Research and Statistical Terminology:

A Clinical Approach

As therapists, you will need to be able to access the large database of research related to occupational therapy practice.

The following charts will review the process and terminology behind using research in your occupational therapy practice.

Evidence-Based Practice

Definition: The meticulous use of current, research-based evidence when making decisions regarding patient care.

Why evidence-based practice is important:
A. Therapeutic practices that are based on the results of current, quality research, provide validity to treatment and to the profession in general.
B. Evidence-based practice is easier to justify to patients, physicians, and insurance companies.
C. Therapists who use evidence-based practice will further their knowledge and skills in occupational therapy, allowing them to provide higher quality treatment to their clients.

Basic steps for using research in practice:
A. Formulate a question regarding the intervention you want to use.
B. Review the best evidence available in the literature
i. Most current publications
ii. Best research design
C. Determine the validity, reliability and clinical application of each research study
D. Determine the usefulness and support of information as it pertains to your question and clinical practice.
E. Base your treatment approaches on the evidence that meets your criteria for research topic, design, and quality.

Patient Intervention Comparison Outcome (PICO)

PICO: A mnemonic to help formulate a clinical question and a search strategy by identifying key concepts.
PICO allows you to develop focused relevant questions. The Centre for Evidence Based Medicine states that “one of the fundamental skills required for practicing EBM is the asking of well-built clinical questions. To benefit patients and clinicians, such questions need to be both directly relevant to patients’ problems and phrased in ways that direct your search to relevant and precise answers”. 

Characteristics of PICO Questions include:
1. Structures and guides the search for literature evidence
2. Promotes a relevant, direct, and clear search
3. Answers- what do I want to know about?
4. Focuses the question by identifying the components in the question
5. Defines the concepts that will be used when performing a complex literature search
6. Promotes access to professional evidence that is relevant to the question
7. Determines if the identified evidence is able to effectively address the question
8. Focuses on elements to support and update clinical practice
9. Provides the information needed to make a decision whether or not the intervention in the PICO question should be implemented

PICO– a question formula that allows you to define your research question and determine the key components of your research.

P: Population / Patient
Who or What? Patient, Population, Problem.
How would you describe a group of patients similar to your group?
What are the most important characteristics of the patient? Primary problem; disease; co-existing conditions.
Consider sex, age and/or race of a patient as this may be relevant to the diagnosis or treatment of a disease.

I: Intervention / Indicator
How: Intervention, prognostic factor or exposure – Drug, procedure, diagnostic test, exposure.
Which main intervention, prognostic factor, exposure are you considering?
What do you want to do for the patient? Prescribe a drug? Order a test? Order surgery?
What factor might influence the prognosis of the patient? Age; co-existing problems.
What exposure has the patient experienced? Asbestos; cigarette smoke.

C: Comparator / Control
What is the main alternative? Comparison or intervention?
What is the main alternative to compare with the intervention?
Are you trying to decide between? Two drugs; a drug and no medication or placebo; two diagnostic tests.
Your clinical question may not always need a specific comparison.

O: Outcome
What are you trying to accomplish, measure, improve, effect, achieve?
What can you hope to accomplish measure, improve or affect?
What are you trying to do for the patient? Relieve or eliminate the symptoms; reduce the number of adverse events; improve function or test scores.
Always evaluate the outcomes in regard to the current issue and to future situations.

It is important to note that not all questions have the “C” component. Perhaps you are not comparing the intervention you are interested in with another intervention. For example in the above PICO, perhaps there isn’t a comparison with NDT patterns and you are inquiring about the effectiveness of constraint induced movement therapy only. Your question would be considered a PIO question.

Examples of PICO

1. You have a patient who has difficulty exercising due to COPD and you wonder if pursed lip breathing techniques may improve their endurance.

P = patients with COPD
I = pursed lip breathing
C = regular breathing
O = improved exercise endurance

“In patients with COPD, does using pursed lip breathing, as compared to regular breathing, improve exercise endurance?”

2. You are working with a recent stroke patient who is having balance issues and you are considering using virtual reality in their therapy.

P = recent stroke, balance issues
I = virtual reality
C = no virtual reality
O = improved balance

“In recent stroke patients, how does using virtual reality affect or improve balance?”

Needs Assessment
A Needs Assessment is the systematic collection, assembly, analysis and dissemination of information on the health of a community. There are a number of different ways that the needs assessment can be conducted. No matter the method that is used, the results should be the same. Most often, a combination of techniques will be used.
An important first step in developing any program is to conduct a thorough needs assessment of the intended community setting in order to evaluate the need for such a program as well as the specific individualized needs of the target population.

