Joinpoint regression in Stata

[Reza Hosseini]

Hello, I would like to know if there is any command to perform joinpoint regression in Stata. Thank you!

[Clyde Schechter]

The term joinpoint regression can mean two different things, and it isn't clear which you mean.

1. A pre-specified joinpoint exists and you want to fit a model that takes that into account. Any Stata regression command applied to variables constructed with the -mkspline- command accomplishes this.

2. You wish to fit a model that is piecewise linear with a joinpoint, but the location of the joinpoint is not known a priori and is to be estimated from the data. There is a user written command -nlhockey- that does this. (And the same author has a command -loghockey- that estimates logistic models with an unknown joinpoint.) -search nlhockey- will get you a link to download these programs.

[Reza Hosseini]

The term joinpoint regression can mean two different things, and it isn't clear which you mean.

1. A pre-specified joinpoint exists and you want to fit a model that takes that into account. Any Stata regression command applied to variables constructed with the -mkspline- command accomplishes this.

2. You wish to fit a model that is piecewise linear with a joinpoint, but the location of the joinpoint is not known a priori and is to be estimated from the data. There is a user written command -nlhockey- that does this. (And the same author has a command -loghockey- that estimates logistic models with an unknown joinpoint.) -search nlhockey- will get you a link to download these programs.

Thank you so much, Clyde. You are always helpful.
The second description is what I am looking for: to fit a model with unknown "joinpoints". I will look into the -nlhockey- and will followup with you if I have additional questions.