在随机试验中生成分配序列:机会,而不是选择
Kenneth F Schulz1, David A Grimes
1Family Health International, PO Box 13950, Research Triangle Park, NC 27709, USA. KSchulz@fhi.org
Lancet (London, England)
|February 21, 2002
概括
适当的随机化对于公正的临床试验至关重要. 简单的随机化是防止偏见的最有效方法,研究人员应优先考虑其使用,尽管可能存在群体大小差异.
科学领域:
- 临床研究方法论 临床研究方法论
- 生物统计学 生物统计学
背景情况:
- 随机对照试验 (RCT) 是临床研究中的黄金标准.
- 随机化是RCT的一个关键组成部分,常常被人理解得很差.
- 不当的随机选择引入了选择和混偏见,损害了研究的完整性.
研究的目的:
- 强调在临床试验中适当的随机化非常重要.
- 倡导使用简单的随机化作为偏见预防的首选方法.
- 讨论替代性随机化技术及其对试验设计的影响.
主要方法:
- 讨论简单的 (不受限制的) 随机化作为最基本和最有效的偏见预防方法.
- 检查受限制的随机化程序,如阻断和随机化,以管理样本大小的不平衡.
- 突出了分层随机化在平衡分层内的分配序列中的作用.
主要成果:
- 简单的随机化,虽然基本,在防止偏差方面优于复杂的方法.
- 像阻断随机化这样的受限方法可以帮助减轻样本大小的不平衡.
- 有效的随机化,无论采用何种方法,都需要仔细的规划和执行.
结论:
- 研究人员必须避免非随机分配方法,以防止偏差.
- 应该更频繁地使用简单的随机化,接受潜在的群体规模变化.
- 对随机化方法的明确报告提高了科学准确性和可信度.
相关概念视频
Group Design
The most basic experimental design involves two groups: the experimental group and the control group. The two groups are designed to be the same except for one difference— experimental manipulation. The experimental group gets the experimental manipulation—that is, the treatment or variable being tested—and the control group does not. Since experimental manipulation is the only difference between the experimental and control groups, we can be sure that any differences between the two are due to...
Random Sampling Method
Sampling is a technique to select a portion (or subset) of the larger population and study that portion (the sample) to gain information about the population. Data are the result of sampling from a population. The sampling method ensures that samples are drawn without bias and accurately represent the population. Because measuring the entire population in a study is not practical, researchers use samples to represent the population of interest. Among the various sampling methods used by...
Probability Distributions
The probability of a random variable x is the likelihood of its occurrence. A probability distribution represents the probabilities of a random variable using a formula, graph, or table. There are two types of probability distribution– discrete probability distribution and continuous probability distribution.
A discrete probability distribution is a probability distribution of discrete random variables. It can be categorized into binomial probability distribution and Poisson probability...
A discrete probability distribution is a probability distribution of discrete random variables. It can be categorized into binomial probability distribution and Poisson probability...
Binomial Probability Distribution
A binomial distribution is a probability distribution for a procedure with a fixed number of trials, where each trial can have only two outcomes.
The outcomes of a binomial experiment fit a binomial probability distribution. A statistical experiment can be classified as a binomial experiment if the following conditions are met:
There are a fixed number of trials. Think of trials as repetitions of an experiment. The letter n denotes the number of trials.
There are only two possible outcomes,...
The outcomes of a binomial experiment fit a binomial probability distribution. A statistical experiment can be classified as a binomial experiment if the following conditions are met:
There are a fixed number of trials. Think of trials as repetitions of an experiment. The letter n denotes the number of trials.
There are only two possible outcomes,...
Randomized Experiments
The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias.
Simple randomization
Simple...
Simple randomization
Simple...
Sampling Plans
Sampling is a crucial step in analytical chemistry, allowing researchers to collect representative data from a large population. Common sampling methods include random, judgmental, systematic, stratified, and cluster sampling.
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...


