Last time, we give a SAS example of Risk Difference to test if two groups are experiencing the same proportion of a certain event. In order to understand the topic better, we will go over Risk Ratio. Definition: Risk Ratio or Relative Risk (RR) is the probability that an event occurs i...
其实在临床科研中,也有“真假美猴王”的存在,那就是相对危险度(Relative Risk),一种我们在队列研究或者临床试验研究中常用于反应暴露(包括某种特征、某种行为或接触某种研究物质)与结局关联强度的指标。细心的同学可能会发现,相对危险度也叫危险比(Risk Ratio)或率比(Rate Ratio),虽然它们的缩写都是RR,但是所代表的...
It is very easy to mix the concept forOdds Ratioand Risk Ratio. Odds Ratio represents the odds of an event in group 1 compared to the event of odds in group 2, where odds means the event over non-event. Risk Ratio means the probability of an event occurring in group 1 compared to t...
it can be used to describe the risk of developing a disease for people who are exposed to a particular factor relative to people who are not exposed to the same factor. The relative risk is defined as the ratio of probabilities of developing a certain...
However, in a case control study, we use odds ratio instead of risk ratio due to the fact ...
还能利用优势比估算相对危险，实现高效研究。综上所述，优势比与相对危险在医学统计学中扮演着互补角色。在特定情况下，优势比能够近似估算相对危险，使研究者能够更有效地评估罕见病与因素之间的关联性，实现研究目标的同时减少资源消耗。这种巧妙的数学关联，正是医学研究中智慧与效率的体现。
我们发现抗生素治疗并不能预防患者的细菌感染(Risk Ratio=1),但是可以延缓患者的细菌感染(Rate Ratio=0.625)。换句话说,在一定时间段内,抗生素治疗可能可以降低患者发展为细菌感染的风险。总之,我们需要确定研究目的后再选择Risk ratio或Rate Ratio。另外,在以后文献阅读和二次数...
Relative Risk (RR) Relative risk (RR) is a ratio of the absolute risks for two groups. It tells us how the chances in one group relates to those in another. This statistic helps you understand how a particularfactor, like a treatment or lifestyle change, affects the outcome probability. ...
病例对照是回顾性研究,我们拿到的样本已经分类为得病的和没得病的,所以无法在此基础上计算相对危险了。可是,我们仍旧希望通过回顾分析因素和疾病之间的关系,于是就使用优势比来估算相对危险。 来看看下面这张图,红色的面积表示有危险因素的人数,灰色面积表示没危险因素的人数。优势比 = 得病组的红灰面积比/没得病组的...
而病例对照研究，作为历史的见证者，虽然无法直接计算相对危险，但它却巧妙地通过优势比来揭示关系。优势比，即得病组中带有危险因素的人数与无危险因素的人数之比，如果这个比值大于1，危险因素与疾病之间的关联便浮出水面。数学的桥梁 优势比的计算公式OR = ad / bc，看似简单，但它与相对危险的近似...