sklearn实战-乳腺癌细胞数据挖掘(博主亲自录制视频教程)

https://study.163.com/course/introduction.htm?courseId=1005269003&utm_campaign=commission&utm_source=cp-400000000398149&utm_medium=share

医药统计项目联系:QQ :231469242

https://wenku.baidu.com/view/8d506a9cda38376baf1fae84.html

sensitivity 敏感性:患病且检测阳性概率

specificity特异性:健康且检测阴性概率

ppv(positive predict value)阳性预测值:指机器检查后,患病概率多高,这和疾病流行程度有关

npv(negative predict value)阴性预测值:指机器检查后,非患病概率多高,这和疾病流行程度有关

但现实中机器会把很多正常人也检查出阳性,所以没病的人也可能检查出阳性

所以阳性预测值和阴性预测值可以很好预测你检查结果后,患病概率

阳性还和疾病流行程度有关,疾病是罕见病,即使机器检测阳性,概率也不会很高

阳性预测率:当你被检查出阳性时,你想知道你真的患病概率。

阳性预测率=患病且检查出阳性数量/(患病且被诊断阳性数量+不患病且被诊断阳性数量)

阴性预测率:检查阴性时,健康概率

阴性预测率=不患病且检查出阴性数量/(患病且被诊断阴性数量+不患病且被诊断阴性数量)

案例中,总人口1000人(A+B+C+D),90%患病率,机器敏感度低50%,但阳性预测值高90%

如果疾病流行度很低,10%感染率,虽然敏感度50%,但阳性预测率只有10%

阴性时,用于排除疾病

用于前期筛选工具

敏感度和疾病流行程度无关

For example, pregnancy tests have a high sensitivity: when a woman is pregnant,
the probability that the test is positive is very high.
In contrast, an indicator for an attack with atomic weapons on the White House
should have a very high specificity: if there is no attack, the probability that the
indicator is positive should be very, very small.
While sensitivity and specificity characterize a test and are independent of
prevalence, they do not indicate what portion of patients with abnormal test results
are truly abnormal. This information is provided by the positive/negative predictive
value (PPV/NPV). These are the values relevant for a doctor diagnosing a patient:
when a patient has a positive test result, how likely is it that the patient is in fact sick?
Unfortunately, as Fig. 7.8 indicates, these values are affected by the prevalence of the
disease. The prevalence of a disease indicates how many out of 100,000 people are
affected by it; in contrast, the incidence gives the number of newly diagnosed cases
per 100,000 people. In summary, we need to know the prevalence of the disease as
well as the PPV/NPV of a test to provide a sensible interpretation of medical test
results.
Take for example a test where a positive test results implies a 50% chance
of having a certain medical condition. If half the population has this condition,
a positive test result tells the doctor nothing. But if the condition is very rare, a
positive test result indicates that the patient has a fifty–fifty chance of having this
rare condition—a piece of information that is very valuable.
Figure 7.8 shows how the prevalence of a disease affects the interpretation
of diagnostic results, with a test with a given specificity and sensitivity: a high
prevalence of the disease increases the PPV of the test, but decreases the NPV;
and a low prevalence does exactly the opposite. Figure 7.9 gives a worked example.

疾病流行率与阳性预测值关系密切

即使敏感度很高,但ppv也可能低,因为机器预测阳性错误的数量太多。所以敏感度也不是唯一判断金指标

阳/阴性预测值Positive/negative Predictive Value(推荐AA)的更多相关文章

  1. light oj 1294 - Positive Negative Sign

    1294 - Positive Negative Sign   PDF (English) Statistics Forum Time Limit: 2 second(s) Memory Limit: ...

  2. 1294 - Positive Negative Sign(规律)

    1294 - Positive Negative Sign   PDF (English) Statistics Forum Time Limit: 2 second(s) Memory Limit: ...

