Evidence Based Medicine Flashcards
After a search of the available literature a meta-analysis of acupuncture trials is identified to support the argument in a Chinese medical journal. It included all 256 trials that were published and peer reviewed, Chinese language journals between 1986 and 2006 and included trials of treatment for nausea, backache, migraine… Which of the following statements is true with regards to the interpretation of this paper?
- this paper included a large number of trials and therefore the findings have high validity
- the methodology of this paper is prone to bias
- metaanalysis of this type can be considered the gold standard of evidence based medicine
- the results have been the subject of peer review and so can be assumed to be valid
- this paper has followed the cochrane collaberation guidelines for meta analysis
the methodology of this paper is prone to bias
Qualitative research seeks to analyze the ………….. which researchers collect from people in relation to their ………… and circumstances.
Which of the following suggestions fills in the gaps best?
Select one:
Data, experiences
Data, research
Associations, lives
Experience, meanings
Meanings, experiences
Data, experiences
Which of the following options will help a confidence interval become even more narrow?
Select one:
A smaller sample size
A significantly increased sample size
Studying a population with a lot of variability
Studying a population with more homogeneity
Having a simple study design
A significantly increased sample size
Which of the following statements is true with respect to the idea of a normal (Gaussian) distribution of a population sample.
Select one:
The mode has a higher value than the mean
The median has a smaller value than the mean
The data will be skewed to the right of the mean
The median has the same value as the mean
The mode has a smaller value than the mean
The median has the same value as the mean
Choose the best definition for ‘null hypothesis’ from the following options.
Select one:
The hypothesis that the results of a study are inaccurate
The hypothesis that there is a relationship between the study variables
The hypothesis that there is no relationship between the study variables
The wrong hypothesis
The hypothesis that the research will not produce a statistically significant result
The hypothesis that there is no relationship between the study variables
Which of the following definitions best applies to the term ‘statistical significance’?
Select one:
The results of a study are applicable to a selected population
The results of a study are unlikely to have arisen by chance alone
The results of a study are not affected by chance
The results of a study are likely to be accurate
The results of a study are within expected limits
The results of a study are unlikely to have arisen by chance alone
Which of the following study designs most accurately describes a cohort study?
Select one:
A study that compares two groups of 4-year olds with similar characteristics: one group is given a drug and the other a placebo and the growth of each is measured after this intervention
A study that compares a group of children whose heights are below the 10th centile with a group of matched controls of normal height, aiming to identify possible causative factors
A study that looks at all children born at one hospital in 1 year and measures their height at intervals up to 4 years of age
A study that compares the height of a group of 4-year olds living near a nuclear plant with the height of a group of 4-year olds who live elsewhere
A study that aims to establish the normal height of 4-year old children by measuring heights at school entry
A study that looks at all children born at one hospital in 1 year and measures their height at intervals up to 4 years of age
Which one of the following best describes the term ‘external validity’?
Select one:
The consistency of a measure used on two separate occasions
The agreement between two raters using the same test at the same time
The extent to which one can appropriately apply the results to other populations
The level of agreement between two or more raters using the same test on two or more separate occasions
The level of consistency between two separate halves of the same test
The extent to which one can appropriately apply the results to other populations
What is the difference between a Case-control study and a Cohort study?
Case control - take 2 groups (one with a disease and the other without i.e. the control), review records to see who has been exposed to something that may have caused the disease and who hasn’t (both groups have ‘exposed’ and ‘not exposed’), it’s retrospective
Cohort study - look at study participants who are both currently exposed and not exposed to a risk factor, and evaluate the outcome in the future i.e. it’s longitudinal
How is number needed to treat calculated?
1/difference in intervention (chances of something happening before intervention - chances of it happening after intervention)
e.g. two groups, one given a drug and the other not. if 1/3 in the group with the drug die, and 1/2 in the group without the drug die, you do the following…
NNT = 1/(0.5 - 0.33)
How is relative risk calculated?
RR = absolute risk of an event happening in the treated group/absolute risk of an event happening in the control group
