The "Progression of Persons Screened for Diabetes" figure illustrates the screening and diagnostic testing process and shows where costs are incurred. The top half of the figure shows the process for persons who are screened and have diabetes. The bottom half of the figure shows the process for persons who are screened and do not have diabetes. The figure is divided vertically into 3 timeframes: the time of onset of diabetes, the time of diabetes detection by screening (5 years after onset); and the time of diabetes diagnosis clinically (10 years after onset).
For those who are screened and found to have diabetes, the process begins with diabetes onset. Five years after onset, diabetes is detected by screening, which incurs costs. If the screening result is true positive, diagnostic testing is undergone, which incurs the cost of 2 diagnostic tests.
The figure assumes that the diagnostic tests will be true positive, and that the interventions will start at 5 years after onset. If the screening result is false negative, those persons live with undiagnosed diabetes until they are diagnosed clinically at 10 years after onset.
Persons who are screened and found not to have diabetes also incur a cost for screening. If their screening results are true-negative, they exit the model, diagnosed as not having diabetes. If their screening results are false-positive, they incur cost for one diagnostic test with a true negative result, then exit the model diagnosed as not having diabetes.