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From | "T. Alp Ozkan" <alpozkan@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | st: pairwise comparison of a Survival data |
Date | Tue, 17 Apr 2012 13:43:16 +0300 |
Dear listers, I'm working on a data of renal carcinoma. In 2010 TNM cancer staging classification have been changed. According to this I want to validate new TNM classification. In a part of this analyse I need a pairwise survival comparisons of consecutive T stages (like T1avsT1b or T1b vs T2a) First I used stcox for TNM 2010 and test each other. . stcox i.pT2010 failure _d: CSS analysis time _t: followuptimemonths No. of subjects = 1889 Number of obs = 1889 No. of failures = 151 Time at risk = 63708.43333 LR chi2(6) = 144.47 Log likelihood = -949.97419 Prob > chi2 = 0.0000 ------------------------------------------------------------------------------ _t | Haz. Ratio Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- pT2010 | 11 | 2.879476 1.326301 2.30 0.022 1.16747 7.10201 21 | 5.796228 2.753477 3.70 0.000 2.284469 14.70638 22 | 10.66265 5.002194 5.04 0.000 4.251472 26.74184 30 | 14.05566 6.091828 6.10 0.000 6.010826 32.86763 31 | 48.52258 24.10974 7.81 0.000 18.32321 128.495 40 | 21.73121 9.848165 6.79 0.000 8.939966 52.82409 ------------------------------------------------------------------------------ . test 11.pT2010 21.pT2010 ( 1) 11.pT2010 = 0 ( 2) 21.pT2010 = 0 chi2( 2) = 14.33 Prob > chi2 = 0.0008 As I read more help documents I realized another stratification with sts test variable, strata(subvariable) command. Would you help me to understand which one is suitable for this purpose? Thanks Alp . sts test pT2010, strata (T1bvsT2a) failure _d: CSS analysis time _t: followuptimemonths Stratified log-rank test for equality of survivor functions | Events Events pT2010 | observed expected(*) -------+------------------------- T1b | 22 28.29 T2a | 17 10.71 -------+------------------------- Total | 39 39.00 (*) sum over calculations within T1bvsT2a chi2(1) = 5.16 Pr>chi2 = 0.0231 * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/