Ask HN: How to think about retention when the goal is churn?

I'm running a medical device startup. We make a treatment for depression. A discussion that often comes up is how we should think about and present our retention numbers. Since, ultimately our goal is to make our users recover from depression, and churn. Im looking for articles or other resources discussing growth and retention for these types of businesses. Dating apps have the same problem to some extent I guess.

This is a great article about growth, but I feel it doesn't really apply to our case: https://www.ycombinator.com/library/59-how-to-set-up-hire-and-scale-a-growth-strategy-and-team