement, and death among employees with versus without diabetes are consistent with reports based on data from the Health and Retirement Study in the U.S. (9
). This shows that such deleterious consequences of diabetes on workforce participation occur in the context of very different systems of social protection.
Diabetes is unevenly distributed across socioeconomic strata, with higher prevalence of the disease reported in the most deprived groups of the population (14
). This suggests that individuals with diabetes may be more prone than others to hold adverse occupational conditions, exposing them to an increased risk of unemployment. This could explain, at least in part, the differences formerly reported between individuals with versus without diabetes with regard to employment status (6
). In our study, all participants were employed by the same company and thus benefited from a comparable level of job security; moreover, we were able to provide estimates accounting for occupational characteristics before diabetes onset. Thus our findings add significant knowledge to the existing literature by providing evidence for an independent effect of diabetes on work cessation.
Further research is needed to ascertain the generalizability of our results outside the GAZEL cohort study, and more generally outside France. The French pattern of early transitions out of employment is characterized by a low age of retirement and by the importance of transitions through unemployment insurance and preretirement schemes, resulting in lower recourse to disability compared with other countries (17
). Despite these differences, data from the Survey of Health, Ageing and Retirement in Europe (SHARE) suggest that the overall burden of health impairment on work cessation does not differ in France compared with other European countries (18
). This suggests that although the patterns of transitions out of employment are likely to be country specific, the negative impact of diabetes on workforce participation that we show might be fairly generalizable to other settings. Our results pertain to the population of working age, i.e., aged less than 60 years in France, a country with universal access to a high quality of medical care. The impact of diabetes on work cessation might be even greater in countries with older retirement ages or lower access to quality healthcare.
Diabetes can affect individuals’ ability to maintain employment through different pathways. This can happen directly through impairment of bodily functions arising from diabetes complications, including loss of vision, amputations, or mobility limitations (16
); workplace discrimination encountered by employees with diabetes may also play a role (20
). Moreover, because diabetes is frequently associated with other health problems, comorbidities can constitute additional barriers to employment. Obesity has been shown to impair employment status in several studies (21
); in addition, our results suggest that differences in BMI between employees with versus without diabetes explain a significant part of the effect of diabetes on disability. Studies also suggest that macrovascular comorbid conditions (25
) and depression (19
) are associated with higher rates of unemployment among people with diabetes.
In conclusion, the current study provides evidence that diabetes substantially weighs on employees’ chances of maintaining in employment. This effect of diabetes has major social and economic consequences for patients, employers, and society, a burden that is likely to increase as diabetes becomes more and more common in the working-aged population. Limiting the social and economic burden of diabetes is a major challenge to be addressed at different levels, including the health care system, employers, and social workers.