Randomized Clinical Trial Participant Allocation System
A Randomized Clinical Trial Participant Allocation System is a Clinical Trial Participant Allocation System that randomly assigns a participant to a clinical trial arm.
- AKA: Random Patient-to-Treatment Group Allocation System, Randomized Patient-to-Treatment Group Allocation System, Randomized Clinical Trial Arm Assignment System.
- Context:
- It can be (typically) used to reduce the selection bias in patient allocation procedures.
- It can solve a Randomized Clinical Trial Participant Allocation Task by implementing a clinical trial randomization plan.
- …
- Example(s):
- Counter-Example(s):
- See: Randomization Unit, Online Clinical Trial Randomization Software, Clinical Trial Arm, Blinded Clinical Trial, Placebo-Controlled Clinical Trial, Parallel Clinical Trial, Crossover Clinical Trial, Factorial Clinical Trial, Patient Recruitment System.
References
2022a
- (ClinicalTrials.gov, 2022) ⇒ https://clinicaltrials.gov/ct2/about-studies/glossary Retrieved:2022-01-20.
- QUOTE: Randomized allocation: A type of allocation strategy in which participants are assigned to the arms of a clinical trial by chance.
2022b
- (Spirit, 2022) ⇒ https://www.spirit-statement.org/methods-assignment-of-interventions-for-controlled-trials-16-17/ Retrieved:2022-01-20.
- QUOTE: Method of generating the allocation sequence (e.g., computer-generated random numbers), and list of any factors for stratification. To reduce predictability of a random sequence, details of any planned restriction (e.g., blocking) should be provided in a separate document that is unavailable to those who enrol participants or assign interventions.
- Example
"Participants will be randomly assigned to either control or experimental group with a 1:1 allocation as per a computer generated randomisation schedule stratified by site and the baseline score of the Action Arm Research Test (ARAT; <= 21 versus >21) using permuted blocks of random sizes. The block sizes will not be disclosed, to ensure concealment.
- Explanation
Participants in a randomised trial should be assigned to study groups using a random (chance) process characterised by unpredictability of assignments. Randomisation decreases selection bias in allocation; helps to facilitate blinding/masking after allocation; and enables the use of probability theory to test whether any difference in outcome between intervention groups reflects chance.
Use of terms such as “randomisation” without further elaboration is not sufficient to describe the allocation process, as these terms have been used inappropriately to describe non-random, deterministic allocation methods such as alternation or allocation by date of birth. In general, these non-random allocation methods introduce selection bias and biased estimates of an intervention’s effect size, mainly due to the lack of allocation concealment (...). If non-random allocation is planned, then the specific method and rationale should be stated.
- Explanation
- Example
- QUOTE: Method of generating the allocation sequence (e.g., computer-generated random numbers), and list of any factors for stratification. To reduce predictability of a random sequence, details of any planned restriction (e.g., blocking) should be provided in a separate document that is unavailable to those who enrol participants or assign interventions.
2022c
- (PSU, 2022) ⇒ PennState Eberly College Of Science (2022). "Lesson 8: Treatment Allocation and Randomization". In: STAT 509 - Design and Analysis of Clinical Trials, Retrieved:2022-01-20.
- QUOTE: Treatment allocation in a clinical trial can be randomized or nonrandomized. Nonrandomized schemes, such as investigator-selected treatment assignments, are susceptible to large biases. Even nonrandomized schemes that are systematic, such as alternating treatments, are susceptible to discovery and could lead to bias. Obviously, to reduce biases, we prefer randomized schemes. Credibility requires that the allocation process be non-discoverable. The investigator should not know what the treatment will be assigned until the patient has been determined as eligible. Even using envelopes with the treatment assignment sealed inside is prone to discovery.
Randomized schemes for treatment allocation are preferable in most circumstances. When choosing an allocation scheme for a clinical trial, there are three technical considerations:
- QUOTE: Treatment allocation in a clinical trial can be randomized or nonrandomized. Nonrandomized schemes, such as investigator-selected treatment assignments, are susceptible to large biases. Even nonrandomized schemes that are systematic, such as alternating treatments, are susceptible to discovery and could lead to bias. Obviously, to reduce biases, we prefer randomized schemes. Credibility requires that the allocation process be non-discoverable. The investigator should not know what the treatment will be assigned until the patient has been determined as eligible. Even using envelopes with the treatment assignment sealed inside is prone to discovery.
