Question

Researchers want to determine the prevalence of Type 2 Diabetes in 30-79 year-old residents of Sugarville, a large metropolitan area. For this purpose, they select a random sample of 4000 people from the area, draw fasting blood, and define Type 2 Diabetes as having fasting blood glucose of 126 mg/dL or higher. The results are shown in the table below.

	Men				Women				Both sexes
Age	Sampled	Have diabetes	Prevalence		Sampled	Have diabetes	Prevalence		Prevalence
30-39	500	25			500	15
40-49	600	54			600	42
50-59	400	72			400	56
60-69	300	90			300	78
70-79	200	62			200	54
All ages

I need help finding the prevalence, please write out the steps for find the prevalence.

Answer 1

Prevalence is the proportion of a population who have a specific characteristic in a given time period.

• For a representative sample, prevalence is the number of people in the sample with the characteristic of interest, divided by the total number of people in the sample.

There are several ways to report prevalence based on timeframe of estimates :

• Point prevalence is the proportion of a population that has the characteristic at a specific point in time.
• Period prevalence is the proportion of a population that has the characteristic at any point during a given time period of interest. “Past 12 months” is a commonly used period.
• Lifetime prevalence is the proportion of a population who, at some point in life has ever had the characteristic.

CALCULATION IS DONE ON EXCEL FOR 5 CASES :

1. for men (for each age # people having diabetes is divided by total # sample in that age) ans : given in prevalence column of men

2. for women (for each age # people having diabetes is divided by total # sample in that age) ans : given in prevalence column of women

3. for all ages in men (total #men having diabetes is divided by total # men sampled) ans: 0.1515

4. for all ages in women (total #women having diabetes is divided by total # women sampled) ans :0.1225

5. for total population (total #people having diabetes is divided by total # people sampled) ans : 0.37

excel output :