Custom Electronic Health Record Web App

Hello, I am new to vworker and to software design in general. The project I am working on is to create a custom electronic health record web app for customers / patients to be able to track and manage their own bio-metric data such as weight, blood sugar, blood pressure and any labratory testing. I am interested in getting an idea of how much time it would take to create this kind of web app and of course the cost involved. Thanks in advance Take Care Robert