The SAS System 1 Obs treatment cold count 1 placebo 1 31 2 placebo 0 109 3 ascorb 1 17 4 ascorb 0 122 The SAS System 2 The LOGISTIC Procedure Model Information Data Set WORK.COLD Response Variable cold Number of Response Levels 2 Frequency Variable count Model binary logit Optimization Technique Fisher's scoring Number of Observations Read 4 Number of Observations Used 4 Sum of Frequencies Read 279 Sum of Frequencies Used 279 Response Profile Ordered Total Value cold Frequency 1 0 231 2 1 48 Probability modeled is cold=1. Class Level Information Design Class Value Variables treatment ascorb 1 placebo -1 Model Convergence Status Convergence criterion (GCONV=1E-8) satisfied. The SAS System 3 The LOGISTIC Procedure Model Fit Statistics Intercept Intercept and Criterion Only Covariates AIC 258.184 255.312 SC 261.815 262.575 -2 Log L 256.184 251.312 Testing Global Null Hypothesis: BETA=0 Test Chi-Square DF Pr > ChiSq Likelihood Ratio 4.8717 1 0.0273 Score 4.8114 1 0.0283 Wald 4.6934 1 0.0303 Type 3 Analysis of Effects Wald Effect DF Chi-Square Pr > ChiSq treatment 1 4.6934 0.0303 Analysis of Maximum Likelihood Estimates Standard Wald Parameter DF Estimate Error Chi-Square Pr > ChiSq Intercept 1 -1.6141 0.1647 96.0887 <.0001 treatment ascorb 1 -0.3567 0.1647 4.6934 0.0303 Odds Ratio Estimates Point 95% Wald Effect Estimate Confidence Limits treatment ascorb vs placebo 0.490 0.257 0.934 The SAS System 4 The LOGISTIC Procedure Association of Predicted Probabilities and Observed Responses Percent Concordant 34.1 Somers' D 0.174 Percent Discordant 16.7 Gamma 0.342 Percent Tied 49.2 Tau-a 0.050 Pairs 11088 c 0.587 The SAS System 5 Obs treatment cold count _LEVEL_ predict lower upper 1 placebo 1 31 1 0.22143 0.16026 0.29767 2 placebo 0 109 1 0.22143 0.16026 0.29767 3 ascorb 1 17 1 0.12230 0.07740 0.18795 4 ascorb 0 122 1 0.12230 0.07740 0.1879