- Randomization procedures provide the best opportunity for achieving these objectives.
2014
- (Kim & Shin, 2014) ⇒ Jeehyoung Kim, and Wonshik Shin (2014)."How to Do Random Allocation (Randomization)".In: Clinic in Orthopedic Surgery (CiOS), 6(1):103-109. DOI:10.4055/cios.2014.6.1.103.
- QUOTE: Randomized controlled trials (RCT) are known as the best method to prove causality in spite of various limitations. Random allocation is a technique that chooses individuals for treatment groups and control groups entirely by chance with no regard to the will of researchers or patients' condition and preference. This allows researchers to control all known and unknown factors that may affect results in treatment groups and control groups (...)
How to implement these techniques can vary by each trial. The following is only one of the examples of how these can be implemented in real trial. You may change the details of the example for your experiment. Figures of randomization and allocation concealment can also be adjusted to your needs (Fig. 5).
- QUOTE: Randomized controlled trials (RCT) are known as the best method to prove causality in spite of various limitations. Random allocation is a technique that chooses individuals for treatment groups and control groups entirely by chance with no regard to the will of researchers or patients' condition and preference. This allows researchers to control all known and unknown factors that may affect results in treatment groups and control groups (...)
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2011
- (Suresh, 2011) ⇒ K. P. Suresh (2011). "An Overview of Randomization Techniques: An Unbiased Assessment of Outcome in Clinical Research". In: Journal of Human Reproductive Sciences, 4(1):8-11. DOI:10.4103/0974-1208.82352.
- QUOTE: A good experiment or trial minimizes the variability of the evaluation and provides unbiased evaluation of the intervention by avoiding confounding from other factors, which are known and unknown. Randomization ensures that each patient has an equal chance of receiving any of the treatments under study, generate comparable intervention groups, which are alike in all the important aspects except for the intervention each groups receives. It also provides a basis for the statistical methods used in analyzing the data. The basic benefits of randomization are as follows: it eliminates the selection bias, balances the groups with respect to many known and unknown confounding or prognostic variables, and forms the basis for statistical tests, a basis for an assumption of free statistical test of the equality of treatments. In general, a randomized experiment is an essential tool for testing the efficacy of the treatment (...)
Many procedures have been proposed for the random assignment of participants to treatment groups in clinical trials. In this article, common randomization techniques, including simple randomization, block randomization, stratified randomization, and covariate adaptive randomization (...)
- QUOTE: A good experiment or trial minimizes the variability of the evaluation and provides unbiased evaluation of the intervention by avoiding confounding from other factors, which are known and unknown. Randomization ensures that each patient has an equal chance of receiving any of the treatments under study, generate comparable intervention groups, which are alike in all the important aspects except for the intervention each groups receives. It also provides a basis for the statistical methods used in analyzing the data. The basic benefits of randomization are as follows: it eliminates the selection bias, balances the groups with respect to many known and unknown confounding or prognostic variables, and forms the basis for statistical tests, a basis for an assumption of free statistical test of the equality of treatments. In general, a randomized experiment is an essential tool for testing the efficacy of the treatment (...)
1999
- (Altman & Bland, 1999) ⇒ Douglas G. Altman, and J. Martin Bland (1999). "Treatment Allocation in Controlled Trials: Why Randomise?". In: BMJ, 318(7192):1209. DOI:10.1136/bmj.318.7192.1209.
- QUOTE: The main reason for using randomisation to allocate treatments to patients in a controlled trial is to prevent biases of the types described above. We want to compare the outcomes of treatments given to groups of patients which do not differ in any systematic way. Another reason for randomising is that statistical theory is based on the idea of random sampling. In a study with random allocation the differences between treatment groups behave like the differences between random samples from a single population. We know how random samples are expected to behave and so can compare the observations with what we would expect if the treatments were equally effective