这几个地方理解的对吗？谢谢

The likelihood ratio (LR) is the probability of a finding in someone with a disease (judged by a diagnostic standard, e.g. lumbar puncture in meningism) divided by the probability of that finding in someone without disease.An LR greater than 1 increases the probability of disease; an LR of less than 1 reduces that probability. For example, in a person presenting with headache and fever, the clinical finding of nuchal rigidity (neck stiffness) may carry little diagnostic weight, because many patients with meningitis do not have classical signs of meningism (LR of around 1).

LRs do not determine the prior probability of disease, only how a single clinical finding changes it. Clinicians have to take all available information from the history and physical examination into account. If the prior probability is high, a clinical finding with an LR of 1 does not change this.

‘Evidence- based history and examination’ is a term used to describe how clinicians incorporate knowledge about the prevalence and diagnostic weight of clinical findings into the history and physical examination. 

似然比（likelihood ratio，LR）是指患有某病（根据诊断标准判断，如虚性脑膜炎的腰椎穿刺检查）的患者阳性症状的概率与未患病者这一阳性症状概率的比值。LR 大于 1 可增加诊断疾病的概率； LR 小于 1 则可降低该疾病诊断的概率。例如，头痛、发热的患者，颈项强直（颈部僵硬）可能(对诊断脑膜炎)没有诊断权重，因为许多脑膜炎患者并没有典型的虚性脑膜炎体征（LR 约为 1）。

LR 不能确定疾病的先验概率，只能确定单个临床症状在疾病中的占比。临床医生必须考虑到病史和体格检查中的所有可用信息。如果先验概率很高，LR 为1的临床症状是不会改变先验概率的。

“循证病史和体格检查”是一个用来描述临床医生如何将临床症状的发生概率和诊断权重的知识纳入病史和体格检查中的术语。

这几个地方理解的对吗？谢谢