Optimal screening schedules for disease progression with application to diabetic retinopathy

Abstract

Clinical management of chronic diseases requires periodic evaluations. Subjects transition between various levels of severity of a disease over time, one of which may trigger an intervention that requires treatment. For example, in diabetic retinopathy, patients with type 1 diabetes are evaluated yearly for either the onset of proliferative diabetic retinopathy (PDR) or clinically significant macular edema (CSME) that would require immediate treatment to preserve vision. Herein, we investigate methods for the selection of personalized cost-effective screening schedules and compare them with a fixed visit schedule (e.g., annually) in terms of both cost and performance. The approach is illustrated using the progression of retinopathy in the DCCT/EDIC study.

Keywords: Diabetic retinopathy; Markov models; Optimal screening schedule; Undetected time.

Fig. 1

Possible instantaneous transitions among the five retinopathy states.

Fig. 2

Incidence functions for PDR/CSME, stratified by the initial state.

Fig. 3

Total cost as a function of the time to the next visit for (solid line) and (dashed line), stratified by the current retinopathy state. Note that the axes differ for each intermediate state to best display the change in costs as the screening interval changes.