Homework Sourse5 After first visit patient was included in the risk group w
5) After first visit, patient was included in the risk group, where ptevalence of the disease B is 0.4 To rule in the diagnosis, clinical test with sensitivity 0.70 and specifity 0.79 .What is the probability, that patient has the disease, given he got positive test result? What is the probability, that patient does not have the disease, given he got negative test result?
| Patient, described in the problem 5, has got positive test result. To rule in the diagnosis, doctor ordered | |||||
| to repeated test . Calculate probability, that patient is diseased, given the second test is positive, too. | |||||
| Discuss, whether second test was usefull. Analyse all possible combinations, caclulating | |||||
| probabilities that patient is dseased, given first test is positive, but second - negative, both negative, | |||||
| first negative, second - positive. Summarise data in a table. |
Solution
The probability, that patient has the disease, given he got positive test result=P(the patient having the disease got positive result)/P(He got positive result)=(.7*.4)/0.79=28/79
