Evidence-Based Practice for Nurses

True/False

1. In retrospective designs, also known as ex post facto designs, the researcher manipulates
   the IV.


2. Cohort comparison studies can save time because more than one group of subjects is
   studied.


3. The threat of mortality is greater in cross-sectional designs than in longitudinal designs.


4. Any study that involves collecting data at multiple points in time is a longitudinal study.

TEST YOUR KNOWLEDGE 6-3

How did you do? 1. F; 2. T; 3. F; 4. F

6.4 Keeping It Ethical

Researchers are obligated to conduct well-constructed studies. If a study does

not have adequate controls in place, then the researcher has wasted valuable

resources such as time, money, and subject volunteerism. Furthermore, failure

to control threats to study validity jeopardizes the integrity of the findings.

When findings are flawed, patient safety could be affected when practice is

changed based on the evidence. Researchers should make every effort to imple-

ment strategies that enhance control and manipulation while reducing bias.

Implementing strategies needs to be balanced with

protecting the rights of human subjects. For example,

when individuals are recruited for a study that involves

two or more groups, they often express a desire to choose

their group assignment. Allowing subjects to select their

group assignment introduces the threat of selection bias.

Most researchers would opt to randomly assign subjects

FYI

Researchers are obligated to conduct

well-constructed studies. If a study does not

have adequate controls in place, then the re-

searcher has wasted valuable resources such

as time, money, and subject volunteerism.

At the end of this section, you will be able to:

‹ Discuss ethical issues related to internal and external validity

their cost in following subjects over an extended period of time. The threat

of mortality is increased; thus, researchers need to make special plans to

encourage subjects to complete the studies. Maturation is another threat

inherent in longitudinal designs because changes of subjects are inevitable.

Because longitudinal studies involve repeated measurements, the threat of

testing is often increased.

166 CHAPTER 6 Key Principles of Quantitative Designs