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2011-10-12 23:29:18

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  1. What is meta-analysis?
    Combine literature about a topic to arrive at a single summary estimate
  2. Why is meta analysis used?
    • Confirm results
    • Reconcile outcomes
    • Realize and quantify undetected treatment effect
  3. Steps in a meta analysis?
    • Clearly specify all databases
    • Identify all studies on the topic even unpublished data
    • Systematic and transparent process to select studies for inclusion
    • Use structured format to extract outcomes from study
    • Combine the data
    • Have explicit inclusion and exclusion criteria
  4. What are the strengths of the meta analysis?
    • Quality of methods
    • Finding relationships across studies
    • Imposes process of summing up research findings
  5. T/F The quality of the methods is central to the quality of the results?
  6. Limitations of meta anaylsis?
    • Effort
    • If study is comparable based on individual opinion
    • Includes some less than optimal studies
    • Selection and publication bias
  7. When to use a meta analysis?
    • Studies lack substantial power
    • Available results support different conclusions
    • More precise estimate of treatment effect
  8. T/F - Do all hypothesis refer to the population?
  9. What does a parameter describe?
    • Describes the characteristic of a population.
    • Always in GREEK letters
  10. What does a statistic describe?
    • A chracteristic of the sample
    • Always in ROMAN letters
  11. What are the 2 statistical methods?
    • Descriptive
    • Inferential
  12. What is descriptive statistics?
    Collecting, presenting, describing data using formulas, graphs, surveys
  13. What is inferential statistics?
    • Draw conclusions/make decisions about a population based on sample data only
    • Estimation
    • Hypothesis testing
  14. What are the 4 levels of measurement?
    • Nominal - unordered categories no true meaning of value
    • Ordinal - rank ordered categories
    • Interval - no true zero point
    • Ratio - true zero point
  15. What is a cohort study?
    • Follow up
    • Can be prospective or retrospective design
    • Nonrandomized study grps are assigned
    • Observational - researchers only observe
    • Longitudinal - takes a long time to do
  16. What are the 6 advantages of cohort study?
    • Study rare diseases
    • Outcome timeline
    • Avoid recall and survival biases
    • Assess multiple outcomes
    • Measure exposure over time
    • Measure outcome incidence
  17. What are the disadvantages to cohort study?
    • Selection bias
    • Large sample for rare/slow disease
    • Accurate records
    • $$$$$$
    • Loss to follow up
    • Exposure status changes over time
  18. What is prospective cohort study?
    Exposed at beginning of study follow up in the future
  19. What is retrospective cohort study?
    Exposed in the past (historical) outcome assessed as historical records
  20. What are equal measurements?
    • Equal testing and examining in the same way
    • Same diagnostic tests
  21. What are homogeneous grps?
  22. How to calculate relative risk? pg.18
    • Relative risk = (a/a+c)/(b/b+d)
    • >1 = no association
    • <1 = exposed ppl have less risk
    • =1 = equal risk
  23. Strobe criteria?
    checklist of what needs to be included in cohort studies. ex. intro methods...
  24. What is case control?
    • Determine the association between risk factors and outcome of interest
    • Retrospective data collection by choosing subjects in present time already with outcome and checking for risk factors
  25. What are the advantages to case-control studies?
    • $$$
    • Study rare diseases/ long development type things
    • Easy to perform and collect data
    • Hypothesis generation
  26. What are the disadvantages to case control studies?
    • Correlation no causation
    • Bias
    • No time link of outcome and risk
    • Can't calculate outcome incidence
    • Inefficient for rare risk factors
    • Hard to select representatives for cases and controls
  27. What bias occurs in case-control studies?
    • Design bias
    • Recall bias - based off of memory
    • Researcher bias
  28. What is a randomized controll trial?
    • Random assignment of participants into experimental grp and control grp
    • Only difference between the grps is the outcome variable studied
  29. T/F Are all clinical trials interrelated?
  30. What is the format for how information for a trial should be?
    IMRAD - intro, methods, results, and discussion
  31. What are the advantages of parallel trials?
    • Robust for most conditions
    • Randomized
    • Large subjects
    • Fits most experimental situations
  32. What are the disadvantages of parallel trials?
    • Only one treatment
    • Need to match subjects for
  33. What are the 4 types of parallel tests?
    • Simple parallel
    • 3 grp parallel
    • 2 part parallel
    • Multiple dose parallel
  34. What are characteristics of crossover trials compared to parallel trials?
    • Each subject gets all treatments
    • Subject is its own control
    • Less data varability
    • Less subjects
    • More sensitivity
    • Less robust
  35. What are the 3 order effects?
    • Carry-over = drug effect lasts from treatment period to treatment period, reduced with washout period
    • Period = change in pt condition between treatment
    • Sequence
  36. What is an N-of-1 trial?
    • Controlled cross-over study of 1 person comparing their treatment effects to their placebo effects to see if effective
    • Can't apply results to population only to pt
  37. How many phases in a random control trial?
  38. What happens in phase 1?
    • Healthy human volunteers
    • Short duration
    • Assess PK, toxicity, pharm effects
    • Monitor ADR
  39. What happens in phase 2?
    • Safe and effective
    • Have disease condion of interest
  40. What happends in phase 3?
    • Safe and effective
    • Large grp 1000's
    • Months-yrs
    • Have disesase and comorbid conditions
  41. What happens in phase 4?
    • Post market studies
    • Use, effects, and safety in real world conditions
  42. What are cross sectional studies?
    • Observational study
    • Conducted at single or more points in time
    • Simultaneous selecton, assignment, and asessment of subject
  43. What are the 2 types of cross sectional studies?
    • Descriptive - have or no have, point prevalence (1 point in time) or period prevalence
    • Analytical - compare
  44. What are case reports?
    • Describe observations
    • More knowledge of treatment/condition
    • Safer treatment practices
    • Start new research
  45. What are case series?
    • Grp of single cases in one report
    • Subjects have common characteristic
    • Quick and cheap way to report info
    • Shows trends
    • Start new research
    • Report epidemics
    • Evaluate efficacy
  46. What are the limitations of case series?
    • Can't determine causal inferences
    • No control grps
    • No circumstantial evidence
    • Fail to compensate for influences of external forces
  47. What are the 3 types of review articles?
    • Narrative
    • Systematic (qualitative)
    • Meta-analysis (quantitative)
  48. What is a narrative review article?
    • Editorial type - short and narrow focused
    • Commentary type - biased, express a particular opinion
    • Narrative Overview - author's summary of literature (bias)
  49. What is systemic articles better than (narrative articles)?
    • Focused questions (broad)
    • Comprehensive lit search (not specified)
    • Criterion based selection (not specified)
    • Rigorous appraisal (variable)
    • Quantitative (qualitative)
    • EBM inferences (sometimes)
  50. Why is meta analysis good?
    • Combine independent results of trials using statistical analysis to draw conclusions about therapeutic effectiveness or plan new studies
    • Small samples used in original trials
    • Large trial too expensive to perform
    • Solves disagreements on magnitude or direction of effect
  51. List the tests in order that provide the most to least evidence?
    • SR
    • RCT
    • Cohort
    • Case-control
    • Case series
    • Case reports