Suppose that we want to determine whether or not amount of light exposure is lin
ID: 3059925 • Letter: S
Question
Suppose that we want to determine whether or not amount of light exposure is linked to depression. We identify 5,000 participants across the United States with no intention of moving to a different permanent residence within the next two years and classify them as living in an area with high or low light exposure. We exclude those who are experiencing depression symptoms at baseline. We then follow them up for two years and determine whether they have experienced depression since baseline. There were 1500 participants residing in low-light areas and 3500 participants living in high-light areas. Of those in low-light areas, 500 participants experienced depression, and of those in high-light areas, 500 participants experienced depression. Assume the exposure is low light. Create a 2x2 table. Calculate the attributable risk (per 1000) and interpret this number.
Explanation / Answer
Result:
Suppose that we want to determine whether or not amount of light exposure is linked to depression. We identify 5,000 participants across the United States with no intention of moving to a different permanent residence within the next two years and classify them as living in an area with high or low light exposure. We exclude those who are experiencing depression symptoms at baseline. We then follow them up for two years and determine whether they have experienced depression since baseline. There were 1500 participants residing in low-light areas and 3500 participants living in high-light areas. Of those in low-light areas, 500 participants experienced depression, and of those in high-light areas, 500 participants experienced depression. Assume the exposure is low light. Create a 2x2 table. Calculate the attributable risk (per 1000) and interpret this number.
Low light
High light
Total
Depression
500
500
1000
No Depression
1000
3000
4000
Total
1500
3500
5000
Risk in low light area = 500/1500=0.33333
Risk in highlight area = 500/3500=0.14286
attributable risk = Risk in low light area - Risk in high light area
= 0.33333-0.14286
=0.19047
attributable risk (per 1000) = 190.47
The difference of experienced depression in 1000 exposed and 1000 unexposed individuals is 190.47.
Low light
High light
Total
Depression
500
500
1000
No Depression
1000
3000
4000
Total
1500
3500
5000
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.