LEVELS OF EVIDENCES Flashcards
Nursing research is designed to yield important
knowledge about phenomena of interest to
nurses and their clients. Knowledge of relevance
to nurses has many roots.
Thinking about the facts you have learned
relating to the practice of nursing, do you know
the source of this information? Some facts are
derived from research; some are not. Clinical
knowledge used in nursing practice is derived
from many sources.
Sources of Knowledge
Within nursing profession, certain beliefs are
accepted as truths (and certain practices are
accepted as effective) simply based on customs.
For example, one of the tasks traditionally
performed by nurses is the change-of-shift report
for each and every patient, whether or not the
patient’s condition has changed, without proving
its productivity and/or effectiveness under
certain circumstances. But traditions may
undermine effective problem solving.
Tradition
An authority is a person with specialized expertise
and recognition for that expertise.
✓ Dependency on nursing authorities (such as
nursing faculty) is inevitable.
✓ Authorities as a source of information have
limitations as:
- May depend on their personal experiences.
- Their knowledge often goes unchallenged
Authorities
We all solve problems based on observations and
experiences.
✓ Personal experiences are based on recognition,
generalization, and predictions based on
observations.
✓ Personal experience has limitations as:
- Each person’s experience may be too
restricted to be useful.
- Personal experiences are often biased.
Personal Experience
(Clinical Experience)
approach to nursing knowledge usually involves multiple attempts
to solve a particular problem until a satisfactory solution is found.
Trial and Error
Limitation of this method: Trial And Error
✓ This method of knowing is inefficient because:
- A number of attempts are usually required before a solution is found.
- It could be hazardous to client safety.
- The solution found may be specific to a particular client and setting and
not generalizable to a broad population.
knowing is “the ability to understand a situation
or phenomena as a whole without reasoning or previous
study”.
✓ It causes a nurse to respond appropriately in unfamiliar
situations (as a personal experience).
✓ However, controversy exists regarding its validity because
it does not conform to the recent requirements for
evidence-based practice in health care (that is, intuitive
knowing is not predictable, measurable, and
generalizable).
Intuition
“is the mental
processing of ideas to solve
problems”.
✓ Two intellectual mechanisms are
used in reasoning: deductive
reasoning and inductive reasoning.
Logical Reasoning
“The process of developing specific predictions from general principles”.
✓ In this method, a nurse reaches a conclusion by moving from the general to the
specific.
✓ It’s the approach used to test:
predictions & validate existing relationships.
✓ For example:
An obstetrics nurse has noticed over many years of practice that women who have no
support person with them while giving birth require more supportive nursing care than
those accompanied by a mother, a partner, or friend. When this nurse then admits a
young woman in labor who arrives at the hospital alone, the nurse anticipates that
additional care measures will be appropriate for this client.
Logical Reasoning
(Deductive Reasoning)
“The process of developing conclusions and generalizations from specific
observations”.
✓ It moves from the specific to the general.
✓ Specific situations are observed and then combined into a larger, more general
statement that can be tested through research.
✓ For example:
The obstetrics nurse described observed hundreds of individual clients in labor over
many years. From these observations, the nurse was able to propose a general theory
about women who are in labor that could then be tested through formal research.
Logical Reasoning
(Inductive Reasoning)
✓ In making clinical decisions, health care professionals also rely on information that has been assembled for a
variety of purposes.
✓ For example, local, national, and international bench-marking data provide information on such issues as the
rates of using various procedures (e.g., rates of Cesarean deliveries) or rates of infection (e.g., nosocomial
pneumonia rates), and can serve as a guide in evaluating clinical practices.
✓ Cost data that is, information on the costs associated with certain procedures, policies, or practices are
sometimes used as a factor in clinical decision making.
✓ Quality improvement and risk data, such as medication error reports and evidence on the incidence and
prevalence of skin breakdown, can be used to assess practices and determine the need for practice changes.
✓ Such sources, although offering some information that can be used in practice, provide no mechanism for
determining whether improvements in patient outcomes result from their use.
Assembled Information
✓ Research conducted within a disciplined
format is the most sophisticated method
of acquiring knowledge.
✓ Nursing research creates systems of
problem solving that tend to be more
reliable than other sources of
knowledge.
Disciplined Research
✓ When searching for evidence-based information, one should select the highest
level of evidence possible - systematic reviews or meta-analysis.
✓ Systematic reviews, meta-analysis, and critically-appraised topics or articles have
all gone through an evaluation process: they have been “filtered”. Information
that has not been critically appraised is considered “unfiltered”.
✓ As you move up the pyramid, however, fewer studies are available. It’s important
to recognize that high levels of evidence may not exist for your clinical question.
If this is the case, you’ll need to move down the pyramid if your quest for
resources at the top of the pyramid is unsuccessful.
Levels of Evidences
Authors of critically-appraised
topics evaluate and synthesize
multiple research studies.
Critically Appraised Topic
A systematic review that
uses quantitative methods
to summarize the results.
Meta-Analysis
An article in which the authors
have systematically searched for,
appraised, and summarized all of
the medical literature for a
specific topic.
Systematic Review
Authors of critically-appraised
individual articles evaluate and
synopsize individual research
studies.
Critically Appraised Articles
This include a randomized
group of patients in an
experimental group and a
control group. These groups
are followed up for the
variables/outcomes of
interest.
Randomized
Controlled Trials (RCT’s)
Identifies two groups
(cohorts) of patients, one
which did receive the exposure
of interest, and one which did
not, and following these
cohorts forward for the
outcome of interest.
Cohort Study
✓ Involves identifying patients
who have the outcome of
interest (cases) and control
patients without the same
outcome, and looking to see if
they had the exposure of
interest.
Case-Control Study
Is a research design that
track patients with a known
exposure given similar
treatment or examines their
medical records for exposure
and outcome.
Case Series/ Case Reports
Information begins at the bottom
of the pyramid: this is where ideas
and laboratory research takes
place.
✓ Ideas turn into therapies and
diagnostic tools, which then are
tested with lab models and
animals.
Animal Research /
Lab Studies
Handbooks, encyclopaedias, and textbooks
often provide a good foundation or
introduction and often include generalized
information about a condition.
✓ While background information presents a
convenient summary, often it takes about
three years for this type of literature to be
published.
Background Information /
Expert Opinion
