Collecting the Evidence Flashcards
When constructing a clinical question, what factors need to be considered?
- Patient/Problem,
- Intervention,
- Comparison to intervention (if any),
- Outcome
Describe the anatomy of a good question?
- Define precisely whom the question is about?
- Define which option you are considering and a possible comparison.
- Define desired/undesired outcome.
What are some of the information resources?
- Systematic reviews/ meta analysis,
- Clinical practice guidelines,
- Original article containing primary research data
What are simple rules for navigating a clinical question?
1) Start with cochrane reviews, NICE and SIGN guidelines.
2) Then use MedLine (eg, PubMed)
What are the different type of hypothesis?
Null hypothesis - Where two data are from the same population and not different.
Alternative hypothesis - Two sets of data are from different populations and are different
What are the different types of quantitative data?
Discrete - Can only have certain numerical values.
Continuous - Do not have discrete steps (height and weight)
Describe nominal and ordinal variables?
(more data types)
Nominal - eg, alive/dead, blue or green etc.
Ordinal - Objective and subjective
What is the P value?
The probability that the null hypothesis is correct. When equal to one is means it is certain.
What does it mean if the P>0.05?
Weak evidence against the null hypothesis. Data is consistent with the null hypothesis
What does it mean if the P<0.05
Means there is moderate evidence against the null hypothesis in favour of the alternative. The smaller the value then the stronger the evidence
What is the Type 1 errors?
Rejecting the null hypothesis when it is true (false positive) meaning P is small.
what is a type 2 wrrors?
Not rejecting the null hypothesis when it is false (false negative) - meaning there is no effect when there is
What is power?
The power of a test is its ability to reject the null hypothesis when it is false. (Capacity to detect an effect if one is present)
