Hypothesis Testing and Variable Types Quiz
68 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What effect would raising the cutoff score for a screening test have on the positive predictive value?

  • It would decrease (correct)
  • It would remain unchanged
  • It would fluctuate
  • It would increase

In a population where the prevalence of the disease in question is low, what impact would this have on the positive predictive value of a screening test?

  • It would remain unchanged
  • It would decrease (correct)
  • It would increase
  • It would fluctuate

If the cutoff score for a screening test is lowered, what impact would this have on the positive predictive value?

  • It would remain unchanged
  • It would fluctuate
  • It would increase (correct)
  • It would decrease

What measure of association would be most appropriate to calculate in this scenario?

<p>Odds ratio (B)</p> Signup and view all the answers

What is the impact of raising the cutoff score for a screening test on the sensitivity of the test?

<p>It decreases (D)</p> Signup and view all the answers

What test would be most suitable to test the statistical significance of the association?

<p>Chi-square test (A)</p> Signup and view all the answers

In which scenario would you expect the positive predictive value of a screening test to be higher?

<p>In a population with high disease prevalence (A)</p> Signup and view all the answers

What would be the null hypothesis in this scenario?

<p>There is no association between exposure and outcome (C)</p> Signup and view all the answers

What is one advantage of conducting a case-control study rather than a cohort study in this scenario?

<p>Less prone to recall bias (A)</p> Signup and view all the answers

Why would there be difficulty in concluding a causal relationship in this study, even if a strong association is found between administration of the measles vaccine and preterm births?

<p>Potential confounding factors (D)</p> Signup and view all the answers

What type of test did the researchers use to study the association and reject the null hypothesis?

<p>Chi-square test (D)</p> Signup and view all the answers

Which variable type is used for labeling theatre-goers as youth, regular adult, or seniors?

<p>Nominal (D)</p> Signup and view all the answers

Which variable type is used for coding UW students as '0' if an undergraduate student or '1' if a graduate student?

<p>Dichotomous/Binary (B)</p> Signup and view all the answers

What analytical plan would be suitable for knowing the mean difference in hospital charges between persons with and without Medicaid?

<p>Two-sample t-test (A)</p> Signup and view all the answers

How would you decide whether you can reject the null hypothesis in the context of analyzing hospital charges between persons with and without Medicaid?

<p>By comparing p-values to the significance level (C)</p> Signup and view all the answers

What is the sensitivity of the ELISA test for detecting HIV antibody?

<p>94.0% (A)</p> Signup and view all the answers

What type of study design would be most appropriate for investigating the association between preterm births and the measles vaccine?

<p>Case-control study (A)</p> Signup and view all the answers

What is the specificity of the ELISA test for detecting HIV antibody?

<p>98.0% (D)</p> Signup and view all the answers

In which study design is the study sample selected on the basis of outcome status?

<p>Case-control study (A)</p> Signup and view all the answers

What is the actual prevalence of HIV antibody in the hypothetical patient population?

<p>1.0% (A)</p> Signup and view all the answers

Which study design would be most suitable for studying the incidence rate of a disease in the exposed and non-exposed?

<p>Cohort study (B)</p> Signup and view all the answers

What are false positives in the context of screening for HIV antibody using the ELISA test?

<p>Individuals who do not have HIV antibody but are incorrectly identified as positive by the test (A)</p> Signup and view all the answers

In which study design are the results especially prone to recall bias?

<p>Case-control study (D)</p> Signup and view all the answers

What are false negatives in the context of screening for HIV antibody using the ELISA test?

<p>Individuals who have HIV antibody but are incorrectly identified as negative by the test (A)</p> Signup and view all the answers

Which study design involves randomly assigning participants to either be exposed to a treatment or not exposed?

<p>Neither (A)</p> Signup and view all the answers

What is the significance of the confidence interval not including 0?

<p>It indicates a statistically significant result (D)</p> Signup and view all the answers

When reporting the median as the measure of central tendency, what should also be reported?

<p>Interquartile range (A)</p> Signup and view all the answers

What type of graph is typically used to depict a distribution?

<p>Histogram (D)</p> Signup and view all the answers

Which statements about the distribution in the histogram are true?

<p>It is right skewed (A)</p> Signup and view all the answers

Which measures of central tendency and spread would be best to report for the variable depicted in the histogram?

<p>Median and interquartile range (D)</p> Signup and view all the answers

What does it mean if the confidence interval around the mean difference includes zero?

<p>The result is not statistically significant (D)</p> Signup and view all the answers

What is the prevalence of anti-social behaviors at the time of study enrollment?

<p>40% (A)</p> Signup and view all the answers

Can the incidence of anti-social behaviors during the study period (9th-12th grade) be calculated?

<p>Yes, it can be calculated (C)</p> Signup and view all the answers

What is the main strength of a screening tool with high specificity but low sensitivity?

<p>It minimizes false positives (A)</p> Signup and view all the answers

What is a key limitation of a screening tool with low sensitivity?

<p>It may generate many false negatives (D)</p> Signup and view all the answers

What would be a recommended implementation for a screening tool with high specificity but low sensitivity in elementary schools?

