Anemia is a common health problem with potentially serious consequences. Currently, blood is drawn to screen for anemia, but a non-invasive, quicker, and cheaper test would be preferred by patients as well as by the health care system. The gold-standard blood test is being compared to a new portable scanner that detects hemoglobin levels under the thin skin on the underside of the wrist.

A pilot study recruited 1000 patients in a primary care setting to be assessed for anemia. There were 119 patients who tested positive for anemia based on the blood test; 101 of these 119 were also identified with anemia based on the wrist scanner. In contrast, the wrist scanner identified 116 patients with anemia.

Show all steps in your calculations when applicable, including formulae,and provide a summary sentence that states your results in full.

3. Fill 9 cells of the data table below, using the information provided above. [1 mark]

		Blood Test
		Anemia Present	Anemia Absent	Total
Wrist Scanner	Anemia Present
Anemia Absent
	Total

4. Sensitivity and specificity:

a. Calculate sensitivity and specificity. [4 marks]

b. What does the sensitivity and specificity results mean? [3 marks] Be sure to include definitions of these concepts applied to the screening scenario provided and cite the results that you have calculated.

200 word count

5. Positive and negative predictive value:

a. Calculate positive predictive value and negative predictive value. [4 marks]

b. What do the positive and negative predictive value results mean? [3 marks] Be sure to include definitions of these concepts applied to the screening scenario provided and cite the results that you have calculated.

200 word count

6. Would sensitivity or specificity be a higher priority for this screening program? Explain your reasoning, discussing both sensitivity and specificity. [6 marks]

200 word count