Hello Drs. Colosimo and Harrell,
 
Thank you for your replies to my question. From Dr. Colosimo, I was able to determine that the SAS results can be replicated by adding the option conf.type="log-log" to my code as in :
 
survobj <- survfit(survfrm, conf.type="log-log", data=Survival)
 
Originally, it looked like the SAS results could be replicated using conf.type="plain". Applying this option to my actual data revealed that this was not the case, however. 
 
>From Dr. Harrell, I learned that using conf.type="log-log" may not be such a good idea. Interestingly though, I've seen at least one instance where experts in the R community use this option in their book. The book is about 10 years old. So maybe opinion about the use of this option has shifted since then. 
 
Thanks,
 
Paul  
 
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