Probabilistic approach to developing nephropathy in diabetic patients with retinopathy

It is well known that diabetes is a risk factor for many complications including diabetic retinopathy and nephropathy. An interesting question is whether a diabetic patient who has developed a retinopathy develops a nephropathy sooner. We approached this problem by calculating the conditional probability that a diabetic patient will develop a second complication, given that they had already developed the first complication. We also propose the application of Bayes' formula to estimate the probability of developing the second complication, given that the first complication had developed previously. We compared these two methods by applying them to analyse 5473 patients with type 2 diabetes. The results of our experience are described.