PUB561 UPDATED ACTUAL Questions and
CORRECT Answers
matched case-control study - CORRECT ANSWER -To investigate the relationship between egg
consumption and heart disease, a group of patients admitted to hospital with myocardial infarction were
questioned about their egg consumption. A group of age and sex matched patients admitted to a fracture
clinic were also questioned about their egg consumption using an identical protocol. What study design is
this?
cohort study - CORRECT ANSWER -to investigate the relationship between certain solvents and
cancer, all employees at a factory were questioned about their exposure to an industrial solvent, and the
amount and length of exposure measured. These subjects were regularly monitored, and after 10 years a
copy of the death certificate for all those who had died was obtained. What type of study design is this?
cross-sectional study - CORRECT ANSWER -A survey was conducted of all nurses employed at a
particular hospital. Among other questions, the questionnaire asked about the grade of the nurse and
whether he/she was satisfied with their career prospects. What type of study design is this?
Quasi experimental Design - CORRECT ANSWER -A new triage system has been set up at the
local Accident and Emergency Unit. To evaluate the new system, the waiting times of patients were
measured for 6 months and compared with the waiting times a a comparable nearby hospital. What type
of study design is this?
Researcher/investigator selects the treatment arm (intervention or control) using a random number
generator and clinical staff are not told of allocation (double blind study) - CORRECT ANSWER -
What is the most appropriate way to randomise participants in a randomised controlled trial?
b. number of cases in each variable - CORRECT ANSWER -Which of the following is not an
essential part of a coding manual.
a. Name of survey and date or version control
b. Number of cases in each variable
c. Range of expected responses
d. Definition of variables
,d. Re-enter data from 500 of the surveys and compare the new datafile for the subset of surveys to the
original data file containing information from all surveys - CORRECT ANSWER -You have
conducted a 10-question survey of 5000 people using paper survey forms. Unfortunately you spent most
of your time and budget on collecting as many responses as possible leaving you very limited resources
(time and money) to analyse the data. What would be the best way to ensure your data entry is accurate?
a. Individually check each survey against the data file
b. Don't worry about it because your typing skills are good and there were only 10 questions on the
survey anyway.
c. Double data entry of all surveys
d. Re-enter data from 500 of the surveys and compare the new datafile for the subset of surveys to the
original data file containing information from all surveys
Parametric - CORRECT ANSWER -inferential statistical tests involving MEANS AND
VARIANCE to describe probability distribution of NORMAL distrabution.
Central Limit Theorem (CLT) - CORRECT ANSWER -the sampling distribution derived from a
simple random sample will be approximately normally distributed if you take the mean of many samples
within the original sample
As sample size increase 3 things occure,they are:
(which is basically the central limiting theorem- that even if the data is not normally distributed, the
means of the smaller sample sizes taken from the distribution will be!) - CORRECT ANSWER -1)
as sample size increase the Standard error decreases (standard error is the uncertainitay or variability of
the populion mean)
2) The larger the sample, the clsoer to the population mean.
3) The sample means will be noramlly distributed in histograms frequency polygons.
Standard Error of the Mean - CORRECT ANSWER -refers to the uncertain/variability of the
POPULATION mean (not sample mean)
Standard Deviation (SD) - CORRECT ANSWER -uncertain of the sample being onserved.
,A measure of variability that indicates the average difference between the scores and their mean.
Hypothesis - CORRECT ANSWER -always come in a pair and most cover every possible outcome.
Null Hypothesis (H0) - CORRECT ANSWER -A statement of "no difference." The result shows
nothing s happening
Alternative Hypothesis (H1 or H2) - CORRECT ANSWER -the hypothesis that a proposed result is
possible for the population. HYPOTHESIS that something is happening.
two-tailed hypothesis - CORRECT ANSWER -predicts a CHANGE and or relationship between
two variables but does not specify the direction of the change/relationship. Does not specify lower or
higher
*used more often as they are more conservative.
One-tailed hypothesis - CORRECT ANSWER -only one DIRECTION specified of an effect or
relationship is predicted in the alternative hypothesis of the test. Either lower or higher.
example HYPOTHESIS
one or two-tailed? null or alternative?
The new drug does not change blood pressure - CORRECT ANSWER -no direction- two-tailed
No change- NULL
example HYPOTHESIS
one or two-tailed? null or alternative?
The new drug does decrease blood pressure - CORRECT ANSWER -one tailed- as its one direction
Alternative hypothesis-as there is a change
example HYPOTHESIS
one or two-tailed? Null or alternative?
, The new drug changes blood pressure - CORRECT ANSWER -two-tailed- any direction
Alternative
hypothesis testing 6 steps - CORRECT ANSWER -1) State null
2) collect data
3)Summarise data (graphs)
What data look like if the null hypothesis was true -> expected ata
5) calcullate discrepancy between groups (or magnitude of association) - test statisitic
6) MAKE DECISION (REJECT OR ACCEPT) AND COCLUSION
small p-value - CORRECT ANSWER -reject the null hypothesis
-meaning the observed data would be unlikly if the null hypothesis were true
statistical significance - CORRECT ANSWER -The condition that exists when the probability that
the observed findings are due to chance is very low.
p-value - CORRECT ANSWER --The probability of observing the data if the null hypothesis is true
-The probability level which forms basis for deciding if results are statistically significant (not due to
chance).
