Clin Epi and Stats

Question 1

Define construct validity

Answer 1

The ability of a test to measure what it is designed to measure (and not something else)
Ex. test for depression should measure that and not anxiety

Question 2

Define criterion-related validity

Answer 2

The ability of a test to correlate to the gold standard, how accurately it measures what it was designed to

Question 3

What percent did older adults 65+ increase from 2016 to 2021?

Answer 3

19.3% increase

Question 4

What age group was the fastest growing from 2016 to 2021?

Answer 4

Millenials
85+ is one of fastest growing
100+ grew by 16%

Question 5

What is the life expectancy for a man/woman born in 2021?

Answer 5

Man 80 years
Woman 84 years

Question 6

How many people are 85+ yo?

Answer 6

861, 000 (doubled since 2001)

Question 7

What percent of people 85+ live in collective dwelling?

Answer 7

> 25%

Question 8

What is the definition of life expectancy?

Answer 8

The average number of years that members of a population are expected to live

Question 9

What is the definition of life span?

Answer 9

The maximum duration or greatest age reached by individual in a population or species (122 years for humans)

Question 10

How do you calculate relative risk?

Answer 10

RR = % disease exposed / % disease not exposed
= (a/a+b) / (c/c+d)

Question 11

What is the definition of relative risk?

Answer 11

The RATIO of the probability of an event occurring in an exposed group to non-exposed group
RR>1 means exposure increases risk of disease
RR<1 means exposure decreases risk of disease

Question 12

How do you calculate relative risk reduction?

Answer 12

CER-EER / CER
Control event rate
Exposed event rate

Question 13

How do you calculate absolute risk reduction?

Answer 13

CER - EER

Question 14

How do you calculate NNT?

Answer 14

1/ARR
ARR = CER-EER

Question 15

What is the definition of attributable risk?

Answer 15

The portion of disease rate attributable to a certain exposure
For example AR of smoking and lung cancer is 75% which means that 75% of lung cancers are caused by cigarette smoking

Question 16

What are likelihood ratios?

Answer 16

Used to interpret diagnostic tests
The higher the +LR the more likely a patient has disease or condition
LR+ = Sn / 1-Sp
LR- = 1-Sn/Sp

Question 17

What is definition and formula for Sn and Sp?

Answer 17

Sensitivity = SnOUT = High Sensitivity means if it is negative you can rule out
Probability positive test in patient with disease
Sn = TP / TP+FN

Specificity = SpIN = High Specificity means if positive you can rule in
Probability of negative test in person without disease
Sp= TN / TN+FP

Question 18

What is the PPV?

Answer 18

Positive predictive value
TP / TP+FP

Probability that subjectives with positive test actually have the disease

NPV = TN/TN+FN

Question 19

What are some types of bias?

Answer 19

1. Selection bias
2. Recall bias
3. Detection bias

Question 20

What is a cohort study?

Answer 20

Look at those with and without an exposure
Follow them to see if a disease develops

Question 21

What is a case control study?

Answer 21

Look at those who have a disease vs. those without and compare exposures

Question 22

Define a confounder

Answer 22

A variable that is associated or has a relationship with both the exposure and the outcome of interest

Question 23

What is the difference between a cross sectional study and a longitudinal study?

Answer 23

Cross sectional - collect data from a specific point in time
Longitudinal - collect data repeatedly over an extended period of time

Question 24

Define intra-rater reliability vs. inter-rater reliability?

Answer 24

Intra-rater reliability - degree of agreement of same examiner doing test repeatedly
Inter-rater reliability - degree of agreement of different examiners doing the same test

Question 25

Define power

Answer 25

The ability of a test to detect an effect, if the effect actually exists
Detects the probability of rejecting a false null hypothesis

Question 26

What is quality assurance in protocol design?

Answer 26

Program to minimize the possibility of systematic discrepancies in treatment management amongst participating institutions

Question 27

Define generalizability

Answer 27

The degree to which the results of a study are generalizable to the population more broadly (Beyond those included in study)

Question 28

Define validity

Answer 28

The degree to which the results of study are likely to be true, believable and free of bias

Question 29

Define reliability

Answer 29

The reproducibility of a measurement procedure

Question 30

What is the ceiling effect?

Answer 30

Test items aren’t challenging enough for a group
Test score won’t improve even though patient has clinically improved because already reached highest score
MMSE has strong ceiling effect, MOCA not as much

Question 31

What is the floor effect?

Answer 31

When data can’t take on lower value than particular number

Question 32

What is a type I vs. type II error?

Answer 32

Null hypothesis = no difference between treatment and control
Type I error = rejecting null hypothesis when it is true (false positive)
Type II error = failing to reject null hypothesis when it is false (false negative)

Question 33

According to the Canadian Dementia Strategy executive summary what percent of Canadians 65+ were living with diagnosed dementia?

Answer 33

7%

Question 34

According to the Canadian Dementia Strategy executive summary what is the average number of hours spent by family/caregivers to support a person with dementia?

Answer 34

26 hours

Question 35

According to the Canadian Dementia Strategy executive summary what is the projected total health care costs and out of pocket caregiver costs of dementia in 2031?

Answer 35

$8.3 billion total cost
$16.6 billion total health care cost and out of pocket caregiver costs