I am analyzing data from a longitudinal data on hypertension. The outcome is all-cause mortality (yes or no). The literature says that systolic blood pressure reduction has benefit up to a low point (nadir), further reductions beyond the low point are harmful.

So the data will be either J or U shaped (positive effects of blood pressure reduction up to a point and thereafter negative effects of blood pressure reduction).

I would appreciate any Stata resources (code, textbooks, discussions from this forum, commands) on how to analyze this type of data. Right now, I am thinking of doing a type of non-linear logistic regression it I could be wrong.

Thank you,
Al Bothwell