<p>Use it as an initial broad screening tool and follow up with more sensitive tests for positive cases (B)</p> Signup and view all the answers

What does the sensitivity of a screening test measure?

<p>The proportion of positive tests that are truly positive. (C)</p> Signup and view all the answers

Which factor leads to a marked increase in the positive predictive value of a test?

<p>Higher prevalence in the screened population (D)</p> Signup and view all the answers

Which term refers to the ability of a test to identify correctly those who do not have the disease?

<p>Specificity (C)</p> Signup and view all the answers

What does the negative predictive value measure?

<p>The proportion of negative tests that are truly negative. (B)</p> Signup and view all the answers

Which factor determines the positive predictive value of a test?

<p>The prevalence of the disease in the population tested (A)</p> Signup and view all the answers

What does specificity measure for a screening test?

<p>The proportion of negative tests that are truly negative. (C)</p> Signup and view all the answers

Which is true about Positive Predictive Value (PPV)?

<p>PPV increases with a higher prevalence in the screened population. (C)</p> Signup and view all the answers

What does the null hypothesis (Ho) in hypothesis testing typically state?

<p>There is no difference, effect, or association (C)</p> Signup and view all the answers

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

<p>Researchers' ideas to be proven (C)</p> Signup and view all the answers

What is the significance level (α) used for in hypothesis testing?

<p>To decide the rejection region (C)</p> Signup and view all the answers

What is the primary purpose of the rejection region in hypothesis testing?

<p>To decide the statistical significance (A)</p> Signup and view all the answers

In hypothesis testing, what is the primary purpose of the z-tabulated value?

<p>To decide significance (C)</p> Signup and view all the answers

What is the alternative hypothesis (Ha) in Case 1 of the provided examples?

<p>Well water at the fair was the risk factor/source of diarrheal disease. (D)</p> Signup and view all the answers

What is the null hypothesis (Ho) in Case 3 of the provided examples?

<p>Mean birthweight in counties implemented starting right is equal with the mean weight birthweight in non-starting right implemented counties. (B)</p> Signup and view all the answers

What does the significance level (α) typically represent?

<p>(1-confidence level) (C)</p> Signup and view all the answers

What is the definition of Incidence Rate?

<p>The number of new cases of a disease that occur in a population at risk per person-time of observation (C)</p> Signup and view all the answers

What is the Bathtub Analogy used to illustrate?

<p>The relationship between prevalence and incidence (D)</p> Signup and view all the answers

What is the key measure used in screening tests to correctly identify those who have the disease?

<p>Sensitivity (C)</p> Signup and view all the answers

What does a true negative (TN) represent in the context of screening tests?

<p>People who do not have the disease and have a negative test result (A)</p> Signup and view all the answers

What does the positive predictive value (PPV) measure in screening tests?

<p>The proportion of true positives out of all those with a positive test result (A)</p> Signup and view all the answers

What impact does raising the cutoff score for a screening test have on sensitivity?

<p>Decreases sensitivity (C)</p> Signup and view all the answers

What represents a false positive (FP) in the context of screening tests?

<p>People who have a positive test result but do not have the disease (B)</p> Signup and view all the answers

What is the key goal of using screening tests?

<p>To reduce morbidity and mortality (D)</p> Signup and view all the answers

What does a Relative Risk (RR) value greater than 1 indicate?

<p>Higher incidence of disease in the exposed group (B)</p> Signup and view all the answers

How is the Relative Risk (RR) interpreted when it equals 1?

<p>No association, or no difference in incidence of disease between the two exposure groups (A)</p> Signup and view all the answers

In the context of Relative Risk (RR), what does it mean if non-smokers have '1.6 times less risk' of developing CHD than smokers?

<p>Non-smokers have a lower risk compared to smokers (D)</p> Signup and view all the answers

What is the interpretation of a Relative Risk (RR) value less than 1?

<p>Lower incidence of disease in the unexposed group (C)</p> Signup and view all the answers

What would be the most suitable interpretation of a Relative Risk (RR) value equal to 1?

<p>No association, or no difference in incidence of disease between the two exposure groups (A)</p> Signup and view all the answers

According to the measure of association, what does a numerator of 'Risk of disease in exposed' represent?

<p>People at risk of developing a disease and exposed to a specific factor (B)</p> Signup and view all the answers

In the context of Relative Risk (RR), what does a denominator of 'Risk of disease in unexposed' represent?

<p>People at risk of developing a disease but not exposed to any factor (A)</p> Signup and view all the answers

How would you interpret a Relative Risk (RR) value equal to 1?

<p>'No difference between exposed and unexposed groups' (D)</p> Signup and view all the answers

'Smokers have a 1.6 times greater risk of developing CHD than non-smokers'. What is the inverse true statement?

<p>'Non-smokers have 60% decreased risk of CHD compared to smokers' (C)</p> Signup and view all the answers

More Like This

Research Hypothesis Testing Methods
30 questions
Designing Research Methods: Part 2
18 questions
Statistics: Types of Variables and Testing
18 questions
Use Quizgecko on...
Browser
Browser