Deck 8: Analytic Epidemiology: Advanced Designs

Question 1

Describe how bias can influence the results of a study.

Answer 1

Bias can occur in several aspects of the study including selection bias and information bias. Bias in a study can alter the results of the study leading to results that are not accurate. Selection bias includes aspects such as participants not responding to surveys, which could cause a group of people with a particular outcome to not be measured. This would prevent the researcher from seeing anything about an outcome. Information bias occurs when researchers cannot adequately collect the needed information. This would result in incorrect or lacking information about an outcome. Either type of bias reduces the accuracy of the data being gathered and results reported.

Question 2

Discuss the importance of blinding to strengthen a study.

Answer 2

Blinding is a process used to reduce outside influence on a study. Blinding can be done in several ways: the participants are not informed whether they are in the control or intervention group, the statistician is not informed of the study details, or data collectors are not informed about the details of the study. Blinding can use a single, double, or triple approach, depending on how much the researcher feels is necessary to prevent outside influence on the study. Blinding of participants, for example, would reduce the likelihood of participants believing they have had some effect from the study when they haven't. Blinding of the data collectors reduces influence to alter participant responses. Blinding of statisticians prevents bias in the evaluation of data. All aspects of blinding are applied to improve the quality of the study results.

Question 3

Discuss how the application of ethics may hinder the ability to determine if an outcome would occur related to an intervention using a randomized controlled trial or randomized community trial.

Answer 3

When adhering to ethical principles of research, it is sometimes not possible to study if an intervention would lead to an outcome. This occurs when it is generally known or suspected that the intervention would cause harm to the participants or the withholding of an intervention would likely cause harm. Applying ethics would also potentially prevent a study from being completed. For example, if it becomes apparent during a study that the intervention (either applied or withheld) leads to harm or detriment to the participants, the study would be suspended. Because of the application of ethics, it isn't always possible to directly study the impact of an intervention. This doesn't mean the intervention cannot be studied; rather, it means that other study designs may be needed to ethically study the phenomena.

Question 4

Which example demonstrates a causal association between a variable and an outcome?

A) Vegetarians experience anemia.
B) Genetics are involved with sickle cell disease.
C) Obese adults develop Type 2 diabetes mellitus.
D) Sleep disorders are prevalent among children.

Question 5

The nurse becomes aware of an increase of septicemia among adolescents and young adults in a community, which appears to be associated with intravenous drug abuse. When initiating a study of the issue, which type of information bias is the nurse most likely to observe?

A) Recall bias
B) Reporting bias
C) Surrogate bias
D) Surveillance bias

Question 6

A study is initiated in which the benefits of fluoride in toothpaste are to be evaluated. The population for the study includes children in public elementary school who get dental checkups every six months. Which type of trial is used for this study?

A) Randomized Assignment Trial
B) Randomized Community Trial
C) Randomized Selection Trial
D) Randomized Inclusion Trial

Question 7

The nurse is preparing to initiate a study about the differences in growth rates of children within a specific community. Which factor of the study is likely to be a point of concern for the Institutional Review Board (IRB)?

A) Consent forms are written at a fifth grade reading level.
B) Access to the medical records of participants is required.
C) Transportation and a stipend is provided for participants.
D) Participants can withdraw from the study at any time.

Question 8

The nurse submits a proposed research project to the IRB of an acute healthcare facility. The study will focus on the incidence of hospital-acquired infections in post-surgical patients. The IRB turns down the nurse's proposal. Which reason is most likely to have impacted the IRB's decision?

A) Political motives
B) Complexity
C) Confidentiality
D) Useful outcomes

Question 9

A direct causal association implies there is some sort of intermediate step between the variable X and the outcome Y.

Question 10

Confounding is a distortion of an association between an exposure and outcome because of the influence of the third variable that was not considered in the study design or analysis.

Question 11

Quasi-experimental designs require the inclusion of a control group.

Question 12

Reviewing causality criteria and deciding if there is enough support to propose causality is a _______ process.

Question 13

The term intervention ________ is used to describe the degree to which an intervention was delivered as intended.