USMLE Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
741 Posts
Discussion Starter #1
The formula for odds ratio is easily remembered

The years can either be AD or BC
AD = Anno Domini, After christ
BC = Before Christ

The odds ratio
OD = AD/BC

Of course remember that the A cell is always the disease with the risk and then simply cross to the D cell and divide by the other two cells.

So for example in this 2X2 table
The AD cells are in red and the BC cells are in yellow
The A cell is the number of males with stroke.

2x2.JPG
click image to enlarge

Note in the case of Odds ratio we are measuring the likelihood that a stroke patient is being a male (risk factor) and not the reverse (we are not measuring the probability of getting a stroke if the patient is a male).
 

·
Registered
Joined
·
6 Posts
"Not in the case of Odds ratio we are measuring the likelihood that a stroke patient is being a male (risk factor) and not the reverse".

what do you mean by" not the reverse"??
 

·
Registered
Joined
·
741 Posts
Discussion Starter #5
"Not in the case of Odds ratio we are measuring the likelihood that a stroke patient is being a male (risk factor) and not the reverse".

what do you mean by" not the reverse"??
Odds Ratio: measuring the odds of a risk factor when you already have the disease, i.e. you already have stroke, what's the likelihood that it was caused by male sex. It starts with the disease and ends with risk factor.

While Relative Risk and Attibutable Risk: it starts with the risk factor and ends with the disease, i.e. if you are male then what's the likelihood you'll get stroke.
 
1 - 5 of 5 Posts
Top