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# Question: foundations of biostatistics and epidemiology question 1 a screening test...

###### Question details

FOUNDATIONS OF BIOSTATISTICS AND EPIDEMIOLOGY

Question 1

A screening test for bowel cancer was administered to 2,289 individuals with biopsy-proven bowel cancer and to 5,053 individuals without this cancer. The screening test was positive for 1,683 of the proven cases and 295 of the cancer free individuals. What percentage of bowel cancer cases will be correctly identified by the test?Only the final answer is needed with two decimals; units or symbols such as % are not required.

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Question 2

'Bracketing' in qualitative research means:

 a)     Researcher describes life experiences of the study participants without any preconceived ideas, bias or judgement of their own. b)     Making sure to use brackets on the calculator to get correct answer. c)     Getting incorrect answer due to not using brackets on the calculator. d)     This is something you use to jam the door or window to make sure it stays open or closed (whatever it is you are trying to do with the door or the window)!

Question 3

A unit coordinator knows that few students mix up the interpretation of p value from an assumption test as opposed to the p value from a 'hypothesis test'  which is employed to actually test the study hypothesis. P value from an assumption test will only tell us if the assumption is violated or not violated but it the p value of the actual hypothesis test that will determine our overall conclusion about the study. Anyway let's move on with the real question below:

Students studying a second year statistics unit were requested to respond to the statement 'P value scares me' with possible response options 'Always, Most of the times, Sometimes, Rarely or Never'. If the unit coordinator wants to explore whether response rankings are actually different between Internal and Fully Online students and chance is unlikely, which test should be selected for the analysis?

 a)     Wilcoxon Signed Rank Test b)     Shapiro-Wilk test c)     Mann-Whitney U test d)     Levene's test e)     Kruskal-Wallis ANOVA f)      Independent Samples t test

### Question 4

A new screening test for breast cancer was administered to 2,892 women with biopsy-proven cervical cancer and to 3,308 women without cervical cancer. The new screening test was positive for 1,744 cases of cervical cancer and falsely positive for 312 women. If someone has a positive test result what are the chances that this person actually has cervical cancer? Express your final answer as percentage with two decimals.

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Question 5

Ninety-nine university researchers attend a 3-day 'Writing Retreat' (which is basically a boot camp for writing research papers). At the conclusion of this so called Retreatthey were asked to rate their opinion for the future need and usefulness of this event. Having barely survived, only 60% responded. The response options were 'not useful, useful or very useful'. The organizers wanted to know if opinions differed between male and female attendees, in other words if opinion was contingent ongender. Which one of the following tests will be a suitable choice to test this hypothesis?

 a)     Chi Square test b)     Spearman's rho c)     Kruskal-Wallis ANOVA d)     Wilcoxon Signed Rank test e)     Independent Samples t test

Question 6

A survey done previously about pet preferences was repeated to make it more inclusive. The question in the second survey asked if participants considered themselves a 'cat person', a 'dog person' or a 'gold fish person' (surprisingly no one had any other pet preference). Results of the second survey reported majority of females considered themselves to be a 'gold fish person', males were more likely to be a 'cat person' and respondents of 'other' gender were more likely to be a 'dog person'. To explore if pet preference was associated with gender, which one of the following tests will be suitable?

 a)     Chi Square test b)     Wilcoxon Signed Rank test c)     Kruskal-Wallis ANOVA d)     Spearman's rho e)     Mann-Whitney U test

Question 7

Which one of the following is not a qualitative research design?

 a)     Phenomenology b)     Ethnography c)     Action Research d)     Ecologic design e)     Grounded Theory f)      Case Study g)     Narrative Research

### Question 8

A new screening test for bowel cancer was administered to 1,956 cases with biopsy-proven diagnosis and to 16,548 without bowel cancer. The new screening test was positive for 1,230 already diagnosed cases and also for 888 individuals who were free of bowel cancer. What percentage of disease free individuals will be correctly identified by the test? (express your answer as percentage with two decimal places)

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Question 9

A representative sample of 50 EPID students was asked to rate the importance of studying this unit from 1 to 10  (1= Not important at all to 10= Absolutely essential). After everyone provided their response rating they were shown a 10 minute video which reiterated the statistical literacy they acquired, how important it would be to evaluate any evidence as informed health professionals, how EPID1000 was going to help them survive the follow on units and  assignments they would be required to submit. After this video, students were given the option to change their previous rating if they wanted to. Surprisingly, every one took up the offer and provided a new rating. Which test will be a suitable choice if we want to investigate that ratings after watching the video changed significantly?

 a)     Spearman's rho b)     Kruskal-Wallis ANOVA c)     Wilcoxon Signed Rank test d)     Chi Square test e)     Mann-Whitney U test

Question 10

In order to assess any relationship between annual income and educational achievements when the continuous data are grossly skewed which one of the following should be used?

 a)     Spearman's rho b)     Pearson's correlation coefficient c)     Kruskal-Wallis ANOVA d)     Independent Samples t test e)     Chi Square test

Question 11

Nine health professionals are sent on an interpersonal skills training course. They are asked to rate their opinion of the need for this type of course both before and after completing the course. After attending, seven people rated the need lower than previously, one rated it higher and one person did not change his opinion. What test could be used to assess whether the difference in rankings before and after the course is statistically significant or any observed difference is only a play of random chance?

 a)     Kruskal-Wallis ANOVA b)     Wilcoxon Signed Rank test c)     Mann-Whitney U test d)     Chi Square test e)     Paired Samples t test

Question 12

In an RCT for a new antihypertensive drug, the study subjects were randomized into three groups after baseline measurements; group A to receive high dose of the new drug, group B to receive low dose of the new drug and third group C to receive current drug. Average BP was recorded at the end of the trial for all three groups but the positive skew in the DV did not go away even after transformation. Which one of the following is a good option:

 a)     Proceed with the non parametric test b)     It does whatever you ask for so let SPSS do its thing. c)     This is a good excuse for not having to do anything further so proceed with some rest and relaxation. d)     Proceed with the parametric test, no one will find out anyway.

Question 13

Wilcoxon Signed Rank test is used for:

 a)     Two related samples with at least scale data b)     Two unrelated samples with at least scale data c)     Two related samples with at least Ordinal data d)     None of the options are actually correct for using this test. e)     Two unrelated samples with at least Ordinal data

Question 14

Four different groups of students were classified according to the location at the time of answering the question "Do you know the meaning of life"? Four locations were library, tavern, computing labs and walkways. The respondents had to choose a number from 1 to 5 (1=none of it and 5=all of it). Which test will be suitable for analysis to investigate if response ratings differed significantly between at least two groups.

 a)     Mann-Whitney U test b)     Wilcoxon Signed Rank test c)     Independent Samples t test d)     Kruskal-Wallis ANOVA e)     One-way ANOVA

Question 15

A random group of students was asked if they were a 'cat person' or a 'dog person' and excluded those who were neither. After the data analysis results showed that females were more likely to be a 'dog person' while males were more likely to be a 'cat person'. Results were surprising, no doubt, but hopefully you can identify correctly which test was used  for the analysis?

 a)     Kruskal-Wallis ANOVA b)     Mann-Whitney U test c)     Chi Square test d)     Wilcoxon Signed Rank test e)     Spearman's rho