Periodic Reporting for period 1 - CASCARA (Uncovering and understanding differences in health behaviours in people with diabetes) Reporting period: 2021-10-01 to 2023-09-30 Summary of the context and overall objectives of the project Diabetes, a disease characterised by high blood glucose levels, affects almost half a billion people worldwide and causes over 8 percent of global deaths. It doubles the risk of cardiovascular disease (CVD), causes 2.6% of global cases of blindness, 80% of all cases of end-stage renal disease, and increases the risk of lower-extremity amputations up to 20-fold. Diabetes caused additional worldwide healthcare costs of USD 760 billion in 20192, and reduces labour productivity in low-, middle- and high-income countries. This project aims to complement this evidence by addressing the challenge of diabetes focusing on the role of behaviour change after a diabetes diagnosis. The main goals are to (1) identify the change in health behaviours as a result of a diabetes diagnosis; (2) identify socio-economic and demographic characteristics that, together with clinical factors, affect the uptake of healthier behaviours and (3) identify the contribution of behaviour change to changes in risk factors for the other diseases resulting from diabetes. Taken together, the resulting insights will help inform the design of more effective policies to increase behaviour change in people with diabetes. The project was terminated prior to its complete conclusion and only one objective could be achieved during the project time. The results of the analysis show that in all three regions (the US, England and continental Europe), health behaviours (smoking and physical activity) remain mostly unaffected by a diabetes diagnosis. Smoking is reduced shortly after the diagnosis but returns to pre-diagnosis levels as time progresses. Physical activity levels remain unchanged. Body fat as measured by body mass index, however, decreases significantly in all surveys after the diagnosis and this reduction continues over time. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far Work performed during the project period included the gaining data access to three Health and Retirement Studies: Survey of Health, Ageing and Retirement in Europe (SHARE), English Longitudinal Study of Ageing (ELSA) and US Health and Retirement Study (HRS) and harmonising them to analyse them jointly. It further included the drafting of a career development plan and attending several training courses. To investigate the effect of a diabetes diagnosis on health behaviours newly developed econometric methods were used, so called difference-in-difference methods that are able to account for issues caused by treatments, here the diabetes diagnosis, happening in different years. Results indicate that hat in all three regions (the US, England and continental Europe), health behaviours (smoking and physical activity) remain mostly unaffected by a diabetes diagnosis. Smoking is reduced shortly after the diagnosis but returns to pre-diagnosis levels as time progresses. Physical activity levels remain unchanged. Body fat as measured by body mass index, however, decreases significantly in all surveys after the diagnosis and this reduction continues over time. However, it requires further investigation using more detailed data also covering pharmacological treatments, to see what is causing the apparent weight loss. The analysis did not uncover strong differences by gender, age at first diagnosis or education level. Results were presented at the European Health Economics Association Congress 2022 in Oslo and at the 2022 meeting of the Internation Diabetes Epidemiology Study Group (IDEG), as well as internally at the Luxembourg Institute for Socio-Economic research. The results of this analysis will be submitted to an international peer-reviewed journal in 2023. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) Progress beyond the state of the art was achieved through the use of very recently developed empirical methods to account for heterogeneous treatment effects in the application of difference-in-difference models. Using this method allowed me to improve upon prior research by accounting for potential biases caused by heterogeneous treatment effects and further allowed an investigation of changes in health behaviours after a diabetes diagnosis over time. The result of this project show that effects of a diabetes diagnosis on health behaviours are limited and similar across different high-income countries and regions, namely the United States, England and continental Europe and that there are no strong differences by gender or education levels. Because the project had to be terminated earlier than initially planned, there are no further results to be expected from this project. The project and the resulting academic publications have the goal of spurring further research into the reasons for weight loss after a diabetes diagnosis and how people with diabetes can be better supported in their efforts to implement healthy behaviours.
