Transcript Part 1 - Association For The Advancement of Wound Care

I want to test a wound treatment or educational program but I have no funding or resources,
How do I do it?
Implementing & evaluating wound research conducted using pre-experimental designs part I
AAWC WocSpec Research Committee, Barbara M. Bates-Jensen, PhD, RN, Chair
ABSTRACT
PURPOSE: To provide information on how to evaluate and improve
methodology of wound research conducted using pre-experimental designs.
BACKGROUND: Research methodology is concerned with how a study’s
design is implemented and how the research is conducted. Methodology
determines the quality of the data generated by the study and specifies: when
and how often data are collected, construction of data collection measures, who
data is collected from, how data is analyzed, and how findings are presented.
Study design is a part of research methodology but not the only part.
METHODS: Pre-experimental studies include: case study design, static group
comparison or cross sectional design, and one group pre-test/post-test design
including longitudinal time series and panel designs. These designs are
frequently concerned with answering questions using an experimental approach
when resources are not available for conducting more rigorous experimental
designs. We often use pre-experimental designs for description and thus we are
concerned with how to answer questions such as: How many? How much?
How efficient? How effective? How adequate? We present information on
conducting static group comparisons and one group pre-test/post-test designs
for wound research. Advantages and disadvantages and methods for
increasing the strength of pre-experimental wound studies are outlined.
CONCLUSIONS: Pre-experimental designs follow basic experimental steps but
do not include a control group. Usually a single group is studied but no
comparison between an equivalent control group is made. The aim of preexperimental design is to evaluate the influence of a variable or to determine
the influence of a variable on one group and not on another. Limitations of one
group pre-test/post-test designs are that the approach provides a measure of
change but cannot provide conclusive results. Weakness in static group
comparison designs lies in the failure to examine equivalence of groups before
the implementation of the wound treatment or educational program. Methods to
improve the quality of wound research using pre-experimental designs include
attending to: historical events that may have occurred between the pre-test and
post-test, maturation changes in the subjects, difficulties with pencil and paper
measures for pre-tests and post-tests, instrument changes/calibration,
subject/wound selection biases.
BACKGROUND
Research methodology determines the quality of
the data collected in a study, it concerns how the
design is implemented and specifies:
when and how often data are collected
development of data collection measures &
instruments
who data is collected from (the sample)
how data are analyzed
how findings are presented.
Whether or not study results are really the result of
the variable on the group under investigation in the
study (internal validity) and not some other variable
AND
Whether or not the study results can be expected
to be the same with other groups of people
(external validity) are issues that are addressed by
methodology.
Research design is an important part of
methodology. Study design is a part of research
methodology but not the only part.
In general, a research design is the plan for the
research study. The design guides when and how
often to collect data, what data to gather and from
whom, and how to analyze the data.
A research design refers to the type of study that
will be conducted, whether it will be preexperimental, quasi-experimental, or true
experimental.
PRE-EXPERIMENTAL METHODS
Pre-experimental research designs:
 answer questions using an experimental
approach when resources are not available for
conducting more rigorous experimental designs
are used to describe a variable
often answer questions such as: How many?
How much? How efficient? How effective? How
adequate?
follow basic experimental steps but do not include
a control group
usually involve study of a single group with no
comparison between an equivalent control group
The aim of pre-experimental design is to evaluate
the influence of a variable or to determine the
influence of a variable on one group and not on
another.
There are 3 pre-experimental research designs:
1. case study
2. static group comparison/cross sectional
3. one group pre-test/post-test (longitudinal time
series and panel)
Static Group Comparisons or
Cross Sectional Designs
Treatment Group
X
Comparison Group
O1
O1
X = Wound Treatment or Educational Program
O1 = Post observation measurement or Post test
2 groups are chosen; one gets the wound treatment
or education and the other does not. A posttest or
post observation measure is then determined to
measure the difference between the 2 groups. There
is no pre-testing, so any differences between the 2
groups before the study are unknown.
What happens in a static group
comparison/cross-sectional design:
 Data is collected on relevant variables one time only
from a variety of subjects
Data are collected all at the same time
Findings give a “snapshot” of variables in the study at
one particular point in time
Findings reveal how those variables are represented in
a cross section of the population
Uses existing groups, no random selection of
participants, no random assignment to treatment or
comparison groups, SO:
 NO WAY to determine that the comparison and
treatment groups are the same or equivalent at the
beginning and thus, no way to insure that the findings are
related to the wound treatment or educational program
and not some difference that existed at the outset.
Some considerations to improve
Static group comparisons or
Cross sectional studies
EDUCATION:
Measure whether or not the education actually results
in change in behavior. No one cares if a posttest shows
more correct answers, this does not translate into using
the knowledge to improve care delivery.
Present data on the costs associated with the
educational program: time, staff resources to present the
education, technology required., etc.
Present data on attendance at the program (100%
attendance? 75%?)
WOUND TREATMENT:
Use a standardized research based wound
assessment tool which includes a variety of wound
characteristics to assess wound response.
Determine and report reliability of the instruments
used to collect the wound and patient response data.
Include basic demographic information about the
patients and basic information about the wounds.
Include only one wound per patient.
Have someone who doesn’t know about the wound
treatment (blinded) evaluate the wounds.
Select wounds/patients that are similar for both the
treatment and comparison group.
How to make static group
comparison/cross sectional designs
stronger:
Add a Pre-test or Pre-observation measurement
Treatment Group
O1
Comparison Group
O1
X
O2
O2
X = Wound Treatment or Educational Program
O1 = Pre treatment or educational program observation
measurement or Pretest
O2 = Post observation measurement or Posttest
The O1 pretest allows determination of any
differences between the treatment and
comparison group before the wound treatment
or educational program is delivered so any
difference in the posttest or post observation
measurement is more likely to be related to the
wound treatment or educational program.
OR
Randomize subjects to groups
Treatment Group R
X
Comparsion Group R
O1
O1
X = Wound Treatment or Educational Program
O1 = Post observation measurement or Posttest
R = Randomization
Randomizing the subjects in the two groups
allows for interpretation of differences
between the groups on the posttest or post
observation measurement as due to the
wound treatment or educational program.
Limitations
Cannot measure change
Cannot establish cause and effect
Increase chances of error
No control of independent variable
Difficult to rule out rival hypotheses
Static, time limited