Free Trial

Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.

  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

Chapter 21. The Log-Rank Test > 21.4 Details & Notes

21.4 Details & Notes

21.4.1 Clinical study outcomes often have the goal of estimating response or event rates and comparing them among randomized groups. However, the selection of a time point during the clinical study at which to compare event rates is not always clear-cut. The last double-blind visit is often designated for such use, although drawbacks might exist for this choice. First, the duration of the study might be somewhat arbitrary or constrained by safety issues or other considerations unrelated to response. More importantly, the analysis ignores information prior to this evaluation time point that might have an important impact on the results.

If the data in Example 21.1 were analyzed with the chi-square test (Chapter 16) for comparing event rates at the final visit using a 'lastobservation-carried-forward' method, you obtain the summary shown in Table 21.4.


  

You are currently reading a PREVIEW of this book.

                                                                                                                    

Get instant access to over $1 million worth of books and videos.

  

Start a Free Trial


  
  • Safari Books Online
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint