Medical Screening Test Metrics

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What is the consequence if the p-value is greater than the alpha level?

We fail to reject the null hypothesis (correct)

We cannot make a conclusion

We reject the null hypothesis

We accept the null hypothesis

What type of error occurs when the null hypothesis is true but rejected?

Type III error

Type II error

Type IV error

Type I error (correct)

In hypothesis testing, what does a confidence interval not including the null value indicate?

We reject the null hypothesis (correct)

There is a Type II error

We accept the null hypothesis

We fail to reject the null hypothesis

What is the consequence if the p-value is less than the alpha level?

We reject the null hypothesis Signup and view all the answers

What happens if a Type II error occurs in hypothesis testing?

The null hypothesis is accepted Signup and view all the answers

What is the purpose of the null hypothesis (Ho) in hypothesis testing?

To provide a formalized skepticism and assume no difference, effect, or association until evidence proves otherwise Signup and view all the answers

In the context of hypothesis testing, what does the alternative hypothesis (Ha) represent?

The complementary proposition to the null hypothesis (Ho) being tested Signup and view all the answers

Which of the following best represents a null hypothesis (Ho) for the given Case 3 example?

Mean birthweight in counties implemented starting right is equal with the mean weight birthweight in non-starting right implemented counties Signup and view all the answers

What is the significance level (α) for a 95% confidence level in hypothesis testing?

0.05 Signup and view all the answers

How is the rejection region used in determining statistical significance in hypothesis testing?

To decide if the null hypothesis should be rejected based on the test statistics Signup and view all the answers

What is a major limitation of cross-sectional studies?

They cannot establish temporal relationship Signup and view all the answers

Why are case-control studies useful for rare outcomes?

Because they can calculate odds ratio directly Signup and view all the answers

What is a limitation of case-control studies?

They cannot estimate risk Signup and view all the answers

Why is it hard for cross-sectional studies to establish temporal relationships?

Due to the difficulty in determining if exposure came before the outcome Signup and view all the answers

What type of study design would be most appropriate for identifying risk factors needing urgent attention?

Cross-sectional study Signup and view all the answers

Which test is used to determine if all the means of different categories are equal to each other?

ANOVA Signup and view all the answers

What does a chi-square test determine?

Association between categorical variables Signup and view all the answers

When is a two-sample t test used?

When the independent variable is a binary variable Signup and view all the answers

What does correlation (r) measure?

Association between continuous variables Signup and view all the answers

What do relative risk (RR) and odds ratio (OR) measure?

Difference in proportions Signup and view all the answers

What is the 'null value' for measures like RR and OR?

1 Signup and view all the answers

If a confidence interval for a Relative Risk (RR) spans the value of 1, what can be concluded about its statistical significance?

It is not statistically significant Signup and view all the answers

What does it mean if the p-value is less than 0.05 in hypothesis testing?

The null hypothesis is rejected Signup and view all the answers

What test would you use to compare two sample proportions to each other?

Two-sample z test Signup and view all the answers

In a one-sample z test, what does the independent variable represent?

A constant Signup and view all the answers

What does Sensitivity measure in a screening test?

The proportion of positive tests that are truly positive Signup and view all the answers

What does Specificity measure in a screening test?

The proportion of negative tests that are truly negative Signup and view all the answers

What does Positive Predictive Value (PPV) measure?

The proportion of positive tests that are truly positive Signup and view all the answers

What is a determinant of Positive Predictive Value (PPV)?

The prevalence of disease in the population tested Signup and view all the answers

What does Negative Predictive Value (NPV) measure?

The proportion of negative tests that are truly negative Signup and view all the answers

What is the main advantage of a cohort study design?

It is the only design that can establish a temporal relationship between exposure and outcome Signup and view all the answers

What distinguishes a case-control study from a cohort study?

Case-control studies focus on comparing incidence of disease in exposed and unexposed groups Signup and view all the answers

In an outbreak investigation, what can the shape of an epidemic curve help us understand?

Trends and clues about the source of the outbreak Signup and view all the answers

Which study design provides stronger evidence as you move up the pyramid of evidence?

Cohort studies Signup and view all the answers

What is a key component of outbreak investigations?

Developing case definitions and using epidemic curves Signup and view all the answers

Why are cohort studies particularly useful for investigating rare exposures?

They allow for following individuals over time to assess outcomes Signup and view all the answers

What type of study design focuses on comparing the incidence of disease in exposed and unexposed groups?

Case-control study Signup and view all the answers

In an outbreak investigation, what distinguishes confirmed from suspected cases?

The certainty about whether the individual has the disease Signup and view all the answers

What does the shape of an epidemic curve primarily help to understand during an outbreak investigation?

The trends and clues about the source of the outbreak Signup and view all the answers