YEAR ONE FLASHCARDS
(Q&A)
DATA & STATISTICS:
Correlation & Regression
What is correlation?
Describes the strength and direction of a relationship between two
continuous variables.
What is Correlation measured by?
R number
What range of R numbers is a strong relationship?
±0.8-1
What range of R numbers is a moderate relationship?
±0.6-0.8
What range of R numbers is a weak relationship?
>0.6
What is the difference between positive and negative R numbers?
Indicates a positive or negative relationship between two variables.
What else is needed to prove that the relationship between the
two variables is significant?
P value.
When would you not calculate R for two variables?
If there is a non-linear relationship between two variables.
If the data includes more than one observation on each individual (paired
data).
What is the null hypothesis in terms of R?
R0 = there is no linear relationship between the 2 variables.
R1 = there is a linear relationship between the 2 variables.
, What is a Z value?
Hidden cause of relationship between x and y.
What is the difference between correlation and regression?
Correlation indicates if there is a relationship, regression can be used to
make predictions.
Regression uses R squared value; correlation uses R value.
DRUGS IN HEALTHCARE:
Myocardial Ischaemia as a Drug Target
Why do we need a coronary circulation?
It takes glucose 15.4 hours to diffuse 1cm of ventricle wall.
Cardiomyocytes have high demand for nutrients and oxygen to keep heart
beating.
Why are they called coronary arteries?
They look like a crown.
What happens to the coronary arteries as the heart contracts?
The coronary arteries are compressed each time the heart contracts.
This decreases coronary perfusion and flow.
What is the difference in O2 rate needed by cardiomyocytes
compared to skeletal muscles cells?
Cardiomyocytes require much more oxygen than skeletal muscle.
- 80ml min per 100g compared to skeletal 15.
What are the problems with coronary circulation?
O2 extraction is at a high rate (75%) - cannot extract more if needed.
Systole impairs coronary perfusion - heart rate is crucial.