I am trying to calculate sample size for my study. I am interested in using more sensitive marker to diagnose an outcome faster and more precisely. The incidence of given outcome diagnosed with currently used marker is ~15% and I expect it to be higher (but I can not reliably predict how much higher).
The goal of my study is twofold:
- Assess the incidence of outcome using new biomarker
- Measure some biomarkers with potential predictive value for the outcome
What would be an optimal way to calculate sample size for this study?
I would be very grateful for any help.