Research 2 Final Flashcards
WEEK 1
WEEK 1
_______ research is an applied research conducted on human subjects focused on testing theories to help find better ways to detect, diagnose, treat, and prevent disease or develop therapies.
Clinical
What are the 5 steps of the clinical research process?
- ) Research question formulation
- ) Study design
- ) Study implementation
- ) Data analysis
- ) Disseminate findings
What are the 3 types of clinical research and what are they used for?
- ) Descriptive - Describe Populations
- ) Exploratory - Find Relationships
- ) Explanatory - Cause and Effect
What are 2 types of Descriptive clinical research?
- Case report studies
- Descriptive studies
What are 2 types of Exploratory clinical research?
- Cohort studies
- Case-control studies
What is a type of Explanatory clinical research?
-RCT
Data levels of measurement are majorly __________ or _________.
continuous or categorical
Data can be distributed __________ or ________ to the right/left.
normally or skewed right/left
Continuous data are described using the _____;______ and the _________;____ graph.
- mean; SD
- histogram; line graph
Categorical data are described using the _________;________ and the _____;_____ graph.
- frequency; proportion
- pie chart; bar graph
_____________ is performed to make inference about the population group based on the sample group and its result produces _________ that is useful for interpretation.
- Statistical Hypothesis Testing
- p-value
In SHT what is;
- Type I Error?
- Type II Error?
- Power?
- Type I Error = probability of falsely rejecting the null hypothesis (false positive)
- Type II Error = probability of falsely retaining the null hypothesis (false negative)
- Power = the probability of correctly rejecting the null hypothesis
______________ is constructed around a statistic to make inference about the population group based on the sample group. For interpretation it is checked if it contains a null value of 0 for mean difference and 1 for ratio.
Confidence Interval (CI)
- _____________ is an appropriate SHT for the two independent groups comparison of the mean.
- ______ is an appropriate SHT for the multiple independent groups comparison of the means.
- _____________ is an appropriate SHT for any number of groups comparison of the proportions/ratio.
- students t-test
- ANOVA
- Chi-square
WEEK 2
WEEK 2
- ________ is one of the most popular methods for collecting descriptive or subjective data.
- __________ is a structured survey, self-administered, using pen / paper or electronic formats.
- Survey
- Questionnaire
- For a survey questionnaire, _____-______ questions are useful for asking subjective opinions.
- For a survey questionnaire, ____-______ questions are useful for easy coding and these must be exhaustive and mutually exclusive
- open-ended
- close-ended
- _______ _________ is a research design that uses explicit methods to identify, select, appraise and synthesize results from similar but separate studies.
- ______-_______ is a statistical method of combining a large collection of results from individual studies.
- Systematic review
- Meta-analysis
_____________ presents meta-analysis results.
Forests plot
_________________ is the place to find independent, high quality evidence of systematic review.
Cochrane library
WEEK 3
WEEK 3
Are most measurements directly observable?
No, named indirect nature of measurement.
Measure for a research study can be appropriately selected by considering what psychometric properties?
- Reliability
- Validity
- Scale of Measurement
- Self report vs performance based measure
- MDC
- Clinical utility of the measures
- _________ is consistency time after time, with as little variation as possible.
- ________ is accuracy that a test is measuring what it is intended to measure.
- Reliability
- Validity
What are the types of reliability?
- Test-retest
- Intrarater
- Interrater
- Internal Consistency
What are the types of validity?
- Face
- Content
- Construct
-Reliability can be estimated using ___________ ___________ for two continuous measurements and __________________ for two categorical measurements
- correlation coeffecient (r)
- Cohen’s kappa (k)
Internal consistency reliability can be estimated using _____________.
Cronbach’s alpha
Construct validity can be estimated using ___________, __________________, and _________________.
- correlation
- confirmatory factor analysis
- cluster analysis
WEEK 4
WEEK 4
Data level of measurement can be either ____________ or _____________.
continuous or categorical
- For continuous data, its distribution can be visualized by drawing a _________ to check whether the data are distributed to be symmetric or skewed.
- For continuous data whose distribution is symmetric, ______ and ____________ are common to report.
- For continuous data whose distribution is skewed, _______ and ____________ are common to report.
- histogram
- mean and SD
- median and IQR
For categorical data, ______ and _______ are common to report to describe it.
-count and percent
To visualize the distribution of continuous data, _____ may also be drawn as well as __________.
- boxplot
- histogram
To visualize the distribution of a categorical data, _______ or ________ may be drawn.
