How to do random allocation (randomization)

Abstract

Purpose: To explain the concept and procedure of random allocation as used in a randomized controlled study.

Methods: We explain the general concept of random allocation and demonstrate how to perform the procedure easily and how to report it in a paper.

Keywords: Block randomization; Random allocation; Simple randomization; Stratified randomization.

Conflict of interest statement

No potential conflict of interest relevant to this article was reported.

Figures

Fig. 1

Simple randomization sheet.

Fig. 2

An example of randomization when the block size is four.

Fig. 3

Block randomization when the block size is two and four. Total eight blocks in the red-dotted line are assigned at random. The left column is for allocation and the right column is for the total sample size.

Fig. 4

www.randomization.com can do block randomization more easily. In this figure, the block size is 2, 4, and 6 when the total samples are 88.

Fig. 5

The reality of the randomization procedure.

Fig. 6

MS word can replace A and B with a specific treatment name easily.