Lesson 4

a Test with a high sensitivity is good at ruling conditions out. IT is unlikely that a test with high sensitivity will have false positives. Will likely identify most people with the condition properly.

What does SnNout mean?

positive, have

Sensitivity is the number of people who test (positive/negative) for a disease that (have/don't have) the disease.

negative, don't have

Specificity is the number of people who test (positive/negative) for a disease that (have/don't have) the disease.

with

Tests with a high sensitivity identify will properly identify most of the people (with/without) the disorder

without

Tests with a sensitivity will properly identify most of those with/without the disorder.

A test with high specificity rules IN the condition, because it accurately detects people without the condition (healthy people). If someone didn't have the disorder, this test would have most likely correctly identified them as healthy. LOW SPEIFICITY (WHAT WE WANT) MEANS FEW FALSE POSITIVES

What does SpPIN mean?

The percentage of people who tested negative that actually don't have the disease. Formula for this is d/ (c+d)

What is a negative predictive value?

the ratio of people who test positive for the disorder that actually have the condition. formula is a/ a+b

What is a positive predictive value?

The graphial representation between the balance of sensitivity and specificity. The y axis has the sensitivity on it and the x axis has 1-specificity

What is an ROC curve?

It is the percentage of people who test positive for a disease among a group of people who have the disease. Tests with high sensitivity will identify most of the people who have the disorder.

What is sensitivity and what does it tell us?

The percentage of people who test negative for a specific disease that do not have the disease. Tests with high speificity will properly identify most of those who don't have the disease.

What is specificity and what does it tell us?

(true positive + true negative) / sample size. This tells us how good a test is at accurately identifying people who have and don't have the condition

What is the formula for diagnostic accuracy and what does it tell us?

The number of people who actually have the disease at a certain time. (a+c)/N

What is the prevalence for a disoerder?

prevent missing a deadly condition

When would you want to minimize false negatives in a test result?

to not scare people that they have a condition for no reason

When would you want to minimize false positives?

without, negative

negative predictive value is the ability of a test to determine the proportion of patients (with/without) the disease from all the patients with a (positive/negative) test result

with, positive

positive predictive value is the ability of a test to determine the proportion of patients (with/without) the disease from all the patients with a (positive/negative) test result