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Stata Textbook Examples
Applied Survival Analysis by Hosmer and Lemeshow
Chapter 2: Descriptive Methods for Survival Data

The data files used for the examples in this text can be downloaded in a zip file from the Wiley FTP website or the Stata Web site.  You can then use a program such as WinZip to unzip the data files.  If you need assistance getting data into Stata, please see our Stata Class Notes, especially the unit on Entering Data.  (NOTE:  The *.dat files are the data files, and the *.txt files contain the codebook information.)
Table 2.1, page 28.
input subj time censor
1  5 1
2  6 0
3  8 1
4  3 1
5 22 1
end

list

         subj      time    censor
  1.        1         5         1
  2.        2         6         0
  3.        3         8         1
  4.        4         3         1
  5.        5        22         1
Table 2.2, page 32.
stset time, failure(censor)
sts list, at(0 3 5 6 8 22)

         failure _d:  censor
   analysis time _t:  time

              Beg.                      Survivor      Std.
    Time     Total     Fail             Function     Error     [95% Conf. Int.]
-------------------------------------------------------------------------------
       0         0        0              1.0000         .          .         .
       3         5        1              0.8000    0.1789     0.2038    0.9692
       5         4        1              0.6000    0.2191     0.1257    0.8818
       6         3        0              0.6000    0.2191     0.1257    0.8818
       8         2        1              0.3000    0.2387     0.0123    0.7192
      22         1        1              0.0000         .          .         .
-------------------------------------------------------------------------------
Note:  Survivor function is calculated over full data and evaluated at
       indicated times; it is not calculated from aggregates shown at left.
Figure 2.2, page 32.
sts graph, censored(single) ylabel(0(.2)1) xlabel(0(5)25)
Figure 2.2, page 34.
use hmohiv, clear
stset time, failure(censor)

sts graph, censored(single) ylabel(0(.2)1) xlabel(0(10)60)
Parts of Table 2.3, page 35.
sts list

         failure _d:  censor
   analysis time _t:  time

           Beg.          Net            Survivor      Std.
  Time    Total   Fail   Lost           Function     Error     [95% Conf. Int.]
-------------------------------------------------------------------------------
     1      100     15      2             0.8500    0.0357     0.7636    0.9067
     2       83      5      5             0.7988    0.0402     0.7057    0.8652
     3       73     10      2             0.6894    0.0473     0.5862    0.7718
     4       61      4      1             0.6442    0.0493     0.5387    0.7315
     5       56      7      0             0.5636    0.0517     0.4564    0.6577
     6       49      2      1             0.5406    0.0521     0.4334    0.6361
     7       46      6      1             0.4701    0.0526     0.3644    0.5688
     8       39      4      0             0.4219    0.0525     0.3183    0.5217
     9       35      3      0             0.3857    0.0520     0.2845    0.4858
    10       32      3      1             0.3496    0.0511     0.2514    0.4493
    11       28      3      0             0.3121    0.0500     0.2177    0.4110
    12       25      2      2             0.2872    0.0490     0.1956    0.3851
    13       21      1      0             0.2735    0.0486     0.1835    0.3711
    14       20      1      0             0.2598    0.0480     0.1715    0.3569
    15       19      2      0             0.2325    0.0467     0.1479    0.3282
    19       17      0      1             0.2325    0.0467     0.1479    0.3282
    22       16      1      0             0.2179    0.0460     0.1355    0.3130
    24       15      0      1             0.2179    0.0460     0.1355    0.3130
    30       14      1      0             0.2024    0.0453     0.1222    0.2969
    31       13      1      0             0.1868    0.0444     0.1092    0.2805
    32       12      1      0             0.1712    0.0433     0.0966    0.2638
    34       11      1      0             0.1557    0.0421     0.0843    0.2469
    35       10      1      0             0.1401    0.0407     0.0724    0.2296
    36        9      1      0             0.1245    0.0390     0.0610    0.2119
    43        8      1      0             0.1090    0.0371     0.0500    0.1939
    53        7      1      0             0.0934    0.0349     0.0396    0.1754
    54        6      1      0             0.0778    0.0324     0.0298    0.1564
    56        5      0      1             0.0778    0.0324     0.0298    0.1564
    57        4      1      0             0.0584    0.0296     0.0178    0.1349
    58        3      1      0             0.0389    0.0253     0.0082    0.1117
    60        2      0      2             0.0389    0.0253     0.0082    0.1117
-------------------------------------------------------------------------------
Table 2.4, page 38 and Figure 2.5, page 39.
ltable time censor, interval(6) graph noconf xlab(0(20)80) ylab(0 .5 1)

