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Problem Note 64137: If there is more than one censored observation at time zero in PROC LIFETEST, the at-risk value at T=0 is incorrect

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If you have a failure time variable T in the TIME statement in PROC LIFETEST and the following conditions are met, the At Risk value at T=0 in the survival plot is incorrect:

  • T has more than one censored observation at time zero, and
  • you specify the PLOTS=SURVIVAL(ATRISK) option in the PROC LIFETEST statement, or
  • you specify the PLOTS=SURVIVAL(ATRISK=number-list) option including 0 in the list

If you also include the ATRISK option in the PROC LIFETEST statement, the Number at Risk in the Product-Limit Survival Estimates table is incorrect in the last T=0.00* row.

As a workaround, you can add a near-zero value, such as 1e-10, to T for the observations where T=0.

Click the Hot Fix tab in this note to access the hot fix for this issue.



Operating System and Release Information

Product FamilyProductSystemProduct ReleaseSAS Release
ReportedFixed*ReportedFixed*
SAS SystemSAS/STATz/OS15.19.4 TS1M6
Microsoft® Windows® for x6415.19.4 TS1M6
Microsoft Windows 8 Enterprise 32-bit15.19.4 TS1M6
Microsoft Windows 8 Enterprise x6415.19.4 TS1M6
Microsoft Windows 8 Pro 32-bit15.19.4 TS1M6
Microsoft Windows 8 Pro x6415.19.4 TS1M6
Microsoft Windows 8.1 Enterprise 32-bit15.19.4 TS1M6
Microsoft Windows 8.1 Enterprise x6415.19.4 TS1M6
Microsoft Windows 8.1 Pro 32-bit15.19.4 TS1M6
Microsoft Windows 8.1 Pro x6415.19.4 TS1M6
Microsoft Windows 1015.19.4 TS1M6
Microsoft Windows Server 2012 Datacenter15.19.4 TS1M6
Microsoft Windows Server 2012 R2 Datacenter15.19.4 TS1M6
Microsoft Windows Server 2012 R2 Std15.19.4 TS1M6
Microsoft Windows Server 2012 Std15.19.4 TS1M6
Microsoft Windows Server 201615.19.4 TS1M6
Microsoft Windows Server 201915.19.4 TS1M6
Windows 7 Enterprise 32 bit15.19.4 TS1M6
Windows 7 Enterprise x6415.19.4 TS1M6
Windows 7 Home Premium 32 bit15.19.4 TS1M6
Windows 7 Home Premium x6415.19.4 TS1M6
Windows 7 Professional 32 bit15.19.4 TS1M6
Windows 7 Professional x6415.19.4 TS1M6
Windows 7 Ultimate 32 bit15.19.4 TS1M6
Windows 7 Ultimate x6415.19.4 TS1M6
64-bit Enabled AIX15.19.4 TS1M6
64-bit Enabled Solaris15.19.4 TS1M6
HP-UX IPF15.19.4 TS1M6
Linux for x6415.19.4 TS1M6
Solaris for x6415.19.4 TS1M6
* For software releases that are not yet generally available, the Fixed Release is the software release in which the problem is planned to be fixed.