Research and Evidence Based Practice Flashcards
What 3 components make up evidence based practice?
Research evidence
Clinical expertise
Patient values
Explain correlation coefficients (r) ranging from -1.00 to +1.00.
R near +1.00 = positively correlated variables
R near 0.00 = variable not related
R near -1.00 = negatively correlated variables
What is a nominal scale? Provide an example.
Classifies variables or scores into two or more mutually exclusive categories based on a common set of characteristics
Example: male or female; tall or short
What is an ordinal scale? Provide an example.
Classifies and ranks variables or scores in terms of the degree to which they possess common characteristics.
Intervals between ranks are NOT equal
Example: MMT
What is an interval scale? Provide an example.
Classifies and ranks variables or scores based on predetermined equal intervals. Does not have a true zero point.
Example: Temperature; IQ scale ranging from 0-200
What is a ratio scale? Provide an example.
Classifies and ranks variables or scores based on intervals and a true zero point.
Example: goniometry, scales for height, weight or force
A _____ scale is the least precise level of measurement, while a _____ scale is the most precise level of measurement.
Nominal = least precise Ratio = most precise
What is the difference between a random versus stratified sample?
Random = all individuals in a population have an equal chance of being chosen for a study
Stratified = individuals are selected from a population from identified subgroups based on some predetermined characteristic (i.e. by height, weight or gender)
What is validity?
Refers to the extent to which a test, instrument or procedure accurately measures what it is supposed to measure
What is the difference between internal and external validity?
Internal = the degree to which the observed differences on the dependent variable are the direct result of manipulation of the independent variable and not some other variable
External validity = the degree to which the results are generalized to individuals or environmental settings outside of the experimental study
What is the Hawthorne effect?
The subject’s knowledge of participation in an experiment influences the results of a study
What is reliability?
The degree to which an instrument measures a phenomenon accurately, dependably, time after time, and without variation
What is the difference between interrater and intrarater reliability?
Interrater = the degree to which two or more dependent raters can obtain the same rating for a given variable
Intrarater = the degree to which one rather can obtain the same rating for a given variable on multiple measurement trials
What is the difference between a subjective versus objective tests?
Subjective = results differ based on who is grading the test
Objective = results will always be the same regardless of who grades the test
What is the difference between sensitivity and specificity?
Sensitivity (SNout) = a test’s ability to correctly identify the proportion of individuals who truly have a disease or condition (true positive)
Specificity (SPin) = a test’s ability to correctly identity the proportions of individuals who do not have a disease or condition (true negative)
What is the purpose of a t-test?
Used to determine if there is a difference between two groups
What is the purpose of an analysis of variance (ANOVA)? How is an ANCOVA different from an ANOVA?
Used to determine whether there are differences among three or more groups.
ANCOVA (analysis of variables) = also controls for the effects of intervening variables as well as assess if there are differences among 3 or more groups
What is the purpose of a chi square test?
Tells the researchers whether the observed pattern, trait or distribution is different than what would have been expected by chance alone
What is the effect size?
Magnitude of difference between groups
What is a p value?
An estimation of true differences, not due to chance
Most commonly set at 0.05 or 0.01
P avalue tells us whether an effect exists, but does not share the size of the effect
Describe the reliability values for positive correlations (r).
Good reliability > 0.75
Moderate reliable = 0.5-0.75
Poor reliability < 0.5
What is a confidence interval?
A range of values so defined that there is a specified (usually 95%) probability that the value of a parameter lies within it
______ are more statistically powerful than sensitivity and specificity.
Likelihood ratios
Very high likelihood ratios (10 or more) rule in a diagnosis.
Ratios or 0.1 or less rule out a diagnosis.
Anything in between is inconclusive.
