Читать книгу Evidence in Medicine - Iain K. Crombie - Страница 19

Meta‐research studies have shown that the randomisation process is often flawed. For many trials the method is not described, is poorly described, or is well described but clearly inadequate [3–5]. An evaluation of 2 groups of trials, comprising 1,376 and 984 studies, found that 39.6% and 52.2% had flawed or poorly reported methods for generating the randomisation sequence [6].

The recommended method of randomising patients is by computer‐generated random numbers. Other techniques, such as allocation by day of admission to hospital or by even or odd dates of birth, have been used, but are thought to be unreliable. Careful reviews of large series of trials have shown that poor quality and inadequately described methods of generating the randomisation sequence commonly exaggerate the apparent benefit of treatment [4, 7].