clinical significance - CORRECT ANSWER -degree to which research findings have useful and
meaningful applications to real problems
confound - CORRECT ANSWER -
hypothesis writting: when testing continous and continous variables - CORRECT ANSWER -1)
Correlation & coeffiencent
2) linear regression (increase decrease ect -one tailed)
CORRECT Answers
matched case-control study - CORRECT ANSWER -To investigate the relationship between egg
consumption and heart disease, a group of patients admitted to hospital with myocardial infarction were
questioned about their egg consumption. A group of age and sex matched patients admitted to a fracture
clinic were also questioned about their egg consumption using an identical protocol. What study design is
this?
cohort study - CORRECT ANSWER -to investigate the relationship between certain solvents and
cancer, all employees at a factory were questioned about their exposure to an industrial solvent, and the
amount and length of exposure measured. These subjects were regularly monitored, and after 10 years a
copy of the death certificate for all those who had died was obtained. What type of study design is this?
cross-sectional study - CORRECT ANSWER -A survey was conducted of all nurses employed at a
particular hospital. Among other questions, the questionnaire asked about the grade of the nurse and
whether he/she was satisfied with their career prospects. What type of study design is this?
Quasi experimental Design - CORRECT ANSWER -A new triage system has been set up at the
local Accident and Emergency Unit. To evaluate the new system, the waiting times of patients were
measured for 6 months and compared with the waiting times a a comparable nearby hospital. What type
of study design is this?
Researcher/investigator selects the treatment arm (intervention or control) using a random number
generator and clinical staff are not told of allocation (double blind study) - CORRECT ANSWER -
What is the most appropriate way to randomise participants in a randomised controlled trial?
b. number of cases in each variable - CORRECT ANSWER -Which of the following is not an
essential part of a coding manual.
a. Name of survey and date or version control
b. Number of cases in each variable
c. Range of expected responses
d. Definition of variables
,d. Re-enter data from 500 of the surveys and compare the new datafile for the subset of surveys to the
original data file containing information from all surveys - CORRECT ANSWER -You have
conducted a 10-question survey of 5000 people using paper survey forms. Unfortunately you spent most
of your time and budget on collecting as many responses as possible leaving you very limited resources
(time and money) to analyse the data. What would be the best way to ensure your data entry is accurate?
a. Individually check each survey against the data file
b. Don't worry about it because your typing skills are good and there were only 10 questions on the
survey anyway.
c. Double data entry of all surveys
d. Re-enter data from 500 of the surveys and compare the new datafile for the subset of surveys to the
original data file containing information from all surveys
Parametric - CORRECT ANSWER -inferential statistical tests involving MEANS AND
VARIANCE to describe probability distribution of NORMAL distrabution.
Central Limit Theorem (CLT) - CORRECT ANSWER -the sampling distribution derived from a
simple random sample will be approximately normally distributed if you take the mean of many samples
within the original sample
As sample size increase 3 things occure,they are:
(which is basically the central limiting theorem- that even if the data is not normally distributed, the
means of the smaller sample sizes taken from the distribution will be!) - CORRECT ANSWER -1)
as sample size increase the Standard error decreases (standard error is the uncertainitay or variability of
the populion mean)
2) The larger the sample, the clsoer to the population mean.
3) The sample means will be noramlly distributed in histograms frequency polygons.
Standard Error of the Mean - CORRECT ANSWER -refers to the uncertain/variability of the
POPULATION mean (not sample mean)
Standard Deviation (SD) - CORRECT ANSWER -uncertain of the sample being onserved.
,A measure of variability that indicates the average difference between the scores and their mean.
Hypothesis - CORRECT ANSWER -always come in a pair and most cover every possible outcome.
Null Hypothesis (H0) - CORRECT ANSWER -A statement of "no difference." The result shows
nothing s happening
Alternative Hypothesis (H1 or H2) - CORRECT ANSWER -the hypothesis that a proposed result is
possible for the population. HYPOTHESIS that something is happening.
two-tailed hypothesis - CORRECT ANSWER -predicts a CHANGE and or relationship between
two variables but does not specify the direction of the change/relationship. Does not specify lower or
higher
*used more often as they are more conservative.
One-tailed hypothesis - CORRECT ANSWER -only one DIRECTION specified of an effect or
relationship is predicted in the alternative hypothesis of the test. Either lower or higher.
example HYPOTHESIS
one or two-tailed? null or alternative?
The new drug does not change blood pressure - CORRECT ANSWER -no direction- two-tailed
No change- NULL
example HYPOTHESIS
one or two-tailed? null or alternative?
The new drug does decrease blood pressure - CORRECT ANSWER -one tailed- as its one direction
Alternative hypothesis-as there is a change
example HYPOTHESIS
one or two-tailed? Null or alternative?
, The new drug changes blood pressure - CORRECT ANSWER -two-tailed- any direction
Alternative
hypothesis testing 6 steps - CORRECT ANSWER -1) State null
2) collect data
3)Summarise data (graphs)
What data look like if the null hypothesis was true -> expected ata
5) calcullate discrepancy between groups (or magnitude of association) - test statisitic
6) MAKE DECISION (REJECT OR ACCEPT) AND COCLUSION
small p-value - CORRECT ANSWER -reject the null hypothesis
-meaning the observed data would be unlikly if the null hypothesis were true
statistical significance - CORRECT ANSWER -The condition that exists when the probability that
the observed findings are due to chance is very low.
p-value - CORRECT ANSWER --The probability of observing the data if the null hypothesis is true
-The probability level which forms basis for deciding if results are statistically significant (not due to
chance).
clinical significance - CORRECT ANSWER -degree to which research findings have useful and
meaningful applications to real problems
confound - CORRECT ANSWER -
hypothesis writting: when testing continous and continous variables - CORRECT ANSWER -1)
Correlation & coeffiencent
2) linear regression (increase decrease ect -one tailed)
