We deal with a joinpoint regression model, i.e. with a piecewise linear continuous regression. This model is common in many fields and finds various interesting applications.
We give a description of the Joinpoint Regression Program, a special software developed for the estimation of the joinpoint regression models. The library segmented available in program R is presented as well.
We provide a practical comparison of these two programs based on analyses of several data sets, simulated as well as real data. Advantages, disadvantages, and possible problems with estimation are discussed.