Call: survfit(formula = Surv(futime, fustat) ~ risk, data = rt)

                risk=high 
   time n.risk n.event survival std.err lower 95% CI upper 95% CI
 0.0301    152       1    0.993 0.00656        0.981        1.000
 0.0384    150       1    0.987 0.00927        0.969        1.000
 0.0630    148       1    0.980 0.01136        0.958        1.000
 0.1534    147       1    0.973 0.01309        0.948        0.999
 0.1753    145       1    0.967 0.01462        0.939        0.996
 0.1890    144       1    0.960 0.01599        0.929        0.992
 0.2082    143       1    0.953 0.01723        0.920        0.988
 0.2247    142       1    0.947 0.01837        0.911        0.983
 0.2356    141       1    0.940 0.01943        0.903        0.979
 0.2438    140       1    0.933 0.02041        0.894        0.974
 0.2603    139       1    0.926 0.02134        0.886        0.969
 0.2932    138       1    0.920 0.02222        0.877        0.964
 0.3068    136       1    0.913 0.02306        0.869        0.959
 0.3534    134       2    0.899 0.02465        0.852        0.949
 0.3890    132       1    0.893 0.02539        0.844        0.944
 0.3945    131       1    0.886 0.02609        0.836        0.938
 0.4137    130       1    0.879 0.02676        0.828        0.933
 0.4548    129       1    0.872 0.02741        0.820        0.928
 0.4740    128       1    0.865 0.02803        0.812        0.922
 0.4986    127       1    0.858 0.02863        0.804        0.916
 0.5068    126       1    0.852 0.02920        0.796        0.911
 0.5397    125       1    0.845 0.02975        0.789        0.905
 0.5945    124       1    0.838 0.03028        0.781        0.900
 0.5973    123       1    0.831 0.03079        0.773        0.894
 0.6082    122       1    0.824 0.03128        0.765        0.888
 0.6658    121       1    0.818 0.03176        0.758        0.882
 0.7014    120       1    0.811 0.03222        0.750        0.876
 0.7096    119       1    0.804 0.03266        0.742        0.871
 0.7342    118       1    0.797 0.03308        0.735        0.865
 0.7507    117       1    0.790 0.03350        0.727        0.859
 0.7644    116       1    0.784 0.03389        0.720        0.853
 0.7726    115       1    0.777 0.03428        0.712        0.847
 0.7753    114       1    0.770 0.03465        0.705        0.841
 0.8000    113       1    0.763 0.03500        0.697        0.835
 0.8055    112       1    0.756 0.03535        0.690        0.829
 0.8685    111       2    0.743 0.03600        0.675        0.817
 0.8959    109       1    0.736 0.03631        0.668        0.811
 0.9041    108       1    0.729 0.03661        0.661        0.804
 0.9233    107       1    0.722 0.03689        0.653        0.798
 0.9644    106       1    0.715 0.03717        0.646        0.792
 0.9671    105       1    0.709 0.03743        0.639        0.786
 0.9890    102       1    0.702 0.03771        0.632        0.780
 1.0027    101       1    0.695 0.03797        0.624        0.773
 1.0329     99       1    0.688 0.03823        0.617        0.767
 1.0384     97       1    0.681 0.03848        0.609        0.760
 1.0548     95       2    0.666 0.03898        0.594        0.747
 1.0603     93       1    0.659 0.03922        0.587        0.741
 1.0767     91       1    0.652 0.03945        0.579        0.734
 1.0822     90       1    0.645 0.03967        0.571        0.727
 1.1041     89       1    0.637 0.03988        0.564        0.721
 1.1123     88       1    0.630 0.04008        0.556        0.714
 1.1151     87       1    0.623 0.04027        0.549        0.707
 1.1699     85       1    0.616 0.04046        0.541        0.700
 1.1781     84       1    0.608 0.04063        0.534        0.693
 1.2493     83       1    0.601 0.04080        0.526        0.686
 1.2658     80       1    0.593 0.04097        0.518        0.679
 1.3123     78       1    0.586 0.04115        0.510        0.672
 1.3342     77       1    0.578 0.04131        0.503        0.665
 1.3507     75       1    0.570 0.04147        0.495        0.658
 1.4521     73       1    0.563 0.04164        0.487        0.650
 1.4932     71       1    0.555 0.04180        0.479        0.643
 1.4959     70       1    0.547 0.04194        0.470        0.636
 1.5014     69       1    0.539 0.04208        0.462        0.628
 1.5671     67       1    0.531 0.04221        0.454        0.620
 1.5808     65       1    0.523 0.04235        0.446        0.613
 1.5890     63       1    0.514 0.04248        0.438        0.605
 1.6000     62       1    0.506 0.04260        0.429        0.597
 1.7096     61       1    0.498 0.04270        0.421        0.589
