can someone please help with this. Any ideas?
USMLE Step 1 Community
189 followers
25 Jun 2024
calculating PPV from specificty and sensitivity
Question:
A large epidemiological study investigating the prevalence of an autoimmune disease is being conducted. Based on prior studies, the researchers know the disease prevalence in the population is approximately 0.5%. They are using a diagnostic test with a sensitivity of 95% and specificity of 98%. What is the positive predictive value of the test in this population?
Options:
A)Approximately 50%
B)Approximately 20%
C)Approximately 2%
D)Approximately 1%
E)Less than 1%
calculating PPV from specificty and sensitivity
Question:
A large epidemiological study investigating the prevalence of an autoimmune disease is being conducted. Based on prior studies, the researchers know the disease prevalence in the population is approximately 0.5%. They are using a diagnostic test with a sensitivity of 95% and specificity of 98%. What is the positive predictive value of the test in this population?
Options:
A)Approximately 50%
B)Approximately 20%
C)Approximately 2%
D)Approximately 1%
E)Less than 1%
Positive predictive value is the ability of a test to accurately determine if someone has a condition (I.e. high values are good in real life.) Sensitivity is the percentage of people who 1. Have the condition, and 2. Test positive for it. Specificity is the percentage of people who 1. Don’t have the condition, and 2. Test negative for it. PPV=(sensitivity×prevalence)/[(sensitivity×prevalence)+((1-specificity)×(1-prevalence))
Positive predictive value is the ability of a test to accurately determine if someone has a condition (I.e. high values are good in real life.) Sensitivity is the percentage of people who 1. Have the condition, and 2. Test positive for it. Specificity is the percentage of people who 1. Don’t have the condition, and 2. Test negative for it. PPV=(sensitivity×prevalence)/[(sensitivity×prevalence)+((1-specificity)×(1-prevalence))