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 Family | Product | System | Product Release | SAS Release | ||
| Reported | Fixed* | Reported | Fixed* | |||
| SAS System | SAS/STAT | z/OS | 15.1 | 9.4 TS1M6 | ||
| Microsoft® Windows® for x64 | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8 Enterprise 32-bit | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8 Enterprise x64 | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8 Pro 32-bit | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8 Pro x64 | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8.1 Enterprise 32-bit | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8.1 Enterprise x64 | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8.1 Pro 32-bit | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 8.1 Pro x64 | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows 10 | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows Server 2012 Datacenter | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows Server 2012 R2 Datacenter | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows Server 2012 R2 Std | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows Server 2012 Std | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows Server 2016 | 15.1 | 9.4 TS1M6 | ||||
| Microsoft Windows Server 2019 | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Enterprise 32 bit | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Enterprise x64 | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Home Premium 32 bit | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Home Premium x64 | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Professional 32 bit | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Professional x64 | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Ultimate 32 bit | 15.1 | 9.4 TS1M6 | ||||
| Windows 7 Ultimate x64 | 15.1 | 9.4 TS1M6 | ||||
| 64-bit Enabled AIX | 15.1 | 9.4 TS1M6 | ||||
| 64-bit Enabled Solaris | 15.1 | 9.4 TS1M6 | ||||
| HP-UX IPF | 15.1 | 9.4 TS1M6 | ||||
| Linux for x64 | 15.1 | 9.4 TS1M6 | ||||
| Solaris for x64 | 15.1 | 9.4 TS1M6 | ||||
A fix for this issue for SAS/STAT 15.1 is available at:
https://tshf.sas.com/techsup/download/hotfix/HF2/E8U.html#64137
If the failure time variable T in the TIME statement in PROC LIFETEST has more than one censored observation at time zero, the at-risk value at T=0 is incorrect.
| Type: | Problem Note |
| Priority: | medium |
| Topic: | SAS Reference ==> Procedures ==> LIFETEST |
| Date Modified: | 2019-05-20 13:36:21 |
| Date Created: | 2019-04-30 13:41:08 |