Joinpoint trend analysis software

Joinpoint is statistical software for the analysis of trends using joinpoint models where several different lines are connected at the inflection points or “joinpoints.” The software takes trend data and fits the simplest joinpoint model that the data allow, starting with the minimum number of joinpoints (for example, zero joinpoints is a straight line), and tests whether more joinpoints are statistically significant and must be added to the model, up to the maximum number of joinpoints the data allow. The user can supply the minimum and maximum number of joinpoints to test whether a change in trend is statistically significant. Tests of significance use a Monte Carlo permutation method. The models can incorporate estimated variation for each point (for example, age-adjusted rates), use a Poisson model of variation, and be linear on the log of the response (for example, calculations of annual percentage rate change). Health, United States currently uses Joinpoint software version 4.9.1.0. For more information, see the Joinpoint Trend Analysis Software webpage. (Also see Sources and Definitions, Statistical significance; Statistical testing.)