Typically, there are a number of questions that guide the assessment. The following questions should be answered:
• Who is requesting the change?
• What is the change that is being asked for?
• When does the change need to be implemented?

3 components of the needs assessment process include:
I. Profiling the Population and Community
II. Data Collection
III. Data Analysis/Interpretation

A needs assessment process involves:
• Collecting the relevant data
• Analyzing the data and synthesizing it
• Strength Weaknesses Opportunities Threats (SWOT) analysis
• Determining the priorities
• Evaluating and identifying alternative solutions
• Creating a plan of action

Data gathering methods in a needs assessment can consist of the following:
• Individual interviews
• Questionnaires and surveys
• Focus Groups
• Independent research
• Observation.

Information to be considered in the collection of data includes:
• Facts about the potential clients and existing services in the area
• The demographics of the population being targeted (including statistics)
• The percentage of individuals over the age of 65 in the area

Types of Research and Hierarchy of Evidence
Different types of research are considered to be higher quality than others. Those that are considered to be the best are placed at the top of what is called the “hierarchy of evidence”. This chart will list the different types of research according to a general hierarchy of evidence, with the best types of research studies listed first. When conducting your own research, you will need to compile your own hierarchy of evidence based on the topic that you are researching.

There are two types of research outcomes:
1. Quantitative – objective measurements and statistical analysis are used in the research design
2. Qualitative – exploratory research to help gain an understanding of a problem or develop a hypothesis for a quantitative research study.
Quantitative research usually falls higher in the hierarchy of evidence than qualitative research.

More detail about quantitative and qualitative research will be provided in subsequent charts.

Important Terms to Remember when Reviewing Research

A research study compares variables against each other to determine their effects on each other.

Basic terms that you will need to know when studying research:

.

Psychometric Properties of Assessments

The psychometric properties of a test or assessment tool used in research include the reliability and validity of the tool.

The following chart defines psychometric properties that you will encounter when reading research.

Qualitative Research

Qualitative research is a form of research that studies people, either individually or by groups, in different contexts. It is systematic but subjective. Observations are unstructured and settings are natural, so descriptions of observations are very detailed. The results of qualitative research keep changing, depending on the contexts observed.

Quantitative Research

Quantitative research is research that uses two groups to compare the effects of a random variable. This type of research is structured so that an experimental group receives the experimental variable and the control group does not receive the experimental variable. The cause and effect relationship between the independent and dependent variables is examined and observations are structured or formal.

-In occupational therapy research, quantitative research uses random selection to assign patients into an experimental group that receives the treatment being studied, and a control group that receives no treatment.

Methodology

Methodology includes how the sampling method for the study is determined.

Here are some terms related to sampling methods:

Z score – desired confidence level. Typical z-scores in research are as follows:

99% – z score =2.576

95% – z score = 1.96

90% – z score = 1.645

Confidence interval – a variable calculated by researchers to estimate how much of the sample falls within the parameters of the actual population scrutinized by the study. It is also called margin of error.

Sample Size: The ideal sample size for a study can be calculated using the following formula:

(z-score)2*SD*(1-SD)/(margin of error)2

Here is an example using a confidence level of 95%, a standard deviation of .5, and a margin of error of +/- 2%.

((1.96)2 x.5(.5))/(.02)2

(3.8416 x .25)/.00004

.9604/.00004

24,010 subjects needed

The smaller the margin of error, the larger the sample size needed. The same study using a margin of error of +/- 5% would only require 385 subjects.

The following chart will review sample methods.

The following charts will review methods of statistical measurement, analysis, and interpretation of results.

Levels of Measurement

Correlation Coefficient
The correlation coefficient measures the linear relationship between two variables.

Pearson’s r value:
– Measures the strength and direction of the linear relationship between two variables.
– The two variables studied are labeled x and y.
– Calculated by dividing the covariance of the sample variables by the product of the standard deviations of the sample variables.
– The r value ranges from -1 to +1. The + and – sings indicate a positive or negative linear correlation.

Analysis and Interpretation of Data Using Descriptive Statistics

This section defines terms used when describing the results of data analysis through statistical methods.

Terms used to measure central tendencies:
–Mean: the mathematical average of all scores.
–Median: the midpoint of all scores. 50% of scores are higher than the median and 50% of scores are lower.
–Mode: the most frequently occurring score in the data set.

Terms used to measure variability and to determine the spread in a data set:
–Range: the difference between the highest score and the lowest score in the data set.
–Standard Deviation: the difference in a score from the mean of the data set. The measure determines the variability of   scores in a data set.
–Normal Distribution: a symmetrical bell-shaped curve that shows the distribution of the scores in a data set.