Ch. 7 Assessing the Efficiency of Preventative and Therapeutic Measures: Randomized Trials

Question 1

True or False: Randomized Trials are considered the ideal design for evaluating both the effectiveness and the side effects of new forms of interventions.

Answer 1

True

Question 2

What are the potential uses of a Randomized Clinical trial?

Answer 2

Randomized clinical trails can be used to evaluate new drugs and treatments of disease, including tests and medical care technology, assessing new programs for screening and early detection, or even new ways of organizing and delivering health care services.

Question 3

What is the Basic design of a Randomized Clinical Trial/

Answer 3

First, we begin with a defined population that is randomized to receive either new treatments or the current treatment. Next, we then follow the subject in each group to see how many have improved in the new treatment group compared with the current treatment group. In some cases we may choose to use two groups receiving different therapies or we may use more than 2 groups. Although we may choose to use a treatment group compared to a no treatment group.

Question 4

True or False. If the New treatment is Associated with a better outcome, we would expect to find the same outcomes in more of the new treatment groups than the current treatment groups.

Answer 4

False. If the New treatment is Associated with a better outcome, we would expect to find the better outcomes in more of the new treatment groups than the current treatment groups.

Question 5

When the investigator is determining the selection of subjects for a randomized trial what criteria must be met?

Answer 5

There should be no subjective decision making on the part of the investigator in deciding who is and who is not included within the study, therefore the selection criteria for determining who will and who will not be included within the study must be clearly spelled out and stated precisely.

Question 6

What alternatives to randomization can be used ?

Answer 6

1) Studies Without comparison
- Case studies or case series

2) Studies with comparison- Studies that recognize the need to include some kind type of comparison.

• Historical controls
• Simultaneous Nonrandomized controls

Question 7

Define a Case study or Case Series.

Answer 7

Case Study or Case series- Is a when no comparison is made with an untreated group or with a group that is receiving some other form of treatment.

Question 8

Why is the issue of comparison important?

Answer 8

Comparison is important because we want to be able to derive casual inferences regarding the relationship of a treatment and subsequent outcome.

• Results can always be improved by omitting controls.

Question 9

What are Historical controls?

Answer 9

Comparison groups from the past, where we go back to the records of the patient with the same disease who were treated before the new therapy was created.

• Useful if the disease is uniformly fatal and new treatment is available, where environmental factors need to be ruled out.

Question 10

What problems can arise with the use of Historical Controls?

Answer 10

1) we may make-up new very meticulous systems of data collection for new patients and thus are not able to collect such data from the previous patient group. So the observed data may be due to the differences in the quality of data collection.
2) Lifestyle changes overtime can also affect the differences in the results of the drug we are studying or other factors that take place over calendar time.

Question 11

What are the problems associated with the system of Simultaneous Nonrandomized Controls?

Answer 11

1) The assignment system was too predictable and thus was possible to predict the assignment of what the next patient would be.

Question 12

What is Simultaneous Nonrandomized Controls?

Answer 12

The selection of controls based on the odd and even number of days and assigning them to a group.

Question 13

What is one of the primary goals of randomization?

Answer 13

The goal of randomization is to eliminate the possibility that the investigator will know what the assignment of the next patient as it is suppose to be unpredictable and will thus be to eliminate the possibility of selection bias.

Question 14

How do we use a Randomization Table?

Answer 14

First, we begin by assigning either odd and even #’s to a group assignment. Next, we then we close our eyes and place our finger randomly on a column and row anywhere on the table, as ur starting point. Lastly we then choose a direction in which we move in the table being either up, down, left, or right.

Question 15

What is one of the major conflicts faced by the clinician in a randomized trial?

Answer 15

On the one hand the clinican has the obligation to do what they think is best for the patient, but when they decide to participate within a study they are asked to step aside and from their usual decision-making process and essentially flip a coin to decide which kind of therapy the patient will receive. Thus there is an underlying conflict between the clinician’s role and that of the participating physican resulting in an unintentional bias.

Question 16

True or False: If randomization is done correctly we achieve non predictability and thus do not need to worry about subjective bias of the investigators. However, this does not suggest comparability due to chance, but in the long run groups tend to be similar and will be comparable not only in variables that we recognize button those that and are not able to measure for.

Answer 16

True.

Question 17

Define Stratified Randomization.

Answer 17

In this approach we first stratify (layer) our study population by each variable that we consider important and then we randomize participants to treatment groups within each stratum.

Question 18

True or False: It is essential that the data collection is of the the same quality for each of the study groups.

