Due to the increasing numbers of HIV positive cases in the past decade, a private health company developed a new brand of a colorimetric test kit. This kit is based on the antibody-antigen test. During product development, the company's research and development team conducted a study to determine how the test kit compares with the Western Blot Assay. In partnership with the national health department, a total of 1,000 subjects were included. There were 574 subjects who had positive results in the colorimetric test kit of which 141 were western blot assay negative. The western blot assay was positive in 519 subjects.

Question

Due to the increasing numbers of HIV positive cases in the past decade, a private health company developed a new brand of a colorimetric test kit. This kit is based on the antibody-antigen test. During product development, the company's research and development team conducted a study to determine how the test kit compares with the Western Blot Assay. In partnership with the national health department, a total of 1,000 subjects were included. There were 574 subjects who had positive results in the colorimetric test kit of which 141 were western blot assay negative. The western blot assay was positive in 519 subjects.

Show the contingency (2x2) table and what is the percentage of true positive ( 5 points)

Answer 1

To create the contingency table, we need to list the number of subjects in each category. Based on the given information, we can construct the table as follows:

| Colorimetric Test Kit Positive | Colorimetric Test Kit Negative |
-------------------|-------------------------------|-------------------------------|
Western Blot Assay Positive | 433 | |
Western Blot Assay Negative | 141 | |

Now, let's calculate the missing values. Since the total number of subjects is given as 1,000, we can fill in the remaining cells:

| Colorimetric Test Kit Positive | Colorimetric Test Kit Negative |
-------------------|-------------------------------|-------------------------------|
Western Blot Assay Positive | 433 | 519 |
Western Blot Assay Negative | 141 | 417 |

Now, we can calculate the percentage of true positive cases. True positive refers to cases where the colorimetric test kit is positive, and the Western Blot Assay is also positive. In this case, the cell value is 433.

Divide the true positive cases (433) by the total number of subjects (1,000) and multiply by 100 to get the percentage:

(433 / 1,000) * 100 = 43.3%

Therefore, the percentage of true positive cases is 43.3%.

yes

To create the contingency table, we need to list the number of subjects in each category. Based on the given information, we can construct the table as follows: