topic how to replicate two-piecewise linear regression graph in Statistical Procedures

how to replicate two-piecewise linear regression graph

CathyVI — Wed, 12 May 2021 00:38:08 GMT

Hi,

I am trying to replicate this graph. This is from a study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7214907/

This is a two-piecewise linear regression model. I will like to know the sas code which can be used to replicate this graph.

Re: how to replicate two-piecewise linear regression graph

WarrenKuhfeld — Wed, 12 May 2021 01:33:24 GMT

Look at proc transreg.

Re: how to replicate two-piecewise linear regression graph

Ksharp — Wed, 12 May 2021 12:08:05 GMT

Calling @Rick_SAS

Re: how to replicate two-piecewise linear regression graph

Ksharp — Wed, 12 May 2021 12:14:43 GMT

proc sgplot data=sashelp.heart(obs=1000);
loess x=weight y=height/clm nomarkers;
run;

Re: how to replicate two-piecewise linear regression graph

Rick_SAS — Wed, 12 May 2021 12:39:50 GMT

See the article "Piecewise regression models and spline effects" for a discussion, example, and code. The example uses PROC GLIMMIX, but also includes a reference to the PROC TRANSREG documentation, which contains a second example.

The example assumes that the two pieces of the model both have the same form (for example, linear or quadratic). If you want to mix-and-match models on separate domains, you can use PROC NLIN to construct a segmented regression model.