Intro to Biostats Flashcards
What is a statistically significant P-value?
< 0.05
How do you determine if something is effective?
By determining if something is statistically significant.
What 2 factors should look for when interpreting statistics?
Precision
Consistency
What is meant by dichotomous outcomes?
“Yes and No” type of outcomes or “This or that”
e.g., did the patient experience hypotension?
did the patient experience NV?
What is the rule of thumb when it comes to the minimum number of events for dichotomous outcomes?
At least 300. Less than that information is likely to be insufficient.
What is the rule of thumb when it comes to the minimum number of events for continuous outcomes?
At least 400.
How precise is an outcome if it s statistically significant (P= < 0.05), but the number of events is less than 300.
It is not precise.
What is meant by consistency?
It means measuring the same patients’ results using the same instruments.
For example, assessing pain using visual analogue scores (VAS) to assess pain.
What is meant by precision?
It refers to the precision of the study as it relates to the number of people analyzed or the amount of information and whether there is sufficient to detect a precise estimate of the effect.
I.e., if there is not enough data, the study cannot be precise because it cannot accurately detect a precise estimate of the effect of an intervention.
This means the findings cannot be generalized even though it is statistically significant
What value are you assessing to assess consistency?
I 2 test, %
What is an acceptable I 2 test %?
< 50% - meaning the results are homogenous
What is meant by homogenous results?
Homogeneous results indicate that the results of the studies are similar or consistent with each other, and the variation between them can largely be explained by random chance.
In this case, the results are considered to be homogeneous, meaning there is little or no real difference between the studies
What is descriptive statistics?
The collection of data summarized in order to characterized features of its distribution
What is meant by heterogenous results?
Heterogeneous results: If the I² value is high (typically above 50% or 75%), it means there is significant variability between the studies, which is not due to chance.
This indicates that the studies’ results differ from each other for reasons (other factors) other than random variation, and the results are considered heterogeneous.