                 Beg.                                 Std.
   Interval     Total   Deaths   Lost    Survival    Error     [95% Conf. Int.]
-------------------------------------------------------------------------------
    0     6       100       41     10     0.5684    0.0508     0.4629    0.6608
    6    12        49       21      3     0.3171    0.0498     0.2228    0.4154
   12    18        25        6      2     0.2378    0.0467     0.1530    0.3334
   18    24        17        1      1     0.2234    0.0460     0.1405    0.3184
   24    30        15        0      1     0.2234    0.0460     0.1405    0.3184
   30    36        14        5      0     0.1436    0.0412     0.0749    0.2339
   36    42         9        1      0     0.1277    0.0396     0.0630    0.2160
   42    48         8        1      0     0.1117    0.0377     0.0516    0.1977
   48    54         7        1      0     0.0958    0.0355     0.0408    0.1790
   54    60         6        3      1     0.0435    0.0260     0.0106    0.1155
   60    66         2        0      2     0.0435    0.0260     0.0106    0.1155
-------------------------------------------------------------------------------
Figure 2.3, page 38.
generate t6 = recode(time,0,5,11,17,23,29,35,41,47,53,59,65)
stset t6, failure(censor)

sts graph, ylabel(0 .5 1)
Parts of Figure 2.5, page 46.
Note: Does not include Hall and Wellner confidence bands.
stset time, failure(censor)

sts graph, gwood ylabel(0(.2)1) xlabel(0(10)60)
Parts of Table 2.5, page 50.
stsum

         |               incidence       no. of    |------ Survival time -----|
         | time at risk     rate        subjects        25%       50%       75%
---------+---------------------------------------------------------------------
   total |         1136   .0704225           100          3         7        15

stci, dd(2)

             |    no. of 
             |  subjects         50%     Std. Err.     [95% Conf. Interval]
-------------+-------------------------------------------------------------
       total |       100        7.00          1.11            5          9

stci,dd(2) p(25)

             |    no. of 
             |  subjects         25%     Std. Err.     [95% Conf. Interval]
-------------+-------------------------------------------------------------
       total |       100        3.00          0.59            2          4

stci,dd(2) p(75)

             |    no. of 
             |  subjects         75%     Std. Err.     [95% Conf. Interval]
-------------+-------------------------------------------------------------
       total |       100       15.00          7.45           11         34
Table 2.6, page 52.
Note: There is an error in the book, the upper bound on the first line is incorrect.
sts list, at(4 5 to 9)

              Beg.                      Survivor      Std.
    Time     Total     Fail             Function     Error     [95% Conf. Int.]
-------------------------------------------------------------------------------
       4        61       34              0.6442    0.0493     0.5387    0.7315
       5        56        7              0.5636    0.0517     0.4564    0.6577
       6        49        2              0.5406    0.0521     0.4334    0.6361
       7        46        6              0.4701    0.0526     0.3644    0.5688
       8        39        4              0.4219    0.0525     0.3183    0.5217
       9        35        3              0.3857    0.0520     0.2845    0.4858
-------------------------------------------------------------------------------
Note:  Survivor function is calculated over full data and evaluated at
       indicated times; it is not calculated from aggregates shown at left.
Figure 2.7, page 58.
sts graph, by(drug) ylabel(0(.2)1) xlabel(0(10)60)
Table 2.11, page 65.
sts test drug, logrank

Log-rank test for equality of survivor functions

      |   Events         Events
drug  |  observed       expected
------+-------------------------
0     |        42          54.88
1     |        38          25.12
------+-------------------------
Total |        80          80.00

            chi2(1) =      11.86
            Pr>chi2 =     0.0006

sts test drug, w

Wilcoxon (Breslow) test for equality of survivor functions

[...table omitted...]

            chi2(1) =      10.91
            Pr>chi2 =     0.0010
            
sts test drug, tw

Tarone-Ware test for equality of survivor functions

[...table omitted...]

            chi2(1) =      12.34
            Pr>chi2 =     0.0004

sts test drug, p

Peto-Peto test for equality of survivor functions

[...table omitted...]

