Critical numbers

Question 1

What is the odds ratio?

Answer 1

ratio of the probability of an event occurring to the probability of it not occurring

Question 2

How do we interpret the odds ratio?

Answer 2

OR = 1 there is no difference between the groups
OR <1 the odds of the outcome occurring are lower in the numerator (group of interest)
OR >1 the odds of the outcome are greater

Question 3

How many variables can logistic regression have?

Answer 3

One predictor (like linear regression) or multivariable

Question 4

What is the difference between linear and logistic regression?

Answer 4

Linear = enables the prediction of outcome values on a numeric scale

logistic = enables the prediction of the probability of an outcome occurring based on multiple characteristics/risk factors

Question 5

When is logistic regression useful?

Answer 5

in medical research
- shows associations between exposures and categorical outcomes
- clinical risk prediction

Question 6

What are some preventative factors for drug abuse?

Answer 6

Self-control
Parental monitoring and support
Positive relationships
Neighourbood resources
Academic achievement
School anti-drug policies

Question 7

What are some risk factors for drug abuse?

Answer 7

Aggressive childhood behaviour
Lack of parental support
Community deprivation/poverty
Drug experimentation
Poor social skills
Availability of drugs at schools