EBCR 3 exam

You’re reading a study that is evaluating the effect of different vitamin supplements on the development of colon cancer. The independent variable is _________ and the dependent variable is ___________

Vitamin supplements; colon cancer

In the study from KC #1, data on the use of vitamin supplements (VS) is divided into “never taken”, “taken 1-10 days/month”, “taken 11-20 days/month”, or “taken >20 days/month”. The development of colon cancer (CC) over the study period is classified as “yes” or “no”. VS is best described as a ____ variable and CC is best described as a _____ variable.

Ordinal, nominal

Which measure of central tendency is the most sensitive to outliers in the data?

Mean

When data is arranged in numeric order, the middle 50% of data values is called the

The interquartile range

A frequency distribution that contains data values which are much higher than the mean (“outliers”) is

Right skewed

An investigator would like to compare Drug A (new) to Drug B (standard of care) in the treatment of rheumatoid arthritis. The null hypothesis for this study is:

Drug A is no different than Drug B

An investigator, Dr. Z, would like to compare Drug A (new) to Drug B (standard of care) in the treatment of lung cancer. Alpha is 0.05 and beta is 0.20. Dr. Z would like to detect a 20% difference n the response rate between A and B. What is the likelihood of concluding there is a difference when there really isn’t one?

5%

Dr. Z completes the study and the statistical test results in a p value of 0.03. What is the correct interpretation of this p value?

The probability of observing the study results is 3% if Ho is true

Dr. Z completes the study and the statistical test results in a p value of 0.03.

True/False: The results are statistically significant and Ho can be rejected.

true

Dr. P completes a study comparing the difference in the mean change in pain scores in patients treated with acupuncture vs. those enrolled in yoga program.

At the end of the study, the difference in the mean change was 3.6 (95% confidence interval -2.8 to +5.9)Were the results statistically significant?

no

Your PLRP group will be doing a chart review study to evaluate the incidence of hepatotoxicity of a new antibiotic recently approved for children hospitalized for meningitis. You will compare this to the standard antibiotic used.

Your PLRP mentor asks what statistical test you will use to analyze your results.

Which of the following tests is the correct choice?

Chi-square

During a journal club presentation, your APPE preceptor asks about the appropriate statistical test that should be used when evaluating the difference in pain scores

before and after a group of patients are given a new combination opioid and NSAID analgesic.

Wilcoxan signed rank test

You’re preparing for a journal club presentation for a study assessing the mean change in cholesterol in 3 different groups of patients.

Results show: A=12 mg/dl, B=16mg/dl, C=24mg/dl). An ANOVA test was used to evaluate the results. The p value is less than a so you can conclude a statistically

significant result.

The appropriate conclusion based on the ANOVA test is:

One of the groups is different from at least one of the other groups