            chi2(1) =      11.50
            Pr>chi2 =     0.0007
Table 2.12, page 65.
generate agegrp = recode(age,29,34,39,54)

stci, by(agegrp)

             |    no. of 
agegrp       |  subjects         50%     Std. Err.     [95% Conf. Interval]
-------------+-------------------------------------------------------------
          29 |        12          43      8.095313            5          .
          34 |        34           9      .8198685            6         12
          39 |        25           7      .6573248            3          9
          54 |        29           4      .3719542            2          5
-------------+-------------------------------------------------------------
       total |       100           7      1.114345            5          9
Figure 2.8, page 69.
sts graph, by(agegrp)
Tables 2.14 and 2.15, page 70.
/* set agegrp2 to midpoint of age category */
recode agegrp 29=25 34=32.5 39=37.5 54=47.5, gen(agegrp2)

sts test agegrp2, trend

Log-rank test for equality of survivor functions

       |   Events         Events
agegrp |  observed       expected
-------+-------------------------
29     |         8          19.89
34     |        29          29.43
39     |        20          17.81
54     |        23          12.87
-------+-------------------------
Total  |        80          80.00

             chi2(3) =      19.91
             Pr>chi2 =     0.0002
             
Test for trend of survivor functions

            chi2(1) =      19.07
            Pr>chi2 =     0.0000

sts test agegrp2, trend w

Wilcoxon (Breslow) test for equality of survivor functions

[...table omitted...]

             chi2(3) =      14.14
             Pr>chi2 =     0.0027

Test for trend of survivor functions

              chi2(1) =      14.08
              Pr>chi2 =     0.0002
             
sts test agegrp2, trend tw

Tarone-Ware test for equality of survivor functions

[...table omitted...]

             chi2(3) =      16.96
             Pr>chi2 =     0.0007

Test for trend of survivor functions

              chi2(1) =      16.67
              Pr>chi2 =     0.0000

sts test agegrp2, trend p


Peto-Peto test for equality of survivor functions

[...table omitted...]

             chi2(3) =      15.67
             Pr>chi2 =     0.0013

Test for trend of survivor functions

              chi2(1) =      15.54
              Pr>chi2 =     0.0001
Table 2.17, page 76.
sts list, na


           Beg.          Net          Nelson-Aalen    Std.
  Time    Total   Fail   Lost           Cum. Haz.    Error     [95% Conf. Int.]
-------------------------------------------------------------------------------
     1      100     15      2             0.1500    0.0387     0.0904    0.2488
     2       83      5      5             0.2102    0.0472     0.1354    0.3264
     3       73     10      2             0.3472    0.0640     0.2419    0.4985
     4       61      4      1             0.4128    0.0720     0.2933    0.5809
     5       56      7      0             0.5378    0.0861     0.3930    0.7360
     6       49      2      1             0.5786    0.0908     0.4254    0.7870
     7       46      6      1             0.7091    0.1053     0.5301    0.9485
     8       39      4      0             0.8116    0.1171     0.6117    1.0768
     9       35      3      0             0.8973    0.1271     0.6798    1.1845
    10       32      3      1             0.9911    0.1382     0.7541    1.3025
    11       28      3      0             1.0982    0.1514     0.8382    1.4388
    12       25      2      2             1.1782    0.1616     0.9005    1.5416
    13       21      1      0             1.2258    0.1685     0.9364    1.6048
    14       20      1      0             1.2758    0.1757     0.9740    1.6712
    15       19      2      0             1.3811    0.1908     1.0534    1.8107
    19       17      0      1             1.3811    0.1908     1.0534    1.8107
    22       16      1      0             1.4436    0.2008     1.0991    1.8961
    24       15      0      1             1.4436    0.2008     1.0991    1.8961
    30       14      1      0             1.5150    0.2131     1.1499    1.9961
    31       13      1      0             1.5920    0.2266     1.2044    2.1042
    32       12      1      0             1.6753    0.2414     1.2630    2.2221
    34       11      1      0             1.7662    0.2580     1.3265    2.3516
    35       10      1      0             1.8662    0.2767     1.3956    2.4955
    36        9      1      0             1.9773    0.2982     1.4714    2.6572
    43        8      1      0             2.1023    0.3233     1.5552    2.8418
    53        7      1      0             2.2452    0.3535     1.6491    3.0567
    54        6      1      0             2.4118    0.3908     1.7556    3.3133
    56        5      0      1             2.4118    0.3908     1.7556    3.3133
    57        4      1      0             2.6618    0.4639     1.8916    3.7457
    58        3      1      0             2.9952    0.5712     2.0610    4.3528
    60        2      0      2             2.9952    0.5712     2.0610    4.3528
-------------------------------------------------------------------------------
Figure 2.10, page 77.
sts generate km = s
sts generate na = na
replace na = exp(-na)

graph twoway scatter km na time, s(T O) c(J J) sort ylabel(0 .5 1)
Figure 2.12, page 82.
sts generate h = h
replace h=0 if h==.

graph twoway (lowess h time, bwidth(.99)) (scatter h time), ylabel(0 .35) xlabel(1 60)

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