%newsas(nwk08t01);
title  'Selecting the best predictors';
title2 'NWK Table 8.1 Surgical unit example';
DATA SURGICAL;
   INPUT BCSCORE PINDEX EFTEST LFTEST STIME;
   Label BCSCORE='Blood clotting score'
         PINDEX ='Prognostic Index'
         EFTEST ='Enzyme function test'
         LFTEST ='Liver function test'
         STIME  ='Survival time'
         LSTIME ='Log(Survival time)';
   CASE = _N_;
   LSTIME=LOG10(STIME);
CARDS;
 6.7 62  81 2.59 200
 5.1 59  66 1.70 101
 7.4 57  83 2.16 204
 6.5 73  41 2.01 101
 7.8 65 115 4.30 509
 5.8 38  72 1.42  80
 5.7 46  63 1.91  80
 3.7 68  81 2.57 127
 6.0 67  93 2.50 202
 3.7 76  94 2.40 203
 6.3 84  83 4.13 329
 6.7 51  43 1.86  65
 5.8 96 114 3.95 830
 5.8 83  88 3.95 330
 7.7 62  67 3.40 168
 7.4 74  68 2.40 217
 6.0 85  28 2.98  87
 3.7 51  41 1.55  34
 7.3 68  74 3.56 215
 5.6 57  87 3.02 172
 5.2 52  76 2.85 109
 3.4 83  53 1.12 136
 6.7 26  68 2.10  70
 5.8 67  86 3.40 220
 6.3 59 100 2.95 276
 5.8 61  73 3.50 144
 5.2 52  86 2.45 181
11.2 76  90 5.59 574
 5.2 54  56 2.71  72
 5.8 76  59 2.58 178
 3.2 64  65 0.74  71
 8.7 45  23 2.52  58
 5.0 59  73 3.50 116
 5.8 72  93 3.30 295
 5.4 58  70 2.64 115
 5.3 51  99 2.60 184
 2.6 74  86 2.05 118
 4.3  8 119 2.85 120
 4.8 61  76 2.45 151
 5.4 52  88 1.81 148
 5.2 49  72 1.84  95
 3.6 28  99 1.30  75
 8.8 86  88 6.40 483
 6.5 56  77 2.85 153
 3.4 77  93 1.48 191
 6.5 40  84 3.00 123
 4.5 73 106 3.05 311
 4.8 86 101 4.10 398
 5.1 67  77 2.86 158
 3.9 82 103 4.55 310
 6.6 77  46 1.95 124
 6.4 85  40 1.21 125
 6.4 59  85 2.33 198
 8.8 78  72 3.20 313
PROC PRINT data=SURGICAL;
     ID CASE;
PROC CORR data=SURGICAL;
   VAR LSTIME BCSCORE PINDEX EFTEST LFTEST;
PROC reg data=surgical;
   MODEL LSTIME= BCSCORE PINDEX EFTEST LFTEST / selection=RSQUARE CP SSE MSE;
 
PROC reg data=SURGICAL;
   MODEL LSTIME= BCSCORE PINDEX EFTEST LFTEST / selection=stepwise details;
run;