The LIFETEST Procedure
- Product-Limit Survival Estimates
- Breslow Survival Estimates
- Fleming-Harrington Survival Estimates
- Quartile Estimates
- Mean Estimate
- Life-Table Survival Estimates
- Summary of the Number of Censored and Uncensored Values
- Rank Statistics
- Covariance Matrix for the Log-Rank Statistics
- Covariance Matrix for the Wilcoxon Statistics
- Covariance Matrix for the Tarone Statistics
- Covariance Matrix for the Peto Statistics
- Covariance Matrix for the ModPeto Statistics
- Covariance Matrix for the Fleming Statistics
- Test of Equality over Strata
- Stratified Test of Equality over Group
- Scores for Trend Test
- Trend Tests
- Adjustment for Multiple Comparisons for the Log-Rank Test
- Adjustment for Multiple Comparisons for the Wilcoxon Test
- Adjustment for Multiple Comparisons for the Tarone Test
- Adjustment for Multiple Comparisons for the Peto Test
- Adjustment for Multiple Comparisons for the ModPeto Test
- Adjustment for Multiple Comparisons for the Fleming Test
- Univariate Chi-Squares for the Log-Rank Test
- Covariance Matrix of the Log-Rank Statistics
- Forward Stepwise Sequence of Chi-Squares for the Log-Rank Test
- Univariate Chi-Squares for the Wilcoxon Test
- Covariance Matrix of the Wilcoxon Statistics
- Forward Stepwise Sequence of Chi-Squares for the Wilcoxon Test
If you use the NOPRINT option in the PROC LIFETEST statement, the procedure does not display any output.
The “Product-Limit Survival Estimates” table is displayed if you request the product-limit method of estimation. The table displays the following:
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the observed (event or censored) time
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the number of units at risk (if you specify the ATRISK option in the PROC LIFETEST statement)
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the number of events (if you specify the ATRISK option in the PROC LIFETEST statement)
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the product-limit estimate of the survivor function
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the corresponding estimate of the cumulative distribution function of the failure time
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the standard error estimate of the survivor function estimator
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the Nelson-Aalen cumulative hazard function estimate (if the NELSON option is specified in the PROC LIFETEST statement)
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the standard error of the Nelson-Aalen estimator (if the NELSON option is specified in the PROC LIFETEST statement)
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the number of event times that have been observed
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the number of event or censored times that remain to be observed
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the frequency of the observed times (if you specify the FREQ statement)
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values of the ID variables (if you specify the ID statement)
The ODS name of this table is ProductLimitEstimates.
The “Breslow Survival Estimates” table is displayed if you request the Breslow method of estimation. The table displays the following:
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the observed (event or censored) time
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the number of units at risk (if you specify the ATRISK option in the PROC LIFETEST statement)
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the number of events (if you specify the ATRISK option in the PROC LIFETEST statement)
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the Breslow estimate of the survivor function
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the corresponding estimate of the cumulative distribution function of the failure time
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the standard error estimate of the survivor function estimator
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the Nelson-Aalen cumulative hazard function estimate (if the NELSON option is specified in the PROC LIFETEST statement)
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the standard error of the Nelson-Aalen estimator (if the NELSON option is specified in the PROC LIFETEST statement)
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the number of event times that have been observed
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the number of event or censored times that remain to be observed
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the frequency of the observed times (if you specify the FREQ statement)
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values of the ID variables (if you specify the ID statement)
The ODS name of this table is BreslowEstimates.
The “Fleming-Harrington Survival Estimates” table is displayed if you request the Fleming-Harrington method of estimation. The table displays the following:
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the observed (event or censored) time
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the number of units at risk (if you specify the ATRISK option in the PROC LIFETEST statement)
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the number of events (if you specify the ATRISK option in the PROC LIFETEST statement)
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the Fleming-Harrington estimate of the survivor function
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the corresponding estimate of the cumulative distribution function of the failure time
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the standard error estimate of the survivor function estimator
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the Nelson-Aalen cumulative hazard function estimate (if the NELSON option is specified in the PROC LIFETEST statement)
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the standard error of the Nelson-Aalen estimator (if the NELSON option is specified in the PROC LIFETEST statement)
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the number of event times that have been observed
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the number of event or censored times that remain to be observed
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the frequency of the observed times (if you specify the FREQ statement)
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values of the ID variables (if you specify the ID statement)
The ODS name of this table is FlemingEstimates.
The “Quartiles Estimates” table is displayed if you request the product-limit, Breslow, or Fleming-Harrington method of estimation. The table displays the following:
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point estimates of the quartiles of the survival times
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the lower and upper confidence limits for the quartiles
The ODS name of this table is Quartiles.
The “Mean Estimate” table is displayed if you request the product-limit, Breslow, or Fleming-Harrington method of estimation. The table displays the following:
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the estimated mean survival time
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the estimated standard error of the mean estimator
The ODS name of this table is Means.
The “Life-Table Survival Estimates” table is displayed if you request the life-table method of estimation. The table displays the following:
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the time intervals into which the failure and censored times are distributed. Each interval is from the lower limit, up to but not including the upper limit; if the upper limit is infinity, the missing value is printed.
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the number of events that occur in the interval
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the number of censored observations that fall into the interval
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the effective sample size for the interval
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the estimate of conditional probability of events (failures) in the interval
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the standard error of the conditional probability estimator
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the estimate of the survival function at the beginning of the interval
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the estimate of the cumulative distribution function of the failure time at the beginning of the interval
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the standard error estimate of the survivor function estimator
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the estimate of the median residual lifetime, which is the amount of time elapsed before reducing the number of at-risk units to one-half. This is also known as the median future lifetime in Elandt-Johnson and Johnson (1980)).