-pie graph or bar graph
____________ research is conducted to provide an in-depth understanding of the study population.
Descriptive
Is descriptive or correlational research for making predictions?
correlational (exploratory and explanatory)
______________ study describes interesting, new and unique cases to build a foundation for clinical science.
Case report
_____________ provide an overall picture of the group’s characteristics using surveys as a source of data to collect information.
Descriptive surveys
___________ research involves the description of developmental change and the sequencing of behaviors in people over time.
Developmental
__________ studies describe typical or standard values for characteristics of a given population.
Normative
____________ research is to explore and understand human behavior that arises from a different philosophy than quantitative research designs.
Qualitative
WEEK 5
WEEK 5
___________ is the method used to find the causes of health outcomes and diseases in populations to identify those who have a specific disorder, when and where the disorder developed and what exposures are associated with its presence.
Epidemiology
____________ epidemiologic studies can be presented as case reports, correlational studies, or survey studies to study the disease frequency by reporting the ____________ or ____________.
- Descriptive
- prevalence (P) or incidence (CI; IR)
Prevalence = ?
Prevalence = number of existing cases of a disease at a given point in time / total population at risk
Cumulative incidence (CI) = ?
number of new cases during given time period / total population at risk
Incidence rate (IR) = ?
number of new cases during given time period / total person-time
____________ epidemiologic studies can be presented as cohort studies or case-control study to estimate the risk of an exposure to the development of a disorder by reporting _____________ for cohort studies or ___________ for case-control studies.
- Exploratory
- relative risk (RR) for cohort studies
- odds ratio (OR) for case-control studies
What is used to determine risk?
2x2 contingency table
____________ research is conducted to investigate the relationship between exposure and disease status.
Exploratory
Exploratory research can be carries out ____________ or ______________. Describe each.
- retrospectively- collects data in present and past
- prospectively- collects data in present and future
What is the difference between cross-sectional study and longitudinal study?
- Cross-sectional- collects data at one point in time
- Longitudinal- collects data in multiple points over time
Which is usually done first, cross-sectional or longitudinal and why?
cross-sectional because it is cheap and easy to gather initial data and identify correlations
- Researcher in a ________ study selects a cohort who do not yet have the outcome of interest and follows them to see if they develop the disorder.
- Researcher in a ____________ study looks backward in time to determine if the case- and the control- groups differ on their exposure histories.
- cohort
- case-control
WEEK 6
WEEK 6
What is the purpose of using inferential statistics?
To make a decision about the population group based on the information of the sample group.
______________ are the differences between the sample values and the population values.
Sampling errors
Sample ______ together with its standard error can picture what the sampling distribution looks like and can provide an interval estimate for the population mean.
mean
__________________ is performed to make a decision about the population by rejecting or retaining the null hypothesis based on the resulting quantity called p-value.
Statistical Hypothesis Testing (SHT)
________ as a result of running a SHT is used to make a decision.
p-value
- Type 1 Error =
- Type 2 Error =
- Type I = reject a true null (false positive)
- Type II = nonrejection of a false null (false negative)
- ______________ for the mean difference is checked for inclusion of its null value of __ for the significant effect.
- _____________ interval for the ratio is checked for inclusion of its null value of 1 for the significant effect.
- CI, 0
- CI, 1
___________ research provides a structure for evaluating the cause-and-effect relationship between a set of independent and dependent variables.
Experimental
In true experimental design, subjects are randomly assigned to at least ____ comparison groups.
2
When a true experimental design is not feasible, ____________ design is useful lacking random assignment or comparison groups, or both.
-quasi experimental
- In ________-subjects design subjects are randomly assigned to independent groups.
- In ________-subjects design subjects act as their own control.
- between-subjects
- within-subjects
By the number of independent variables, design can be _______-factor or ______-factor.
-single-factor or multi-factor
When a pretest-posttest design is either impractical or potentially reactive, ________ only design is useful.
posttest only
______________ design and _________ design are the types of within-subjects design.
Repeated measures design and crossover design
_____ design is available when you have both the within-subjects factors and between-subjects factors.
Mixed
WEEK 7
WEEK 7
_______________ is a proper SHT for testing the mean difference between the two independent groups.
Students t-test
______________ is a proper SHT for testing the mean differences between the two related groups.
Paired t-test
______________ is an extension of a Student’s t-test for multiple groups.
ANOVA
_________________ is an extension of a paired t-test for multiple points in time.
Repeated Measures ANOVA
_________________ is applied when the mean differences were compared by multiple factors.
Factorial ANOVA
_____________ is applied when the mean differences were compared by multiple factors over time.
Mixed ANOVA
_________________ is applied when the mean differences were compared controlling for a confounding variable.
ANCOVA
WEEK 8
WEEK 8
_________ tests are available when data is ____________ and work on the principle of ranking the data.
- non-parametric
- non-parametric
For data to parametric, the data should be ___________ and checked for its _______ distribution and equal variances across the groups to compare.
