Translating Evidence Into Practice Flashcards
Describe Biologic Plausibility
- Suggests that something makes practical sense based on knowledge of anatomy, biomechanics and physiology, and provides a logical pathway from basic science to clinical application
- Used when a treatment has yet to be proven by research
What are Basic Research and Applied Research?
- Basic Research - Bench - mostly on animals and in controlled lab setting, limited clinical applicability beyond biologic plausibility
- Applied - Done on clinical populations, directly applies to clinical practice
What are the three basic types of research design?
- Analytical
- Descriptive
- Experimental
Describe Analytical Research
- Attempts to explain phenomena and analyze existing data, including systematic reviews
Describe Descriptive Research
- Describe an observation or relationship
- Include surveys, correlations and epidemiological
studies - Human performance investigations such as biomechanical analysis and EMG are also considered descriptive
Describe Experimental Research
- Follows the scientific method to demonstrate a change in a dependent variable
What are the three sub types of experimental design?
- Pre-experimental: Pre-post-testing of one or more
groups - True experimental: Randomized groups with pre and post-testing, often including a control group
- Quasi-experimental: Designed to fit real-world applications while controlling threats to internal validity by using a pseudo control group
Describe the Levels of Evidence (1-5)
- 1: High-quality, randomized clinical trial (RCT), prospective or diagnostic study Systematic reviews with homogeneity of RCT
- Lesser-quality RCT, retrospective study, cohort, or untreated control RCT Systematic reviews of cohort studies
- Case-controlled studies or systematic reviews of case-controlled studies
- Case series
- Expert opinion
What are the four research databases that provide the most comprehensive search of RCTs for Physical Therapy.?
- Central
- PEDro
- PubMed
- EMBASE
What are the two basic types of statistics?
- Descriptive
- Experimental
Describe Descriptive Statistics
- Identify central tendency (mean, mode, median), variability, and confidence intervals
- Also include correlation between two variables
without noting cause-and-effect
-Include Regression Analysis
Describe Experimental Statistics
- Used for experimental designs and are based on probability within a normal distribution
- Identify cause-and-effect while maximizing ‘true’ variance and minimizing error variance
- Sometimes referred to as inferential statistics
Which Guidelines are used for different types of research designs?
- Consort - RCT
- Strobe - observational studies (descriptive research), including cohort, case control and cross-sectional research
- Stard - Diagnostic Studies
- Prisma - SR and meta analysis
What is Internal Validity?
- The ability of a study to correctly measure and identify differences
- Exists when changes in the dependent variable are due to changes in the independent variable
- Indicates good control of the research design
What is External Validity?
- Ability to generalize the results of a study to a given population
What are confounding variables?
- Anything that may have an effect on the dependent variable outside of the independent variables
What is Observation Bias?
- Refers to examiners potentially rating variables more or less favorably with knowledge of the subject’s grouping
What is Selection Bias?
- Refers to the use of improper subjects for the study, who are usually not representative of the population being studied
- Threat to external validity
What are questions to ask when examining a study for external validity?
- Are the patients described in detail so one can
decide whether they are comparable to those seen
in practice? - Are the treatments or assessments described well
enough so one can provide the same to patients? - Was the clinical outcome relevant and clinically
significant?
What is Type 1 error?
- Overcalling it
- Occurs when there really weren’t differences even though they were found in the analysis (false positive)
What is Type 2 error?
- Undercalling it
- Occurs when there were differences but they were not found in the analysis (false negative)
How are Type 1 and Type 2 Error controlled?
- Type 1: Significance value (alpha)
- Type 2: Statistical Power
What is a p value?
- Probability that the difference between groups is due to random chance
What is Effect Size?
- Standardized value of the relationship between two variables, and provides the magnitude and direction of a treatment effect
- Determined by the difference between the variable means divided by the standard deviation [DM/SD]
- Cohens D is common name
How are Effect Sizes (Cohens D) Interpreted?
- 0.2 - small
- 0.5 - moderate
- 0.8 - large effect size
- sample size is related to the effect size; lower effect sizes require higher sample sizes to detect meaningful differences
What does the World Health Organization’s International Classification of Functioning, Disability, and Health (ICF) do?
- Captures how people with a health condition function in their daily life rather than focusing on their diagnosis or the presence or absence of disease
What is Minimally Cliniical Important Difference (MCID)?
- Smallest improvement considered worthwhile by the patient
What is the interpretation of 95% confidence interval?
- Repeating the study would result in a value
within that range 95 percent of the time
What is the Absolute Mean Difference?
- Measures the difference in means between the treatment and control groups without standardization
What is an Odds Ratio?
- Gives the probability or odds of an event happening or not
- Used in case-control and epidemiological studies, and are determined by dividing the incidence in one group by another comparison group
What is Relative Risk?
- Determined by dividing the proportion of the outcome or incidence of the treatment group by the incidence in the control group
- A value of 0 means there was no effect
- Relative risk of <1 indicates a reduced risk or effectiveness of the intervention
- Relative risk of >1 indicates no effect or increased risk.
What is the Absolute Risk Reduction (ARR)?
- Decrease in risk following treatment in relation to a control
- 20% risk in control and 5% in experimental
- ARR would be 15%
What is Numbers Needed to Treat?
- Average number of patients in a clinical trial who need to be treated for a patient to benefit compared to a control
- NNT is the inverse of absolute risk ratio (NNT = 1/ARR)
What is Prevalence?
- Number of cases that exist within a population at any given time whether diagnosed or not (including those at risk for developing the condition)
What is Incidence?
- Number of newly diagnosed cases during a time period
What is Sensitivity?
- Ability to correctly identify those with the condition
- Values are noted as the percentage of patients who have the problem and test positive
- If a clinical test for an ACL tear is done in 100 patients WITH a tear and the test is positive in 60 patients, it has a 60 percent sensitivity
What is Specificity?
- Ability to correctly identify those without the condition
- Values are noted as percentage of patients who don’t have the problem and test negative
- If a clinical test for an ACL tear is done in 100 patients WITHOUT a tear and the test is was negative in 95, the
test has 95 percent specificity
How is Pearsons R Interpreted?
- ranges from -1 to 1
- If r=1: perfect linear correlation, the increase in one variable is directly dependent on another
- If r=-1: Inverse relationship, increase in one variable is dependent on the decrease of another
- If r=0: no relationship; the variables are independent
What are the “Grades” of Evidence?
- A: Consistent, Level I studies
- B: Consistent Level II or III, or extrapolation of from Level I studies
- C: Level IV studies or extrapolations from Level II or III studies
- D: Level V evidence or troubling, inconsistent, or inconclusive studies of any level
