What’s new in survival data

• Contrasts, which is to say, tests of linear hypotheses involving factor variables and their interactions from the most recently fit model. Tests include ANOVA-style tests of main effects, simple effects, interactions, and nested effects. Effects can be decomposed into comparisons with reference categories, comparisons of adjacent levels, comparisons with the grand mean, and more. New commands contrast and margins, contrast are available after stcox, stcrreg, and streg.
• Pairwise comparisons of means, estimated cell means, estimated marginal means, predictive margins of linear and nonlinear responses, intercepts, and slopes. In addition to ANOVA-style comparisons, comparisons can be made of population averages. New commands pwcompare and margins, pwcompare are available after stcox, stcrreg, and streg.
• Graphs of margins, marginal effects, contrasts, and pairwise comparisons. Margins and effects can be obtained from linear or nonlinear (for example, probability) responses. New command marginsplot is available after stcox, stcrreg, and streg.
• Estimation output improved.
  
  
  • Implied zero coefficients now shown. When a coefficient is omitted, it is now shown as being zero, and the reason it was omitted—collinearity, base, empty—is shown in the standard-error column. (The word “omitted” is shown if the coefficient was omitted because of collinearity.)
  • You can set displayed precision for all values in coefficient tables using set cformat, set pformat, and set sformat. Or you may use options cformat(), pformat(), and sformat() now allowed on all estimation commands.
  • Estimation commands now respect the width of the Results window. This feature may be turned off by new display option nolstretch.
  • You can now set whether base levels, empty cells, and omitted are shown using set showbaselevels, set showemptycells, and set showomitted.
• Gönen and Heller’s K concordance coefficient available after Cox proportional hazards estimation. K is robust to censoring.
• Option addplot() now places added graphs above or below. Graph commands that allow option addplot() can now place the added plots above or below the command’s plots. Affected by this are the commands ltable, stci, stcoxkm, stcurve, stphplot, strate, sts graph, and tabodds.

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See New in Stata 12 for more about what was added in Stata Release 12.