Question

No plagiarism please

Verga Enterprises is conducting a study to assess the relationship between smoking and colorectal cancer (CRC). In the survey that was conducted, 20 out of 100 non-smokers had CRC, while 40 out of 60 smokers had CRC.

(a) What makes this a Cross Sectional study design?

(b) Complete the 2x2 table.

(c) What are the odds of CRC among smokers?

(d) What are the odds of disease among non-smokers.

(e) Calculate the prevalence ratio.

(f) Interpret the prevalence ratio.

(g) What is the value of the prevalence odds ratio (POR)?

(h) What can be concluded about the relationship between the exposure and health outcome?

Answer 1

a). This particular case is an cross sectional study because of the following reasons:

1. The above study took place at a single point off time
2. Manipulating variables are not present in this case. Only variables present are smokers, non smokers and CRC, non CRC
3. This case allows us to see at numerous characteristics at once in a given population.

b).

c). 40/20 = 2:1 -> odds of CRC among smokers

d). 20/80 = 1:4 -> odds of CRC among non-smokers

e). (40÷(40+20))/(20÷(20+80)) = 10/3

f). The ratio of the proportion of the persons with CRC over the proportion of smokers

g). 8

h). Smokers are more prevalent to the CRC while non smokers are very less prevalent to CRC