Question

Cohort study – Calculating attributable risk for exposure to formula feeding among individuals who develop Type II diabetes by age 16

	DISEASE TYPE II BY AGE 16	NO DISEASE/NO TYPE II DIABETES BY AGE 16
EXPOSED formula fed	321	112
NOT EXPOSED BREASTFEEDING	177	408

Calculate the attributable risk (AR) among the exposed:

Interpret the AR you calculated:

Answer 1

Solution :

A Cohort Study is given. We have to calculate the Attributable Risk for exposure to formula feeding among individuals who develop Type II Diabetes by Age 16. The Cohort Study Table is given below !!

Cohort Study Table

	DISEASE TYPE II BY AGE 16	NO DISEASE/NO TYPE II DIABETES BY AGE 16	Total
EXPOSED formula fed	321	112	433
NOT EXPOSED BREASTFEEDING	177	408	585
Total	498	520	1018

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(a) To calculate the Attributable Risk (AR) among the exposed :

We know that the Attributable Risk (AR) is nothing but an estimate of the Excess Risk or the difference of the risks between the Exposed (to a factor or a disease) and Non - Exposed group in a specific population...

  

  

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(b) To interpret the Attributable Risk (AR) among the exposed :

Interpretation : We got the Attributable Risk (AR) = 0.5413395 which implies that the excess risk or the risk difference between the exposed and the non-exposed groups in the specific population is about 0.5413395. Or in other words, we can say that there were an excess of approximately 54 persons with Type II Diabetes disease per 100 persons who were exposed (formula fed) compared to the group that was not exposed (breast - feeding).

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