Book contents
- Frontmatter
- Contents
- Editorial board
- Acknowledgements
- List of contributors
- Introduction
- Part I
- 1 The ethics of clinical research
- 2 Research ethics committees and the law
- 3 The regulation of medical research: a historical overview
- 4 The regulation of medical research in the UK
- 5 Observational and epidemiological research
- 6 Social survey research
- 7 Approaching qualitative research
- 8 Complementary and alternative medicine: challenges for research ethics committees
- 9 The ethical review of student research in the context of the governance arrangements for research ethics committees
- 10 The ethics of genetic research
- 11 Research or audit?
- 12 Randomised controlled trials
- 13 Determining the study size
- 14 Risk assessment for research participants
- 15 Absorbed radiation in patient and volunteer studies submitted to the ethical committee: a memorandum
- 16 A guide to the use of radioactive materials and radiological procedures for research purposes
- 17 Indemnity in medical research
- 18 The prevention and management of fraud and misconduct: the role of the LREC
- 19 Understanding clinical trials: a model for providing information to potential participants
- 20 The law relating to consent
- 21 Writing information for potential research participants
- 22 The law relating to confidentiality
- 23 Research involving vulnerable participants: some ethical issues
- 24 The ethics of research related to healthcare in developing countries
- Part II
- Index
12 - Randomised controlled trials
Published online by Cambridge University Press: 08 January 2010
- Frontmatter
- Contents
- Editorial board
- Acknowledgements
- List of contributors
- Introduction
- Part I
- 1 The ethics of clinical research
- 2 Research ethics committees and the law
- 3 The regulation of medical research: a historical overview
- 4 The regulation of medical research in the UK
- 5 Observational and epidemiological research
- 6 Social survey research
- 7 Approaching qualitative research
- 8 Complementary and alternative medicine: challenges for research ethics committees
- 9 The ethical review of student research in the context of the governance arrangements for research ethics committees
- 10 The ethics of genetic research
- 11 Research or audit?
- 12 Randomised controlled trials
- 13 Determining the study size
- 14 Risk assessment for research participants
- 15 Absorbed radiation in patient and volunteer studies submitted to the ethical committee: a memorandum
- 16 A guide to the use of radioactive materials and radiological procedures for research purposes
- 17 Indemnity in medical research
- 18 The prevention and management of fraud and misconduct: the role of the LREC
- 19 Understanding clinical trials: a model for providing information to potential participants
- 20 The law relating to consent
- 21 Writing information for potential research participants
- 22 The law relating to confidentiality
- 23 Research involving vulnerable participants: some ethical issues
- 24 The ethics of research related to healthcare in developing countries
- Part II
- Index
Summary
A randomised controlled trial is the standard method for assessing a new treatment or procedure. Such trials provide a more definitive answer than observational studies about differences between groups. To assess whether a treatment is effective or not, a group of patients allocated to a new treatment is compared with a group that receives an existing treatment or placebo.
In observational studies we can only observe what happens to individuals without intervening in any way. We can never rule out confounding as an explanation for any differences found. In an RCT, allocation of the treatment is done randomly to rule out the effects of confounding. RCTs are similar to cohort studies except that we have randomly allocated the ‘exposure’ (treatment) to the individuals in the study.
The design of an RCT is vital in ensuring that the observed results can be attributed to the treatment(s) under consideration. Poorly designed studies are often biased and are therefore uninterpretable.
Study designs
The simplest design is where two groups of patients are assessed. One is given the new treatment and the other is given an existing treatment or a placebo. Allocation of patients to the two groups is done randomly. However, there are many more complex designs. Some examples are given below.
- Type
- Chapter
- Information
- Manual for Research Ethics CommitteesCentre of Medical Law and Ethics, King's College London, pp. 61 - 63Publisher: Cambridge University PressPrint publication year: 2003