FCM - Research Design 2: Experimental

Observe only

In an observational study, what is the role of the investigator?

False

T/F: In observational studies, the investigator manipulates variables.

Intervention

What distinguishes an experimental study from an observational one?

False

T/F: Experimental studies aim to observe natural outcomes without interference.

RCT

What is the gold standard design for testing interventions?

Test effectiveness and safety

Main purpose of an RCT.

True

T/F: RCTs measure intervention outcomes under ideal conditions.

Intervention and control

Two main comparison groups in an RCT.

Comparison, randomization, blinding

Three core principles of an RCT.

RCT

Study design that controls for confounders and allows causal inference.

Research question

First stage in conducting an RCT.

PICO

Framework used to define an RCT research question.

Enrollment

Second stage of an RCT process.

Inclusion-exclusion

Criteria used to determine eligible participants.

Allocation

Third stage of an RCT process.

Follow-up

Fourth stage of an RCT process.

Analysis

Final stage of an RCT process.

False

T/F: Randomization occurs before enrollment.

Random assignment

Another term for random allocation.

Confounding

Key problem in observational studies that randomization prevents.

Balance groups

Main goal of randomization.

True

T/F: Randomization prevents both known and unknown confounders.

Care method

In an RCT testing labor management, what is randomized?

Equal chance

Each participant has what kind of chance for allocation?

False

T/F: Random assignment depends on researcher preference.

Selection bias

Randomization prevents what type of bias?

Confounders

Randomization balances what between groups?

True

T/F: Randomization ensures groups differ only in intervention.

Individual

Smallest unit that can be randomized.

Generate sequence

First step in randomization.

Coin toss

Historical methods for generating random sequence.

Computer software

Modern method for generating random sequence.

Allocation concealment

Second step in randomization.

Prevent bias

Main purpose of allocation concealment.

False

T/F: Investigators should know the next assignment in sequence.

Sequentially Numbered Opaque Sealed Envelopes

SNOSE stands for what?

SNOSE

Best method for small sample allocation concealment.

Third party

Who performs central randomization?

True

T/F: Proper concealment prevents manipulation of assignments.

Uncertainty principle

Ethical principle allowing randomization when uncertain of best treatment.

Clinical equipoise

Ethical principle allowing randomization when experts disagree.

False

T/F: Randomization is ethical when consensus on best treatment exists.

Reduce bias

Purpose of blinding in RCTs.

Ascertainment bias

Bias prevented by blinding.

Fours

Number of blinding levels possible.

False

T/F: Blinding and allocation concealment are identical.

Superiority trial

Trial type testing if new treatment is better than existing.

Equivalence trial

Trial type testing if new treatment is as good as standard.

Efficacy trial

Trial type testing performance in ideal conditions.

Effectiveness trial

Trial type testing performance in real-world settings.

True

T/F: Efficacy trials maximize internal validity.

True

T/F: Effectiveness trials maximize external validity.

Phase I

First trial phase in humans.

Phase II

Phase that focuses on efficacy and side effects.

Phase III

Phase comparing new vs. standard treatment.

Phase IV

Phase equivalent to post-marketing studies.

False

T/F: Phase I trials involve sick patients.

Open-label

Type of RCT with no blinding.

Single-blind

Type where participants are unaware of assignment.

Double-blind

Classic design where participants and assessors are unaware.

Triple-blind

Type where patient, doctor, and analyst are unaware.

Quadruple-blind

Type where all participants, analysts, and assessors are unaware.

Bias

Systematic deviation of results from the truth.

Selection bias

Bias from improper selection or allocation.

Information bias

Bias from lack of blinding.

False

T/F: Allocation concealment prevents ascertainment bias.

Internal validity

Main strength ensuring accurate causal inference.

Balanced groups

Key strength regarding confounder control.

Expensive

Main limitation of RCTs in terms of practicality.

Placebos

Major limitation involving ethical issues.

Low external validity

Limitation due to strict eligibility criteria.

False

T/F: RCTs are ideal for rare or long-term outcomes.

Quasi-experimental

Type of experimental design without randomization.

Resembling

Prefix “quasi” means what?

True

T/F: Quasi-experiments still involve intervention.

No randomization possible

When are quasi-experiments performed?

Ethical, practical

Two main reasons for using quasi-experiments.

Non-equivalent groups

Quasi-experimental design with two non-random groups.

Pretest-posttest

Quasi-experimental design with one group measured twice.

Interrupted time series

Quasi-experimental design with repeated measures over time.

Combination

Design combining pretest-posttest and non-equivalent groups.

Assignment bias

Bias when groups differ before intervention.

Maturation

Factor causing change between pre- and post-test due to aging.

History

Factor when outside events affect study outcome.

Regression to mean

Phenomenon where extreme scores move toward the average.

True > Quasi > Correlational

Rank internal validity from highest to lowest.