Odd Ration and Relative Risk
Studies of the link between prone sleeping position (lying face down) and increased risk of sudden infant death syndrome have been criticized on grounds of recall bias and not taking into account possible confounding effects. To avoid recall bias and to allow measurement of important biologic factors a prospective cohort study on prone sleeping position and sudden infant death syndrome (SIDS) was conducted.
Results of the study are shown below in Table 1.
Table 1: Results from a cohort study (n=2,607) of prone sleeping position and sudden infant death syndrome (SIDS)
SIDS No SIDS Total
Prone position 9 837 846
Non-prone position 6 1755 1761
Total 15 2592 2607
Question 1
1 / 1 pts
What is the absolute risk per 1,000 of SIDS in the study population?
5.75
Question 2
1 / 1 pts
Calculate the measure of association for this cohort study.
3.1
Question 3
1 / 1 pts
Interpret the measure you calculated in Q2:
Your Answer:
babies in prone sleeping position are 3.1 times more likely to develop SIDS than babies in the non-prone position.
Question 4
1 / 1 pts
Calculate the percent attributable risk of SIDS in the exposed population.
The answer is:
67.9
Question 5
1 / 1 pts
Interpret the percent attributable risk of SIDS in the exposed population.
Your Answer:
67.9 % of incidence of SIDS among those in the prone position is attributable to their prone position.