  3. 智课雅思短语---二、exert positive/ negative effects on…

    智课雅思短语---二.exert positive/ negative effects on… 一.总结 一句话总结:对…产生有利/不利的影响 1.the advantages far outweig ...

  4. 零宽断言 -- Lookahead/Lookahead Positive/Negative

    http://www.vaikan.com/regular-expression-to-match-string-not-containing-a-word/ 经常我们会遇到想找出不包含某个字符串的文 ...

  5. LightOJ - 1294 - Positive Negative Sign(规律)

    链接: https://vjudge.net/problem/LightOJ-1294 题意: Given two integers: n and m and n is divisible by 2m ...

  6. Amazon评论数据的预处理代码(Positive & Negative)

    Amazon评论数据的预处理代码,用于情感分析,代码改自 https://github.com/PaddlePaddle/Paddle/tree/develop/demo/quick_start/da ...

  7. Python/spss-多元回归建模-共线性诊断2(推荐AA)

    sklearn实战-乳腺癌细胞数据挖掘(博客主亲自录制视频教程) https://study.163.com/course/introduction.htm?courseId=1005269003&a ...

  8. ROC 曲线/准确率、覆盖率(召回)、命中率、Specificity(负例的覆盖率)

      欢迎关注博主主页,学习python视频资源 sklearn实战-乳腺癌细胞数据挖掘(博主亲自录制视频教程) https://study.163.com/course/introduction.ht ...

  9. 深层解析:构建facebook应用商店推荐引擎

    Under the Hood: Building the App Center recommendation engine   As more apps on Facebook Platform ha ...

随机推荐

  1. 字符串拆分和拼接(含list拼接)---基于python

    最近得一超长字符串如下: l=“5245474953544552207369703a3137322e3136312e31302e323232205349502f322e300d0a5669613a20 ...

  2. scrum立会报告+燃尽图(第二周第六次)

    此作业要求参见:https://edu.cnblogs.com/campus/nenu/2018fall/homework/2251 一.小组介绍 组名:杨老师粉丝群 组长:乔静玉 组员:吴奕瑶.公冶 ...

  3. 对懂球帝ios版的用户体验

    用户界面: 主页面是资讯页面 这个设计很棒 对球迷来说 每天最关注的就是 我的主队赢了输了 其次界面以绿色为主 很有绿茵场的感觉 很符合足球狗的口味 记住用户的选择: 这个应用 有一个 球队的关注 选 ...

  4. bat获取当前日期的前一天

    批处理做这样的事情很麻烦,你可以用cscript来实现,比如把下面的内容保存为a.js文件:var d=new Date();d.setTime(d.getTime()-24*3600*1000);v ...

  5. lintcode-65-两个排序数组的中位数

    65-两个排序数组的中位数 两个排序的数组A和B分别含有m和n个数,找到两个排序数组的中位数,要求时间复杂度应为O(log (m+n)). 样例 给出数组A = [1,2,3,4,5,6] B = [ ...

  6. shader language学习(1)——shader language简介背景

    shader language,称为着色语言,shade在英语是阴影.颜色深浅的意思.shader language基于物体本身属性和光照条件,计算美格橡塑的颜色值. 实际上这种解释具有明显的时代局限 ...

  7. The goal you specified requires a project to execute but there is no POM in this directory

    [INFO] Scanning for projects... [INFO] ------------------------------------------------------------- ...

  8. python配置文件读取

    在代码实现的过程中,我们经常选择将一些固定的参数值写入到一个单独的配置文件中.在python中读取配置文件官方提供了configParser方法. 主要有如下方法(找官文):   (这家伙很懒,直接复 ...

  9. [翻译]API Guides - Layouts

    官方文档地址:http://developer.android.com/guide/topics/ui/declaring-layout.html PS:API Guides里面的内容不免都简单些,翻 ...

  10. css & text-overflow & ellipsis

    css & text-overflow & ellipsis https://developer.mozilla.org/en-US/docs/Web/CSS/text-overflo ...