Creating a Randomization List

Creating a Randomization List for a Simple Study

This option is for simple designs with 2 to 20 treatments/groups to which subjects must be assigned. Use this option if:

• the sample sizes in all the groups will be equal
• all subjects are from a single center
• there are no strata.

If different treatment groups will have different sample sizes, if there are multiple centers or strata, or if you wish to choose your own block sizes, or have greater control over subject ID, select Create Randomization List (Advanced) or Create Randomization List (Complex Designs) instead.

Suppose your planned study will have two treatment groups, New drug and Placebo, with 20 subjects per group for a total of 40 subjects.

The pharmacist will need a list of patient ID numbers together with the treatment group to which each patient will be assigned in order to make up 40 bottles of pills. Each bottle will be labelled only with the patient ID and dispensing information, to maintain a double-blind study.

You will see the original screen again. The required sample size is 40, so type this in (or type in a somewhat larger number if you may need a few extra patient assignments just in case).

Click on the View List button. nQuery Advissor will create a randomization list using its own algorithm for mixing randomization block sizes.

For this example, block sizes will be 2 and 4.

The randomization list dialog box will appear with the study title, date, and a viewable spreadsheet with subject ID numbers and the treatment or group assignment for each subject.

You can examine the list on the screen by moving up and down using the slider bar. You can save the list to a file, you can copy it and paste it into a document or a spreadsheet, or you can print it. If you wish to change the specifications, click on re-specify and change the group names or the sample size. If you want to keep this list, you must save it before clicking on the re-specify button.

To print the randomization list file:

Click on Print.

To save the list to a file:

Click on Save or Save as. The file will be saved as an nQuery Advisor file with the nQuery Advisor randomization list file extension .nqr. You can open this file again at a later time. In addition, you can save the header information and the treatment assignment list in a comma delimited text file (.csv file) or an ordinary text file (.txt file).

To copy the file for inclusion in documents:

Click on Copy. The list can be pasted directly into a spreadsheet or word processing document where it will appear as a table. Information about the study title, treatment names, sample size, and blocking method will appear in the pasted table. You can then edit the information at the top of the page and the column headers and/or subject ID numbers as desired and save or print from these programs.

Text on the left shows how the list will appear when pasted into a word processing document from nQuery Advisor.
If you want to create labels for sealed randomization envelopes, you can paste the file into Word and then use the Word Mail Merge Wizard. (See details in Example 3, Chapter 6 of the nQuery Advisor 7 manual.)