starburst on exam questions from exam 1 & 2 Flashcards
which of the following is a nonparametric statistical test?
A) t-test for independent groups
B) ANOVA
C) sign test
D) paired t-test
C) sign test
which of the following is an example of categorical data?
A) BP
B) body weight
C) A1C
D) patient died (yes/no)
D) patient died (yes/no)
a study was conducted comparing an experimental adherence program with usual care for the treatment of dyslipidemia; patients were randomly assigned to be in one of these 2 groups. at the end of the study, the investigators found that 70% of the patients in the adherence group were at goal while only 49% of the patients in the usual care group were at goal.
What statistical group could be used to determine if the difference was statistically significant?
A) paired t-test
B) t-test for independent groups
C) chi-square
D) correlation coefficient
C) chi-square
which of the following statistical distributions is an example of nominal distribution?
A) f distribution
B) z distribution
C) binomial distribution
D) C2 distribution
B) z distribution
in a simple (bivariate) linear regression, which of the following values for the R2 correspond to the situation where all of the data points in the scatterplot lie on the regression line?
A) R2=1
B) R2=0.5
C) R2=0
D) none of these
A) R2=1
in binary logistic regression analysis, which of the following is most commonly used to conduct hypothesis tests on individual model estimates?
A) t-tests
B) f-tests
C) chi-square
D) none of these
C) chi-square
the most common level of significance used when conducting hypothesis tests in binary logistic regression is:
A) 1%
B) 5%
C) 10%
D) 20%
B) 5%
you are conducting a study and set an alpha level of 0.10. your analysis produces a p-value of 0.09. which of the following conclusions should you make?
you have reached statistical significance and reject the null hypothesis
when computing sample size using power analysis, which of the following are conventional levels for alpha and power?
A) alpha= 0.01, power= 0.80
B) alpha= 0.05, power= 0.80
C) alpha= 0.01, power= 0.20
D) alpha= 0.05, power= 0.20
B) alpha= 0.05, power= 0.80
which of the following is the expression for power?
A) beta
B) alpha
C) 1- alpha
D) 1- beta
D) 1- beta
assume your dependent variable of interest is time until event occurrence and not everyone in the sample experiences the event. which of the following is the most appropriate technique to assess relationships with this dependent variable?
A) linear regression
B) logistic regression
C) cox regression
D) none of these
C) cox regression
a common problem in many survival analyses is censoring of the data. in clinical studies, censoring may occur because:
A) the time to the events occurrence is not known exactly
B) patients drop out of the clinical study
C) some patients may not experience the event within the time frame of the study
D) all of these
D) all of these
in regression analysis, the variable that the researcher hopes to measure and explain is:
A) regressor
B) dependent variable
C) independent variable
D) explanatory variable
B) dependent variable
which of the following study designs observe study participants at only one point in time?
cross-sectional study design
in some non randomized studies, patients are assigned to certain treatment groups based on some characteristic that they possesss, which could affect the outcome of the study. this type of bias is known as
A) volunteer bias
B) contamination bias
C) selection bias
D) correlation bias
E) none of these
C) selection bias
Two pharmacists conducted a pilot study to examine the influence of follow up phone calls to patients taking medications for hypertension.
The phone calls were used to remind patients that they should take their medicine. What statistical test would the pharmacists use to determine if the mean blood pressure at the beginning of the study (baseline) was statistically significant less than the average at the end of the study (post-treatment):
paired t-test
Which of the following best describes a study which collects aggregated information from groups and compares
groups of individuals not individuals themselves?
ecological study
Which of the following best describes the extent to which observations in a study population extrapolate to the overall population of interest?
Generalizability
Which of the following study designs is best suited for assessing an exposure disease relationship when the outcome is rare and/or when the latency period involved is relatively long?
A) cross sectional
B) prospective cohort
C) retrospective cohort
D) case control
D) case control
Which of the following sampling strategies has the best possibility of selecting a representative sample from a source population?
random sampling
Which of the following is considered to be the most powerful observational designs to study causation?
cohort
Which of the following study designs determine the incidence of the outcome among exposed and unexposed groups and provide a measure of relative risk?
cohort
Which of the following is considered to be the gold standard in evaluating the safety and efficacy of an intervention?
RCT
Which of the following is the ideal research design to study a rare out-come?
case control
Which of the following studies are used for testing a hypothesis?
analytical
those where in the exposure and outcome of interest are measured at the same point in time and are used to ascess the relationship between variables of interest
cross sectional
involve comparison of exposure status among individuals with the disease or outcome of interest and those without:
case control
reflects the extent to which the clinical outcome of interest (dependent variable) in a study is caused by the treatment (independent variable):
internal validity
Pearson Correlation coefficient value for the association between the number of hours studied and the percent grade obtained on an exam was -0.82 (p=0.001). The best description of this relationship is that as the amount of study time:
increased, grades decreased
