The SAS System.docx

1、The SAS System The SAS SystemThe LOGISTIC ProcedureModel InformationData SetWORK.EXAMPLE19_2Response VariableyNumber of Response Levels2Number of Observations1649Link FunctionLogitOptimization TechniqueFishers scoring Response ProfileOrderedValueyTotalFrequency1172020929Backward Elimination Procedur

2、eClass LevelInformationClassValueDesign Variables12x7110201300Step 0. The following effects were entered:Intercept x1 x2 x3 x4 x5 x6 x7 Model Convergence StatusConvergence criterion (GCONV=1E-8) satisfied. Model Fit StatisticsCriterionInterceptOnly Interceptand CovariatesAIC2261.4392178.468SC2266.84

3、72227.139-2 Log L2259.4392160.468 Testing Global Null Hypothesis: BETA=0TestChi-SquareDFPrChiSqLikelihood Ratio98.97118.0001Score95.96968.0001Wald90.53968ChiSqLikelihood Ratio98.86937.0001Score95.85017.0001Wald90.41487ChiSq0.101710.7498Step 2. Effect x5 is removed:Model Convergence StatusConvergence

4、 criterion (GCONV=1E-8) satisfied. Model Fit StatisticsCriterionInterceptOnly Interceptand CovariatesAIC2261.4392174.676SC2266.8472212.532-2 Log L2259.4392160.676 Testing Global Null Hypothesis: BETA=0TestChi-SquareDFPrChiSqLikelihood Ratio98.76216.0001Score95.75176.0001Wald90.31566ChiSq0.208920.900

5、8Step 3. Effect x1 is removed:Model Convergence StatusConvergence criterion (GCONV=1E-8) satisfied. Model Fit StatisticsCriterionInterceptOnly Interceptand CovariatesAIC2261.4392175.263SC2266.8472207.711-2 Log L2259.4392163.263 Testing Global Null Hypothesis: BETA=0TestChi-SquareDFPrChiSqLikelihood

6、Ratio96.17555.0001Score93.27065.0001Wald88.07735ChiSq2.796630.4241Step 4. Effect x4 is removed:Model Convergence StatusConvergence criterion (GCONV=1E-8) satisfied. Model Fit StatisticsCriterionInterceptOnly Interceptand CovariatesAIC2261.4392176.106SC2266.8472203.146-2 Log L2259.4392166.106 Testing

7、 Global Null Hypothesis: BETA=0TestChi-SquareDFPrChiSqLikelihood Ratio93.33264.0001Score90.84014.0001Wald86.04294ChiSq5.555440.2349NOTE:No (additional) effects met the 0.05 significance level for removal from the model.Summary of Backward EliminationStepEffectRemovedDFNumberInWaldChi-SquarePrChiSq1x

8、3160.10170.74982x5150.10720.74343x1142.58620.10784x4132.73490.0982 Type III Analysis of EffectsEffectDFWaldChi-SquarePrChiSqx2116.5718.0001x6162.9176ChiSqIntercept10.46730.29762.46470.1164x210.23270.057216.5718.0001x61-0.60890.076862.9176.0001x711-0.50040.119317.5977.0001x721-0.34030.18493.38930.065

9、6 Odds Ratio EstimatesEffectPoint Estimate95% WaldConfidence Limitsx21.2621.1281.412x60.5440.4680.632x7 1 vs 30.6060.4800.766x7 2 vs 30.7120.4951.022 Association of Predicted Probabilities andObserved ResponsesPercent Concordant61.1Somers D0.275Percent Discordant33.6Gamma0.290Percent Tied5.3Tau-a0.1

10、35Pairs668880c0.638 Wald Confidence Interval for Adjusted Odds RatiosEffectUnitEstimate95% Confidence Limitsx21.00001.2621.1281.412x61.00000.5440.4680.632x7 1 vs 31.00000.6060.4800.766x7 2 vs 31.00000.7120.4951.022The SAS SystemThe PHREG ProcedureModel InformationData SetWORK.EXAMPLE19_3Dependent Va

11、riabletimeCensoring VariablecaseCensoring Value(s)0Ties HandlingDISCRETE Summary of the Number of Event and Censored ValuesStratumidTotalEventCensoredPercentCensored1121150.002221150.003321150.004421150.005521150.006621150.007721150.008821150.009921150.00101021150.00111121150.00121221150.00131321150

12、.00141421150.00151521150.00161621150.00171721150.00181821150.00191921150.00202021150.00212121150.00222221150.00232321150.00242421150.00252521150.00262621150.00272721150.00282821150.00292921150.00303021150.00313121150.00323221150.00333321150.00343421150.00353521150.00363621150.00373721150.00383821150

13、.00393921150.00404021150.00414121150.00424221150.00434321150.00444421150.00454521150.00464621150.00474721150.00484821150.00494921150.00505021150.00515121150.00525221150.00535321150.00545421150.00555521150.00565621150.00575721150.00585821150.00595921150.00606021150.00616121150.00626221150.00636321150

14、.00646421150.00656521150.00666621150.00676721150.00686821150.00696921150.00707021150.00717121150.00727221150.00737321150.00747421150.00757521150.00767621150.00777721150.00787821150.00797921150.00808021150.00818121150.00828221150.00838321150.00848421150.00858521150.00868621150.00878721150.00888821150

15、.00898921150.00909021150.00919121150.00929221150.00939321150.00949421150.00959521150.00969621150.00979721150.00989821150.00999921150.0010010021150.0010110121150.0010210221150.0010310321150.0010410421150.0010510521150.0010610621150.0010710721150.0010810821150.0010910921150.0011011021150.0011111121150

16、.0011211221150.0011311321150.0011411421150.0011511521150.0011611621150.0011711721150.0011811821150.0011911921150.0012012021150.0012112121150.0012212221150.0012312321150.0012412421150.0012512521150.0012612621150.0012712721150.0012812821150.0012912921150.0013013021150.0013113121150.0013213221150.00133

17、13321150.0013413421150.0013513521150.0013613621150.0013713721150.0013813821150.0013913921150.0014014021150.0014114121150.0014214221150.0014314321150.0014414421150.0014514521150.0014614621150.0014714721150.0014814821150.0014914921150.0015015021150.0015115121150.0015215221150.0015315321150.00154154211

18、50.0015515521150.0015615621150.0015715721150.0015815821150.0015915921150.0016016021150.0016116121150.0016216221150.0016316321150.0016416421150.0016516521150.0016616621150.0016716721150.0016816821150.0016916921150.0017017021150.0017117121150.0017217221150.0017317321150.0017417421150.0017517521150.001

19、7617621150.0017717721150.0017817821150.0017917921150.0018018021150.0018118121150.0018218221150.0018318321150.0018418421150.0018518521150.0018618621150.0018718721150.0018818821150.0018918921150.0019019021150.0019119121150.0019219221150.0019319321150.0019419421150.0019519521150.0019619621150.0019719721150.0019819821150.0019919921150.0020020021150.0020120121