Statistical Tests
If you would like to compare the blood pressure before and after drinking three cups of coffee, which test would be the most appropriate?
A. Student t- test
B. Paired t-test
C. Chi-squared test
B. Paired t-test
What type of bias results when subjects are reluctant to report an exposure due to their personal beliefs?
A. Selection
B. Surveillance
C. Reporting
C. Reporting
Which of the following is correct regarding the specificity of a test for medical diagnosis?
A. Specificity refers to the probability the test is negative when the disease is not present
B. Specificity refers to the probability the test is positive when the disease is present
C. Specificity refers to the probability the test is positive when the disease is not present
A. Specificity refers to the probability the test is negative when the disease is not present
The Framingham study is what type of study?
A. Cohort
B. RCT
C. Case-control
A. Cohort
If you are recording temperature on the Fahrenheit or Celsius scale, which type of data are you using?
A. Nominal
B. Ordinal
C. Interval
C. Interval
Which of the following tests does ANOVA use?
A. Paired t-test
B. Wilcoxon signed rank test
C. F-test
C. F-test
Which type of bias is most common in meta-analysis studies?
A. Response bias
B. Attrition bias
C. Publication bias
C. Publication bias
In order for calculation of disease incidence to be meaningful, what must be true of any individual included in the denominator?
A. The individual has the potential to develop the disease
B. The individual has previously developed the disease
C. The individual has been exposed to someone with the disease
A. The individual has the potential to develop the disease
In a clinical trial comparing ibuprofen to naproxen for menstrual cramping, group 1 receives ibuprofen and group 2 receives naproxen for 12 weeks. Following a period for a week, group 1 then receives naproxen and group 2 receives ibuprofen for 12 weeks. Which clinical design is demonstrated by this trial?
A. Masking
B. Crossover
C. RCT
B. Crossover
The Kelvin scale is an example of what type of variable?
A. Ordinal
B. Interval
C. Ratio
C. Ratio
An epidemiologist would like to compare the heart rate of 10 men and 10 women with the Zika virus. Which of the following tests is best suited to compare the non-parametric medians of the 2 groups?
A. Chi-square
B. Mann-Whitney U test
C. Multiple regression
B. Mann-Whitney U test
Nondifferential misclassification most often has which effect on the relative risk?
A. No effect
B. Increase
C. Shift to 1.0
C. Shift to 1.0
A. It is always qualitative
B. It is presented on a rating scale
C. It involves mutually exclusive levels
C. It involves mutually exclusive levels
What is the disadvantage of a retrospective cohort study?
A. It is more expensive than a prospective cohort study
B. Misclassification of exposure is a common problem
C. It takes a long time to complete
B. Misclassification of exposure is a common problem
If the distribution is skewed to the right, what can be said about the mean, median and mode?
A. Mean=Median=Mode
B. Mean<Median<Mode
C. Mean>Median>Mode
C. Mean>Median>Mode
Which following test is the nonparametric counterpart of ANOVA?
A. Kruskal-Wallis
B. Mann-Whitney U test
C. Spearman rank correlation coefficient
A. Kruskal-Wallis
A physician is surveying the incidence of disease B and disease C. She concludes that disease C has a higher incidence than disease B. It is later found that the 2 diseases have the same incidences, and that disease B has a much faster disease onset leading to mortality. What is this phenomenon called?
A. Length bias
B. Lead-time bias
C. Incidence bias
A. Length bias
What is the best way to show precision in estimation of the population mean?
A. SD
B. SEM
C. Coefficient of variation
B. SEM
Which of the following research designs is not observational?
A. Retrospective cohort
B. RCT
C. Cross-sectional
B. RCT
Which measures of central tendency is heavily influenced by the outlier?
A. Mean
B. Mode
C. Median
A. Mean
The Wilcoxon signed rank test is the nonparametric equivalent of which of the following tests?
A. Student t-test
B. Paired t-test
C. Chi-squared
A. Student t-test
A new screening test is applying for FDA approval. The owners of the test that they increase the survival in patients with pancreatic cancer. Their studies show by diagnosing it 6 months earlier than any other test, they can increase the length of survival of the disease.
The FDA approval panel responds that this test has this type of bias?
A. Misclassification
B. Lead-time
C. Length
B. Lead-time
It is appropriate to use the Fisher's exact test when which of the following tests does not meet the necessary criteria?
A. ANCOVA
B. Chi-square
C. Likelihood ratio
B. Chi-square
Which of the following is used for confounding primarily used in the analysis stage?
A. Matching
B. Stratification
C. Hypothesis testing
B. Stratification
As the number of subjects increases, which of the following is always true?
A. The number needed to treat increases
B. The CI becomes smaller
C. The power of the study decreases
B. The CI becomes smaller