Minimisation is much better than the randomised block design in certain cases

BMJ 1999;318:1420 ( 22 May )

Letters

Minimisation is much better than the randomised block design in certain cases

The first 150 words of the full text of this article appear below.

EDITOR $---$ In commenting on our editorial¹ Ross suggests that the randomised block design is similar to minimisation but haseven more power.² We are unaware of any publication which showsthat this is the case. He also states that these two methods havethe same disadvantage $---$ that assignment to a block becomes a majorundertaking. In fact, minimisation does not have the problem ofassignment to a block that the randomised block design has, andthis is precisely why minimisation wasinvented.

In the context of clinical trials the randomised block design is referred to as stratified randomisation $---$ for example, themen and women each have their own random allocation series; ifstratified randomisation is feasible it is indeed an excellentmethod for obtaining balanced treatment groups. However, stratifiedallocation becomes unwieldy and eventually impossible as the numberof relevant patient characteristics increases. Ross mentions age,sex, or number . . . [Full text of this article]