Even More Biases
Blinding
Study Designs
Levels of Evidence
Good Clinical Practice
200

This occurs when the study conclusions represent the truth for the individuals studied because results were likely not affected by bias or confounding.

What is internal validity?

200

In this type of clinical trial, all parties are aware of the treatment the participant receives.

What is an unblinded trial?

200

These types of studies minimizes recall bias.

What are prospective studies?

200

This type of study design is at the top of the EBM hierarchy and statistically combines the results of smaller studies.

What is meta-analysis?

200

This body has the authority to require modifications to research protocols, including protocols of previously approved research.

What is the Institutional Review Board?

400

This occurs when the study conclusions represent the truth for the population to which the results will be applied because both the study population and the reader’s population are similar enough in important characteristics.

What is external validity?

400

This group of individuals is not aware of the treatment that the patient receives in a single-blind study.

Who are the participants?

400

These types of studies are best used for rare conditions, in which there are relatively few individuals that may be encountered in a study site.

What are retrospective studies?

400

Besides meta-analyses, this type of study design may be particularly impacted by publication bias, in which negative or null results are either not submitted for publication or not accepted for publication.

What are systematic reviews?

400
This is achieved when risks to research participants are minimized.

What is beneficence?

600

This type of bias occurs when you do not take into account the effect of one or more variables that are related to both the cause being studied and the outcome.

What is confounding?

600

In this level of blinding, the statistician/data analyst is not aware of the treatment receives until after the analysis is completed.

What is triple blinding?

600

In this study design, groups of individuals who are initially free of disease are classified according to exposure or non-exposure to a risk factor and followed over time to determine the incidence of an outcome of interest.

What are cohort studies?

600

This type of study design is at the bottom of the evidence-hierarchy and reports on unique presentations or outcomes.

What is a case report?

600

This is achieved when the selection of research participants is equitable.

What is justice?

800

This category of study designs are inherently more susceptible to biases.

What are observational studies?

800

This form of bias is also called confirmation bias; It is the tendency of humans to accept information that supports preconceived opinions while rejecting or trivializing information that does not support preconceived opinions or that they do not understand.

What is reader bias?

800

In this study design, individuals with and without a disease of interest are identified; the research team then look back to find differences in exposure to risk factors that may have led to the disease.

What is a case-control study?

800

These types of questions are best answered with prospective, blind comparisons to a gold standard.

What are diagnosis questions?

800

At a minimum, these must be minimized and reasonable in relationship to anticipated benefits in order for an IRB to approve a research protocol.

What are risks?

1000

This type of study design is highly susceptible to this form of bias, in which opportunities for biases are different between study groups.

What are case-control studies?

1000

This term refers to keeping all things between groups similar except for the treatment of interest.

What is symmetry?

1000

In this study design, the presence or absence of a disease or other health-related variable is determined for each participant at one particular time.

What is a cross-sectional study?

1000

This category of evidence includes evidence-based clinical practice guidelines, meta-analyses, and systematic reviews; they do not report on newly conducted experiments.

What is filtered information?

1000

When some or all of a study's participants are likely to be drawn from one of these, the IRB must heighten the monitoring of the informed consent process.

What is a vulnerable population?