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the estimated standard error of the median residual lifetime estimator
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the density function estimated at the midpoint of the interval
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the standard error estimate of the density estimator
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the hazard rate estimated at the midpoint of the interval
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the standard error estimate of the hazard estimator
The ODS name of this table is LifetableEstimates.
The “Summary of the Number of Censored and Uncensored Values” table displays following:
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the stratum identification (if the STRATA statement is specified)
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the total number of observations
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the number of event observations
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the number of censored observations
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the percentage of censored observations
The ODS name of this table is CensoredSummary.
The “Rank Statistics” table contains the test statistics of the nonparametric k-sample tests. The ODS name of this table is HomStats.
The “Covariance Matrix for the Log-Rank Statistics” table is displayed if the log-rank k-sample test is requested. The ODS name of this table is LogrankHomCov.
The “Covariance Matrix for the Wilcoxon Statistics” table is displayed if the Wilcoxon k-sample test is requested. The ODS name of this table is WilHomCov.
The “Covariance Matrix for the Tarone Statistics” table is displayed if the Tarone-Ware k-sample test is requested. The ODS name of this table is TaroneHomCov.
The “Covariance Matrix for the Peto Statistics” table is displayed if the Peto-Peto k-sample test is requested. The ODS name of this table is PetoHomCov.
The “Covariance Matrix for the ModPeto Statistics” table is displayed if the modified Peto-Peto k-sample test is requested. The ODS name of this table is ModPetoHomCov.
The “Covariance Matrix for the Fleming Statistics” table is displayed if the Fleming-Harrington k-sample test is requested. The ODS name of this table is FlemingHomCov.
The “Test of Equality over Strata” table is displayed if an unstratified k-sample test is carried out. The table contains the chi-square statistics, degrees of freedom, and p-values of the nonparametric tests and the likelihood ratio test (which is based on the exponential distribution). The ODS name of this table is HomTests.
The “Stratified Test of Equality over Group” table is displayed if a stratified test is carried out. The tables contains the chi-square statistics, degrees of freedom, and p-values of the stratified tests. The ODS name of this table is HomTests.
The “Scores for Trend Test” table is displayed if the TREND option is specified in the STRATA statement. The table contains the set of scores used to construct the trend tests. The ODS name of this table is TrendScores.
The “Trend Tests” table is displayed if the TREND option is specified in the STRATA statement. The table contains the results of the trend tests. The ODS name of this table is TrendTests.
The “Adjustment for Multiple Comparisons for the Log-Rank Test” table is displayed if the log-rank test and a multiple-comparison adjustment method are specified. The table contains the chi-square statistics and the raw and adjusted p-values of the paired comparisons. The ODS name of this table is SurvDiff.
The “Adjustment for Multiple Comparisons for the Wilcoxon Test” table is displayed if the Wilcoxon test and a multiple-comparison method are specified. The table contains the chi-square statistics and the raw and adjusted p-values of the paired comparisons. The ODS name of this table is SurvDiff.
The “Adjustment for Multiple Comparisons for the Tarone Test” table is displayed if the Tarone-Ware test and a multiple-comparison method are specified. The table contains the chi-square statistics and the raw and adjusted p-values of the paired comparisons. The ODS name of this table is SurvDiff.
The “Adjustment for Multiple Comparisons for the Peto Test” table is displayed if the Peto-Peto test and a multiple-comparison method are specified. The table contains the chi-square statistics and the raw and adjusted p-values of the paired comparisons. The ODS name of this table is SurvDiff.
The “Adjustment for Multiple Comparisons for the ModPeto Test” table is displayed if the modified Peto-Peto test and a multiple-comparison method are specified. The table contains the chi-square statistics and the raw and adjusted p-values of the paired comparisons. The ODS name of this table is SurvDiff.
The “Adjustment for Multiple Comparisons for the Fleming Test” table is displayed if the Fleming-Harrington test and a multiple-comparison method are specified. The table contains the chi-square statistics and the raw and adjusted p-values of the paired comparisons. The ODS name of this table is SurvDiff.
The “Univariate Chi-Squares for the Log-Rank Test” table is displayed if the TEST statement is specified. The table displays the log-rank test results for individual variables in the TEST statement. The ODS name of this table is LogUniChiSq.
The “Covariance Matrix of the Log-Rank Statistics” table is displayed if the TEST statement is specified. The table displays the estimated covariance matrix of the log-rank statistics for association. The ODS name of this table is LogTestCov.
The “Forward Stepwise Sequence of Chi-Squares for the Log-Rank Test” table is displayed if the TEST statement is specified. The table contains the sequence of partial chi-square statistics for the log-rank test in the order of the greatest increase to the overall test statistic, the degrees of freedom of the partial chi-square statistics, the approximate probability values of the partial chi-square statistics, the chi-square increments for including the given variables, and the probability values of the chi-square increments. The ODS name of this table is LogForStepSeq.
The “Univariate Chi-Squares for the Wilcoxon Test” table displays the Wilcoxon test results for individual variables in the TEST statement. The ODS name of this table is WilUniChiSq.
The “Covariance Matrix of the Wilcoxon Statistics” table is displayed if the TEST statement is specified. The table displays the estimated covariance matrix of the Wilcoxon statistics for association. The ODS name of this table is WilTestCov.
The “Forward Stepwise Sequence of Chi-Squares for the Wilcoxon Test” table is displayed if the TEST statement is specified. The table contains the sequence of partial chi-square statistics for the Wilcoxon test in the order of the greatest increase to the overall test statistic, the degrees of freedom of the partial chi-square statistics, the approximate probability values of the partial chi-square statistics, the chi-square increments for including the given variables, and the probability values of the chi-square increments. The ODS name of this table is WilForStepSeq.