Question

. Interpret the odds ratio to determine the strength of association between the potential sources of exposure and the disease. Tip: Use the data in Table 2 of the final project research study to calculate the odds ratio. Show your work.

Table 2. Potential sources of exposure to Salmonella, Trinidad and Tobago

Case-Control Study, March 1998 – May 1999.

Exposure*	Matched Odds	Ratio p-value
Ate Chicken	0.5	0.4
Ate shell eggs	8.8	<0.001
Ate dishes that contained raw or undercooked eggs Ate ground beef	18.9	0.001
Ingested powdered milk	1.5	0.2
Exposed to live chickens	1.3	0.4
Bought refrigerated eggs	0.1	<0.001
Refrigerated eggs at home	0.03	<0.001
Ate ground beef	1.3	0.6

*in the 3 days before onset of illness in the associated case

Answer 1

Answer:

An odds ratio is a relative measure of effect, which allows the comparison of the intervention group of a study relative to the comparison or placebo group.  

also ,

If the OR is > 1 the control is better than the intervention.

If the OR is < 1 the intervention is better than the control.

Now from the table lets first check the p values that are significant. Assuming an alpha of 0.05 , any p value that is less than 0.05 are considered signficant , highlighted in red

for ate shell eggs the value is 8.8
this means that the odds are 8.8 times higher for the exposure group as compatred to the control group

likewise ,
ate dishes has a value of 18.9 , this means that the exposure has 18.9 times higher odds of exposure to salmonella than the control group

bought regrigerated eggs and refiregerated eggs at home has odds ratio of 0.1 and 0.03 respectively , which are quite close to zero
hence the referigerated eggs either bought or at home are having equal odds for exposure and the control group