Answer 18

True.

Question 19

True or False: It is ok if we do not know to which group the patient was assigned. Though we must know which therapy the patient actually received.

Answer 19

False. We Have to know both to which group the patient was assigned and which therapy the patient actually received.

Question 20

Why is the need for comparable outcomes particularly true for the measurement of outcomes?

Answer 20

The need for the explicitly stated criteria for all outcomes to be measured in a study to be true, then they must be measured comparably in all study groups to avoid factors that can affect the outcome of the results .

Question 21

True or False: Measurements of outcomes only include those of desired effects.

Answer 21

False. Measurements of outcomes include those of desired effects and any side effects that may appear.

Question 22

True or False: If we know the risk factors for a bad outcome, we want to verify that randomization has provided reasonable similarity between the 2 groups in terms of these risk factors.

Answer 22

True. Though, data should be obtained at the time of entry into study.

Question 23

True or False: It is ok for patients to which group they are in even when using the masking method.

Answer 23

False. The Masking method it is of particular importance that the patient does not know to which group they belong to especially when the outcome is a subjective measure.

Question 24

Define a Placebo.

Answer 24

Placebo- an inert substance that looks like, tastes and smells like the active agent.

Question 25

Why must we be concerned with masking when dealing with subjective measures?

Answer 25

We must be concerned with Masking particularly when dealing with subjective endpoints, and in addition it can important for studying the real benefits and the rates of side effects and reactions when using a placebo.

Question 26

What is double-blinding?

Answer 26

Double-Blinding is the act of masking the observers or data collectors in regards to which group the patients belong to.

Question 27

Why is it important to use the Double-Blining Method?

Answer 27

To shield the study from any potential bias or Preconceptions that may occur either subconsciously or consciously that can interfere with the results of the study.

Question 28

Describe a Planned crossover design.

Answer 28

Subjects are Randomized to new treatment groups or current treatment groups, after being observed for a certain period of time & once the measurements have been properly recorded and allowed a washout period . Then, the patients are switched to the alternative group/therapy and the measurements are recorded again.

Question 29

A planned crossed over Design is very attractive and useful as long as what certain precautions and conditions are taken into account?

Answer 29

1) There must be enough of a washout period allowed to be sure that none of therapy A or its effects remain.
2) The order in which the therapies are conducted may elect a psychological response; thus we want to be sure that any observation observed is due to the agents being evaluated and not to any effect of the order.
3) It is not possible if the new treatment is a surgical procedure or it cures the disease in question.

Question 30

How many types of Crossovers designs are there?

Answer 30

Planned and Unplanned

Question 31

Why does an unplanned crossover occur?

Answer 31

An unplanned crossover may occur. In which the patient elects not to do a procedure or form of treatment A and then is moved into the medical car group or treatment B. Or patients in treatment B or medical care group are deteriorating and thus treatment A may be required.

Question 32

How doe we interpret the data of an unplanned crossover design?

Answer 32

We carryout the intention to that analysis approach. Where we would compare the patients compare according to their original assignments. We hope that this approach will be comparable to the primary approach, and thus have to keep crossovers to a minimum.

Question 33

Describe a Factorial Design.

Answer 33

In a Factorial Design, if the effects of a treatment are indeed completely dependent we could evaluate the effects of a treatment A by comparing the results in cells a+c to the results in cells b+d.

Question 34

What is a possible advantage of the Factorial Design?

Answer 34

In the event that it is decided to terminate the study of treatment A, this design permits continuing the study to determine the effects of treatment B.

Question 35

When does noncompliance occur?

Answer 35

It is when patients may agree to be randomized, but following randomization they do not comply with the assigned treatment. Though the noncompliance may be accomplished overtly or covertly.

Question 36

Describe the difference between Dropouts and Drop-ins .

Answer 36

Dropouts- Overtly articulate their refusal to comply with the treatment or may stop participating in the study.

Drop-ins - Patients who inadvertently take the agent assigned to another group.

Question 37

True or False: It is important that we do not generalize the results of a pre-study that separates the compliers from the non-compliers to the general population, which may be different form the free-living community as it consists of both compliers and non-compliers.

Answer 37

True.

Question 38

True or False: In conducting a study to evaluate a therapy or other intervention, we cannot offer the agent to a population and compare the the effects in those who take the agent to the effects in those who do and those who do not. Due to the fact that they can differ in terms of many demographic, social, psychological, and cultural variables that are important in determining the outcome .

Answer 38

True.