Factors Influencing Group Assignment in Clinical Trials

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Why is it important to consider factors like illness severity and age when assigning groups in a study?

To reduce bias in the study (correct)
To increase the number of participants in the study
To ensure faster completion of the study
To complicate the study design

What is the benefit of using homogenous groups in a study?

Reduce the number of participants required
Increase the likelihood of detecting an effect (correct)
Cause bias in the study results
Slow down the study process

In a trial, what is an essential characteristic of the intervention being compared?

Having unpredictable outcomes
Being compared to a placebo or gold standard (correct)
Being completely different from the control
Not having a beginning or endpoint

What should outcome measures in a study ideally be?

Clinically relevant, easily measured, and accurately measured (A) Signup and view all the answers

What is a common problem encountered when measuring study outcomes?

Losing patients due to various reasons (A) Signup and view all the answers

Why should losses in study participants ideally be similar for both the intervention and control groups?

To avoid bias in the study results (B) Signup and view all the answers

What is a rule of thumb regarding the proportion of lost study participants in a trial?

Less than 20% (A) Signup and view all the answers

What is the goal of Phase III of clinical trials?

To test rigorously usually with randomised controlled trials (B) Signup and view all the answers

Which term describes how well a diagnostic test is positive in individuals who have the disease?

Sensitivity (A) Signup and view all the answers

What is the focus of Phase IV of clinical trials?

To perform post marketing surveillance (A) Signup and view all the answers

Which term describes how reliable a test result is when it indicates that a disease is present?

Positive predictive value (B) Signup and view all the answers

What does specificity measure in a diagnostic test?

How well the test is negative in individuals without the disease (A) Signup and view all the answers

During which phase of a clinical trial is random assignment most commonly used?

Phase III (B) Signup and view all the answers

What is the primary focus of Phase I of clinical trials?

Assess dosage and safety (C) Signup and view all the answers

In clinical trials, what does Phase II primarily aim to evaluate?

Initial clinical assessment (B) Signup and view all the answers

Which metric indicates the reliability of a test result when it shows that a disease is not present?

Negative predictive value (D) Signup and view all the answers

What is the primary purpose of critical appraisals in systematic reviews?

To evaluate the methodology and external validity of the studies (C) Signup and view all the answers

In a randomized controlled trial, what is the primary reason for randomization?

To minimize bias in the assignment of participants to treatment groups (B) Signup and view all the answers

What is the main difference between a cohort study and a case-control study?

Cohort studies look at exposures and then outcomes, while case-control studies look at outcomes and then exposures (B) Signup and view all the answers

In a well-designed study, what is the primary purpose of inclusion and exclusion criteria?

To define the target population and ensure the sample is homogeneous (D) Signup and view all the answers

What is the key characteristic of a systematic review?

It uses systematic and explicit methods to identify and appraise relevant research (C) Signup and view all the answers

What is the primary advantage of using homogeneous groups in a study?

It reduces confounding variables and increases precision (A) Signup and view all the answers

What is the main purpose of comparison groups in a study?

To compare the outcomes of different interventions or exposures (B) Signup and view all the answers

What is the primary purpose of blinding in a clinical study?

To eliminate bias in the outcome assessment (D) Signup and view all the answers

Which of the following outcome measures indicates the proportion of individuals who need to be treated in order to prevent one additional adverse outcome?

Number needed to treat (NNT) (B) Signup and view all the answers

Why is it important to have homogeneous groups in a study?

To minimize the effect of confounding variables (C) Signup and view all the answers

Which research method involves observing people without directly interacting with them?

Non participant observation (C) Signup and view all the answers

What is a 'confounder' in a study?

A variable that affects both the treatment and the outcome (D) Signup and view all the answers

What is the main advantage of using randomization in a study?

To ensure the treatment and control groups are as similar as possible (C) Signup and view all the answers

What is the primary goal of an iterative approach in research?

To alter methods as the study progresses (B) Signup and view all the answers

What is the primary purpose of randomization in a randomized controlled trial?

To reduce bias by preventing differences between groups from affecting the outcome (C) Signup and view all the answers

Which type of study design involves following research participants over a period of time?

Cohort study (D) Signup and view all the answers

What is a characteristic of a cross-sectional study?

Measuring the outcome and exposures in the study participants at the same time (B) Signup and view all the answers

What is the primary difference between the two groups in a case-control study?

One group has the condition being studied, and the other group does not (C) Signup and view all the answers

What is the purpose of having homogeneous groups in a study?

To reduce bias and ensure comparability between groups (B) Signup and view all the answers

What is a key feature of a randomized controlled trial in terms of intervention comparison?

The population receiving the intervention and the population being compared are only different because of random variation (A) Signup and view all the answers

What is the purpose of an intervention in a study?

To compare the effect of the intervention to a control group (A) Signup and view all the answers