How to Write a Profile
Congratulations, you are an author, editor or contributor to a new QIBA Profile. This is much like being a parent (you will experience the "terrible 2's" and those rambunctious teenage years); challenging but rewarding. Also, it does indeed "take a village" to raise a new Profile. A diverse body of expertise is needed to nail down the intended clinical use cases for the biomarker, decide on an appropriate technical performance target, determine the key sources of variability that affect the performance, and draft clear requirements that eliminate, compensate, or characterize each of those sources of variability. You will need radiologists, physicists, bio-statisticians, technologists, and engineers, at the least.
Review the basic QIBA Concepts
These are terms and ideas that will be referred to throughout the rest of this.
Get the QIBA Profile Template
The template provides a sense of the content you will be developing. Don't skip the Executive Summary, which highlights the structure, and read the Guidance comment boxes, which describe issues and considerations you should start thinking about. (Really. Don't skip the Guidance comment boxes)
Review the Claim Guidance
The Biomarker Performance Claim is the anchor of the Profile. The remainder of the profile is the Requirements necessary to achieve the claim, and the Assessment Procedures necessary to test the requirements.
As you will see in the Claim Guidance, coming up with good Claim(s) is not trivial. Expect it to be an iterative process as your experience doing the groundwork and drafting the profile gives you a better appreciation. New literature and evolving technology will also contribute to making it a bit of a moving target.
Review the Guidance on Vetting Requirements & Expressing Requirements
After the Claim, the remainder of the profile is the Requirements necessary to achieve the claim, and the Assessment Procedures (as necessary) to test the requirements.
One of the hardest parts in drafting a Profile is figuring out what goes in, where to put it, what to cut, and how to word things.
Consider your Ground Truth Strategy
The concepts of biomarker performance (for example in terms of bias or repeatability) and sources of variance presume some understanding of the "true value" of measurements.
Plan and Conduct Groundwork Projects
This is where you figure out what the critical sources of variance are for your biomarker and what requirements you need to write to actually achieve the Claim.
Hey, how hard can that be? Seriously though, consult a biostatistician. It's hard to give general guidance for this.
Further Reading
The QIBA Process pages provide procedures and "cookbooks" for various parts of the QIBA profile development process.
There's a quick link to the Processes in the navigation bar to the left no matter where you are on the Wiki.
If there are topics you can't find, or information you think is is missing, let someone know so we can add it to our ToDo list.