Prob. and Stats. Flashcards
What are the steps to Epi Studies?
- Define Question
- Determine Ideal approach
- Discern Sample Sizes
- Draft Protocols
- Enroll Subjects
- Collect Data
- Analyze Results
What are the 2 types of errors in studies?
- Random Error: due to chance
2. Systematic Error: due to Bias
A random error is the result of…
fluctuations around a true value bc of sampling or measuring variability
Statistical inference deals with…
random error
An error that is inherent to the study method being used and results in a predictable and repeatable error for each observation is…
a systemic error due to Bias
What estimates the likelihood that a study result was caused by chance resulting in unpredictable elements?
Tests of Statistical Inference
What is something that happens unpredictably w/out discernable human intention or with no observable cause?
A chance Occurrence
If you measure something over and over again and get slightly different measurements each time AND a few measurement may be extreme, this is called…
random variation
What estimates how much random variation there is in your measurements?
Confidence Intervals
T/F - Confidence Intervals can tell you something about the sample size.
True
A confidence interval is a range of values where…
the true value of our measurement could be found.
What is used to estimate whether the measure was likely to have been caused by CHANCE or not?
P-value
Using a P-value, you use a distribution of association values from…
a hypothetical pop. where there was no association.
The measured association is considered statistically significant if it is _____% of the values from many samples from the hypothetical distribution.
> 95%
If you read this statement in a journal article, how would you interpret it?
“Prevalence of disease was 8%”, 95% CI: 4% - 12%
Interpretation:
The estimate of the prevalence from the study was 8% and one is 95% confident the true prevalence lies somewhere btwn 4.0% and 12%.
