I am working with a database of diseased and non-diseased patients. I would like to recommend an optimal age cut off for disease screening. The common problem with screening is that it creates a large number of false positive, which is directly related to the positive predictive (PPV). The PPV in turn, is affected by the prevalence.
In a nutshell, I would like to derive an age that provides the best trade-off where I will be able to:
- retain a large percentage of the diseased patients and
- drop a large percentage of non-diseased patients.
The central idea is to avoid unnecessary screening of patients who have relatively low probability of having the disease.
In this case, the independent variable is the age while the dependent variable diseased, non diseased.
I tried running an ROC curve to get the optimal balance by the comparing highest Youden statistic.
I'll like to know if there's a better way to do this or if what I am is acceptable. Please do let me know if you anything I've mentioned is unclear. Thank you very much.