epigenetics

Question 0

what is X bar

Answer 0

sample mean

Question 1

what is mu?

Answer 1

real mean.

Question 2

How are variance and standard deviation related?

Answer 2

SD = sqrt(variance)

Question 3

What is variance in data?

Answer 3

How far the data points are spread out. (variance is never a negative number)

Question 4

What is conitinuous data?

Answer 4

Data that is measured.

Question 5

What is Categorical Data?

Answer 5

Data that has values assigned.

Question 6

What is proportion?

Answer 6

Any part-to-whole ratio.

Question 7

What is Rate?

Answer 7

Proportion expressed as cases per 100K people. Rate is an estimate of risk.

Question 8

What is incidence?

Answer 8

New cases over period of time in defined population, ie- new ebola cases in West Africa over last 30 days. Not an estimate of risk.

Question 9

What is prevalence?

Answer 9

Snapshot of total cases in a defined population, -ie 2.9 million American woman with breast cancer.

Question 10

What is Relative Risk?

Answer 10

• Risk of cancer among smokers: 17/100
• Risk of cancer among non-smokers: 1/100
• Relative Risk (RR) = 17/1

Question 11

What is an Odds Ratio?

Answer 11

• Risk of cancer among smokers: 17/100
• Odds of cancer among smokers: 17/83 = 0.2
• Risk of cancer among non-smokers: 1/100
• Odds of cancer among non-smokers: 1/99 ~ .01
• Odds ratio: 0.2/0.01 = 20

Question 12

What Relative Risk means no difference between groups? What Odds Ratio means no difference between groups?

Answer 12

1

Question 13

What is the Number Needed to Harm (NNH)?

Answer 13

Smoking increases mortality by 16%.

1 / 0.16 = 6.25. For every 6.25 smokers, 1 will die.

Question 14

What is Number Needed to Treat?

Answer 14

Use Attributable Risk.

If AR = 0.03, then 1 / 0.03 = 32 need to be treated in order to save a life.

Question 15

What is Attributable Risk?

Answer 15

AR = Risk of Exposed - Risk of Unexposed

17% of smokers - 1% of non-smokers = 16% difference