- continuous
- normal
______________ alternative tests are available when the data violates any assumption to be parametric. Most non-parametric methods are based on the ranking scores procedure.
non-parametric
_____________ test is a non-parametric alternative to Student’s t-test,
Mann-Whitney U
______________ test is a non-parametric alternative to ANOVA.
Kruskal-Wallis H
_________ signed-ranks test is a non-parametric alternative to paired t-test.
Wilcoxon
_________ test is a non-parametric alternative to repeated measures ANOVA.
Friedman
WEEK 9
WEEK 9
__________ test is a proper test for testing the proportion between the two or more independent groups.
Chi-square
What are the assumptions to check before running a chi-square test?
- the 2 factors are independent
- the value of the cell expected count should be 5 or more in 80% of the cells
- no cell should have an expected count of less that 1
_______ test s available when the factors are not independent.
McNemar
____________ test is available when the data is sparse having cell expected count less than 5.
Fishers Exact
For the data presented in a 2x2 contingency table, __________ can be computed for each case of chi-square test and McNemar test.
odds ratio (OR)
WEEK 10
WEEK 10
The association between two variables can be measured using ___________________.
correlation coefficients
__________ correlation coefficient measures the linear correlation between two continuous variables X and Y.
Pearson
____________ correlation coefficient is a non-parametric analog of the Pearson r and also appropriate for use when X and Y are ordinal variables.
Spearman rank
_____________ correlation coefficient is appropriate for use when X is dichotomous and Y is continuous.
Point biserial
_________ coefficient is appropriate for use when both X and Y are dichotomous variables.
Phi
Correlation coefficient value r quantitatively describes the strength and direction of a relationship between ____ variables.
two
The prediction of an outcome from a variable can be tested using _______________.
regression analysis
- Linear regression examines the causal relationship of X to Y when Y is ____________.
- Logistic regression examines the causal relationship of X to Y when Y is ____________.
- continuous
- dichotomous
The __________________ quantitatively describes the percentage of the total variance in the Y scores that can be explained by the X scores.
coefficient of determination (R2)
WEEK 11
WEEK 11
______________ is a collective term for the methods of analysis for survival data as being used to analyze the time to an event data in the presence of censored observations.
Survival Analysis
__________ observations are those who have not yet reached the terminal event by the end of the study so whose information about their survival time is incomplete.
Censored
Standard comparison tests such as analysis of variance or regression methods cannot be used for survival analysis because survival times are typically not __________ distributed and come with the presence of ___________ observations.
- normally
- censored
__________ survival curve is widely used in clinical research to visualize the estimate of the survival over time.
Kaplan-Meier
_________ test is appropriately used to compare two or more independent groups with the time to an event data.
Log-rank
___________ hazard model is appropriately used to compare two or more independent groups for the time to an event data controlling for a confounding variable and it also estimates a HR with its 95% confidence interval.
Cox proportional
WEEK 12
WEEK 12
The application of ______________ involves grouping similar variables into factors.
factor analysis
___________________ is used to explore the possible underlying factor structure of a set of observed variables without imposing a predefined structure of the outcome.
Exploratory Factor Analysis (EFA)
______________________ is used to test the hypothesis that there exists a relationship between the observed variables and their underlying latent constructs.
Confirmatory Factor Analysis (CFA)
What are the steps on an exploratory factor analysis?
- developing factors
- extracting factors
- rotating factors
- naming factors
_________ of factor analysis stem from its subjectivity and judgmental nature in decisions; specifically, factors are not real measurement entities only being hypothetical statistical concepts; the resulting data structure is subject to different selection of extraction or rotation methods; the generated factors may be totally uninterpretable within the framework of the research question.
Limitations
WEEK 13
WEEK 13
The application of cluster analysis involves grouping similar cases into homogenous groups (called clusters) when the grouping is not previously known
With hierarchical clustering, the clustering is mapped into a hierarchy basing its grouping on the inter-cluster similarities or dissimilarities
With k-mean clustering, data is classified into K number of clusters mapping each individual data into the cluster with its nearest mean
With two-step clustering, a sequential approach is first used to pre-cluster the cases, and second the pre-clusters are statistically merged into the desired number of clusters
Two step clustering may be a better choice over hierarchical or k-mean because the two step clustering can work with categorical data and it is not bound to an arbitrary choice of the number of clusters
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