 1.7123     59       1    0.489 0.04280        0.412        0.581
 1.7288     58       1    0.481 0.04288        0.404        0.573
 1.8247     54       1    0.472 0.04301        0.395        0.564
 1.9918     51       1    0.463 0.04315        0.385        0.556
 2.0247     50       1    0.453 0.04326        0.376        0.547
 2.0904     49       1    0.444 0.04336        0.367        0.538
 2.1178     47       1    0.435 0.04346        0.357        0.529
 2.2986     42       1    0.424 0.04364        0.347        0.519
 2.3370     41       1    0.414 0.04378        0.337        0.509
 2.5068     38       1    0.403 0.04397        0.326        0.499
 2.5397     37       1    0.392 0.04411        0.315        0.489
 2.6986     34       1    0.381 0.04429        0.303        0.478
 2.7342     33       1    0.369 0.04443        0.292        0.467
 2.9562     30       1    0.357 0.04462        0.279        0.456
 2.9616     29       1    0.345 0.04475        0.267        0.444
 2.9945     28       1    0.332 0.04481        0.255        0.433
 3.5315     22       1    0.317 0.04525        0.240        0.420
 3.9973     18       1    0.300 0.04604        0.222        0.405
 4.5781     11       1    0.272 0.04925        0.191        0.388
 5.4849      7       1    0.233 0.05549        0.146        0.372
 7.0411      1       1    0.000     NaN           NA           NA

                risk=low 
    time n.risk n.event survival std.err lower 95% CI upper 95% CI
  0.0877    152       1    0.993 0.00656       0.9807        1.000
  0.1699    151       1    0.987 0.00924       0.9689        1.000
  0.1781    150       1    0.980 0.01128       0.9584        1.000
  0.3945    147       1    0.974 0.01303       0.9484        0.999
  0.5233    146       1    0.967 0.01455       0.9388        0.996
  0.5315    145       2    0.954 0.01713       0.9206        0.988
  0.5425    143       1    0.947 0.01826       0.9118        0.983
  0.5616    142       1    0.940 0.01931       0.9031        0.979
  0.5726    141       1    0.934 0.02030       0.8946        0.974
  0.5890    139       1    0.927 0.02123       0.8862        0.969
  0.7151    134       1    0.920 0.02217       0.8775        0.964
  0.7781    132       1    0.913 0.02307       0.8689        0.959
  0.8959    130       1    0.906 0.02394       0.8602        0.954
  0.9151    129       1    0.899 0.02476       0.8517        0.949
  0.9342    128       1    0.892 0.02555       0.8432        0.943
  0.9370    127       1    0.885 0.02629       0.8348        0.938
  0.9781    126       1    0.878 0.02701       0.8265        0.932
  1.0521    124       1    0.871 0.02770       0.8182        0.927
  1.0822    120       1    0.864 0.02840       0.8096        0.921
  1.0877    119       1    0.856 0.02908       0.8011        0.915
  1.1041    117       1    0.849 0.02974       0.7926        0.909
  1.1342    115       1    0.842 0.03038       0.7841        0.903
  1.2301    111       1    0.834 0.03104       0.7753        0.897
  1.2712    110       1    0.826 0.03167       0.7666        0.891
  1.5342    108       1    0.819 0.03229       0.7579        0.885
  1.6603    104       1    0.811 0.03292       0.7489        0.878
  1.7918     95       1    0.802 0.03366       0.7390        0.871
  1.8630     92       1    0.794 0.03441       0.7290        0.864
  2.2027     78       1    0.783 0.03544       0.7170        0.856
  2.3616     74       1    0.773 0.03651       0.7045        0.848
  2.4164     73       1    0.762 0.03751       0.6922        0.839
  2.7205     64       1    0.750 0.03877       0.6781        0.830
  2.9863     55       1    0.737 0.04039       0.6617        0.820
  3.1041     54       1    0.723 0.04189       0.6455        0.810
  3.1068     53       1    0.709 0.04326       0.6295        0.800
  3.2932     48       1    0.695 0.04481       0.6122        0.788
  4.1205     34       1    0.674 0.04793       0.5865        0.775
  4.3589     30       1    0.652 0.05133       0.5585        0.761
  4.4959     28       1    0.628 0.05452       0.5302        0.745
  4.7068     26       1    0.604 0.05753       0.5014        0.728
  5.9342     18       1    0.571 0.06338       0.4591        0.710
  7.4438     13       1    0.527 0.07212       0.4028        0.689
  7.5096     11       1    0.479 0.07990       0.3454        0.664
  8.3808     10       1    0.431 0.08506       0.2928        0.635
 12.8219      6       1    0.359 0.09657       0.2121        0.608
 13.0411      5       1    0.287 0.10049       0.1448        0.570
 13.3041      4       1    0.216 0.09773       0.0886        0.524
 14.1151      3       1    0.144 0.08767       0.0435        0.475