Clin Orthop Surg.  2014 Mar;6(1):103-109. 10.4055/cios.2014.6.1.103.

How to Do Random Allocation (Randomization)

• Kim J
• Shin W

• KMID: 1737639
• DOI: http://doi.org/10.4055/cios.2014.6.1.103

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.

Keyword

Random allocation; Simple randomization; Block randomization; Stratified randomization

MeSH Terms

Humans
Random Allocation
Randomized Controlled Trials as Topic/*methods

Figure

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  Fig. 1 Simple randomization sheet.

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  Fig. 2 An example of randomization when the block size is four.

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  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.

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  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.

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  Fig. 5 The reality of the randomization procedure.

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  Fig. 6 MS word can replace A and B with a specific treatment name easily.

Reference

1. Bhandari M, Richards RR, Sprague S, Schemitsch EH. The quality of reporting of randomized trials in the Journal of Bone and Joint Surgery from 1988 through 2000. J Bone Joint Surg Am. 2002; 84(3):388–396.

2. Montané E, Vallano A, Vidal X, Aguilera C, Laporte JR. Reporting randomised clinical trials of analgesics after traumatic or orthopaedic surgery is inadequate: a systematic review. BMC Clin Pharmacol. 2010; 10:2.