4. A research group wanted to know if daily consumption of energy drinks was a r

ID: 199714 • Letter: 4

Question

4. A research group wanted to know if daily consumption of energy drinks was a risk factor for hypertension in college-aged adults. The enrolled two groups of students as either 'drinkers' or 'non-drinkers' and measured their blood pressure monthly to determine if hypertension developed within one year. The results are as follows: Drinkers Non-drinkers Developed hypertension 65 106 Did not develop hypertension 435 1394 a. Is this a cohort or case control design and how do you know? (1 point) b. Calculate either relative risk or an odds ratio to test the link between exposure and disease. Which metric is more appropriate and why? (3 points) c. How much risk of hypertension (if any) can you attribute to consumption of energy drinks? (3 points)

Explanation / Answer

Ans a: This is a cohort as in this case the people are exposed to a risk factor; the energy drinks and their chance of developing hypertension are compared.

Ans b:

Developed hypertension

Did not develop hypertension

Drinkers

65 (a)

435 (b)

Non drinkers

106 (c)

1396 (d)

Relative risk ratio= (a/a+b)/( c/c+d)

RR= (65/65+435)/ (106/106+1396)

= 0.13/0.071

= 1.84

Odds Ratio= (a/c)/b/d)

= (65/106)/ (435/1396)

= 0.61/0.31

= 1.96

A relative risk is much easier to interpret and makes much more sense. A relative risk of 2.0 means that the affected group has two times the risk of a non-affected group.

Ans c: As both the odds ratio and the relative ratio are more than one, this means that there is twice the risk of developing hypertension for the drinkers.