3.4.1 Epidemiology of Diabetes Flashcards
How many people in the world are estimated to have diabetes?
9% of all adults >18yo
When is screening recommended for diabetes?
Screening is routinely recommended for men and women with a BMI of 25 or higher.
What point on this graph is perfectly sensitivity?
B
High sensitivity and a negative result will do what?
SNOUT
High sensitivity will and a negative result will rule out disease
What is a negative likelihood ratio? (1, <1,<.1)
LR-:
1: test has no discriminatory value
< 1 - Persons without disease more likely to yield a negative test than a person with disease
<.1 - Test has high diagnostic value
What is sensitivity?
The ability of a test to correctly identify who has a disease
Is the oral glucose tolerance test good?
Most sensitive test
Likelihood ratio is 9.46
What is pretest probability?
Probability of a disease before a test is done
What are the risk factors associated with Type 1 diabetes?
Autoimmune, genetic and environmental
What is prediabetes?
What point on this graph is perfect specificity?
E
How is the age adjusted prevalance of diabetes among adults in 2014?
What is the prevalance of diabetes among the US population?
- 3%
- 1m people
28% undiagnosed
How would test performance change if the cutoff for a test was 140 instead of 126?
The test would have a lower sensitivity and increase the specificity
Compare the Sensitivity, Convenience, Cost, and Associated risks of the glucose tolerance test, A1c, and FPG.
When choosing a cutoff point for a test what are the import considerations?
How does percentage of people with diabetes change with age?
Increases with age
20-44 : 4.1%
45 - 64 : 16.2%
>64 : 21.8%
What is the specificity of a test?
The ability of a test to identify those who do not have disease.
How is obesity distributed through the United States?
What is SPIN?
What is diabetes mellitus?
Disease where blood glucose levels are elevated
Cause - Insufficient insulin or insulin resistance
How can you use a pretest probability and likelihood ratio to get a posttest probability?
Using a normogram.
Take the pretest probability and use the likelihood ratio to find the post test.
How does a prior history of gestational diabetes affect a patients risk of having diabetes?
Risk of acquiring diabetes is 35-60%
ANSWER THIS!!!!
6.5%
Due to the early treatment of diabetes is not invasive
How does type 2 diabetes prevalances change in kids less than 10 years old and between 10-19 yo?
What is a positive likelihood ratio?
LR+:
1 - test has no discriminatory value
>1 - Persons with disease more likely than persons without disease to have positive test
>10 - Test has high diagnostic value
What is important about high specificity tests?
High specificity few false positives
False negatives
What are the symptoms associated with diabetes?
Draw out a 2x2 table and write the equation for specificity and sensitivity
How is the prevalance of diabetes distributes among different races?
What is the best study design to compare two treatments?
Randomized control trial
Discuss the process of choosing a cutoff point for fasting plasma glucose.
If you choose a cutoff point that is low, like 110, you get a more sensitive test (the test does a good job correctly identifying those with disease). Remember, a highly sensitive is useful in ruling out disease (SNNOUT): if a negative test result comes back from a highly sensitive test, we can have some confidence that it is a true negative result. If you choose a cutoff that is low, like 170, you get a more specific test (the test does a good job correctly identifying those without disease). A highly specific test is useful in ruling in disease (SPPIN).
What is important to note about high sensitivity tests?
Few false negatives
Higher false positives
In a 2x2 table how would you determine the risk ratio?
What is the validity of a test?
Ability to distinguish between who has and who doesnt
Which med student was an honorary cheerleader for a day?
Brannon Donovan
What are some risk factors associated with T2 diabetes? (7)
Obesity
Physical inactivity
Impaired glucose tolerance
Prior history of gestational diabetes
Older age
FH of diabetes
Race and ethnicity
What is a likelihood ratio?
