EBP II Exam 1.txt

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1. P-value:
probability of false positives in the study result
2. Null Hypothesis:
will be 0 for the difference in groups; while the null will be 1 for OR, HR, RR
3. Mean:
the average, this will be the middle of the bell shaped curve
4. Median:
the value that divides a series of numbers in half when they are listed in order, this will be used for skewed data that does not conform to the bell shaped curve
5. Mode:
the most frequently occurring number in a series
6. Standard deviation:
found using the patient population, square root of the variance, (the average sum squared difference from the mean); measurement of participant variability, measurement in the variability of data, how spread out it is
7. Interquartile Range:
the interquartile range (IQR), also called the mid-spread or middle fifty, is a measure of statistical dispersion, being equal to the difference between the third and first quartiles. IQR = Q3 − Q1
8. Skewed distribution:
non-normal bell curve
9. Normal distribution:
normal bell curve, symmetric around the mean with the mean as the peak of the curve going out toward but never reaching 0
10. Standard error of the mean:
found with the clinical data, the spread of the sampled means for the data gathered, the measure of the precision/variability of the measurement (SD)
11. Confidence Interval:
“the neighborhood of the truth” An estimated range of values around a point estimate. Example: The 95% confidence interval says there is a 95% chance that the actual value found is within the C.I. Precision of study results, range of values that is likely to contain the population parameter
12. **Type 1 error is considered worse because….?
it would lead to unnecessary treatment of patients**
13. Type I error:
stating there is a difference in groups when there isn’t one , incorrectly rejecting the null hypothesis AKA failure to accept the null, will result in false positives
14. Type II error:
stating that there is no difference in groups where there is one, incorrectly accepting the null hypothesis AKA failure to reject the null, will result in false negatives
15. Power:
the probability to correctly reject the null hypothesis when you should. Mathematically defined as 1-Type II error rate, depends on: sample size, difference between groups and type 1 error
16. Clinical significance:
Is the study result of practical interest? Do other findings matter?
17. Chi-square test:
comparison of categorical data for large sample chosen, may be used to compare groups…test whether observed frequencies are different from expected frequencies in a data table
18. Fisher's exact test:
categorical for small sample chosen (>5 subjects)
19. The t-test:
a statistical test used to detect the difference in two means, two groups, and factor in variability in data commonly used for continuous data, comparison of 2 different groups
20. The paired t-test:
a t-test for used when comparing two means that are within the same group Ex. The mean at the beginning of a study and the mean at the end of the study, comparison of dependent groups
21. Wilcoxon test:
a test for statistical significance of data that is not on a normal bell curve distribution (non-parametric), used for paired data–used for group comparisons, rank testing
22. Mann-Whitney U test:
a test for statistical significance of data that is not on a normal bell curve distribution (non-parametric), used for unpaired data –used for group comparisons, rank testing
23. ANOVA (analysis of variance):
A way to analyze groups of means to see if they are equivalent or not; if the ANOVA model fits the data well, and if a statistically significant difference is detected then post-testing is conducted
24. Post-hoc testing:
• compare the group pairs, done in the second stage of statistical analysis…three types:
• • Tukey-used if the groups are unequal in size
• • Bonferroni-for both equal and unequal groups
• • Scheffé-very conservative to minimize type 1 error
25. Linear regression:
explains the differences in means. A calculation of the line of best fit passing through a set of data, which will allow for prediction about direction and amount variables change
26. Multiple linear regression:
explains the differences in means, in addition to explaining the differences in groups it can also be adjusted for age, gender, smoking, cancer etc…
27. Logistic regression:
allows for comparison of differences in odds between groups, results are an odds ratio which is a slight over estimate of relative risk
28. Multiple logistic regression:
in addition to explaining differences in OR between groups, they also adjust for age, gender, smoking, cancer etc…
29. Parametric tests:
t-test, ANOVA, regression
30. Non-parametric tests:
for ranking: Wilcoxon, Mann-Whitney; for categorical data: Chi-square, Fisher’s exact
31. Temporality:
cause must come before effect
32. Repeatability:
the effects must be repeatable
the does response effect—small dose and small response v. big dose and bigger response
34. Reversibility:
de-challenge v. re-challenge aka the interventional effect
35. Plausibility:
Does what’s happening makes sense according to biological knowledge at the time
36. Systemic error:
bias
37. Random error:
chance
38. Numbers Needed to Treat (NNT):
the number of patients who would need to be treated in order to prevent one additional bad outcome
39. Numbers Needed to Harm (NNH):
the number of patients who would need to be treated in order for one bad outcome to occur
40. Absolute Risk (AR):
• •Mainly used with RCT
• •Probability of disease in the exposed group minus the probability of disease in the unexposed group
• •Represents the excess risk due to exposure to the factor under investigation
41. Interpretation of Relative Risks (RR), their confidence intervals, and the type of study that reports them:
• • RR is used to assess the influence of treatment/prevention strategies of potential hazards upon the prevalence of a given condition in a given population
• • RR will typically be used in cohort studies
• • RR is the probability of disease in the exposed group divided by the probability of disease in the unexposed group
• • RR >1 there is a positive association with the risk of disease
• • RR<1 there is a negative risk association with the risk of disease
• • RR=1 there is no association with the risk of disease
42. Interpretation of Odds Ratios (OR), their confidence intervals, and the type of study that reports them:
• • OR is used to assess how exposure to something effects disease
• • Used with case control studies
• • OR >1 those who are exposed are more likely to be diseased
• • OR<1 those who are exposed are less likely to be diseased
• • OR=1 there is no association with exposure and disease
• • If 1 is included within the confidence interval then the results are not considered statistically significant
43. Interpretation of Hazard Ratios (HR), their confidence intervals, and the type of study that reports them:
• • An estimation of harm given an exposure to a specific hazard
• • RR is the hazard of disease occurrence in the exposed group divided by the hazard of disease in the unexposed group over time (RR/time)
• • Used to assess the potential hazards of upon the nearness of an event
• • Used in studies looking for longer survivals due to a harmful or beneficial exposure
• • HR >1 there is a positive association
• • HR<1 there is a negative risk association
• • HR=1 there is no association
44. Cross-Sectional Design:
assess health status and exposure level of subjects at a point in time
45. Case Control:
retrospective observational study comparing diseased and non-diseased groups
46. Cohort:
prospective observational study comparing diseased and non-diseased groups
47. RCT:
prospective experimental design where the sample is broken into 2+ groups who are then put into categories such as treatment, placebo, alternative treatment, double dosage etc.
48. What Kind of Study is good for Diagnosis:
Cross-Sectional analytic study
49. What Kind of Study is good for Harm:
Cohort Study, population based case control
50. What Kind of Study is good for Prognosis:
Cohort study
51. What Kind of Study is good for Treatment:
RCT, systematic review
 Author: primo1289 ID: 183320 Card Set: EBP II Exam 1.txt Updated: 2012-11-13 02:41:36 Tags: EBP II Study Guide UWS Folders: Description: EBP II Study Guide Show Answers: