Researchers at the MRC Epidemiology Unit at the University of Cambridge in collaboration with colleagues at the University of Michigan performed a study where they examined the effects of early screening and initiation of treatment for patients with Type 2 Diabetes Mellitus (T2DM) in comparison to those without a screening process, which in turn led to a delayed diagnosis. In the course of this study, the researchers accessed a European study called ADDITION that had recruited patients aged between 40 and 69 years without proper knowledge of their medical history, from as many as 343 general practices across the United Kingdom, Denmark and the Netherlands, and a computer simulation model (the Michigan Model) of diabetes progression. This model gave an idea of the complications, co-morbidities, quality-of-life, and costs of diabetes, and provided researchers with estimates of cardiovascular events and mortality, which normally affects patients within the late progression of diabetes.
ADDITION was aimed at figuring out two main research goals: 1) whether routine screening and treatment was feasible in patients, and 2) whether intensive treatment for patients diagnosed with type 2 diabetes could prevent or reduce the risks of adverse consequences like heart attacks, stroke, angioplasty, bypass surgery, amputation of limbs or eventual death. The results of this study showed that though routine screening was feasible, there was no statistically significant improvement in the outcomes of patients with diabetes with intensive treatment regimes. Researchers determined that the reason for this was the high quality of treatment being provided as a part of the routine therapy for type 2 diabetes.
One question that remained unanswered in this study was: what effects would a delay in screening or no screening at all cause in patients with type 2 diabetes? To ascertain the benefits of an early screening process, the Michigan model of simulation was used as a reference. Normally across Europe, the clinical onset of T2DM occurs around 6 years before diagnosis, so it was important to assess the importance of screening and consequent improvements in prognosis, if any, in patients with the condition.
In their assessment of scenarios where there was a delay in screening by 3 or 6 years, there were increased risks of T2DM patients experiencing cardiovascular complications and mortality rates as compared to early screening. In fact, 10 years beyond baseline, it was predicted that there was a 29% reduction in relative risk of a cardiovascular disease event and a 20% reduction in all-cause mortality risks compared with a delay of six years in diagnosis and treatment, amounting to a 7.5% reduction in the absolute risk of adverse cardiovascular outcome in this population, and a 3.6% reduction in the absolute risk of mortality.
According to Professor William Herman of the University of Michigan, first author on the paper: “Comparing the results of our simulations with the real-world data gave us confidence that our model successfully predicts the impact of delaying diagnosis of type 2 diabetes on future cardiovascular health outcomes. Diabetes can be debilitating for patients and costly for healthcare. This research shows that the early identification of diabetes has major health benefits, and supports the introduction of measures such as screening to reduce the time between development of type 2 diabetes and its treatment.”
Professor Nick Wareham, senior author on the paper and Director of the MRC Epidemiology Unit, University of Cambridge, added: “This work shows the value of public health modeling to assess impacts and interventions for diseases such as type 2 diabetes that pose an increasing public health challenge. ADDITION-Europe is a large, high quality study, but even so there are limitations in how much direct clinical observation can tell us about the costs and benefits of screening. Computer simulations add an extra dimension which we hope will guide future research as well as the development of public health policy.”
