NCS Statistical Analysis Flashcards
what are common incorrect assumptions in statistics
you can use popular comparison tests aka t tests
groups are equal at baseline
groups are normally distributed
what are the 4 types of data
nominal, ordinal, interval, ratio
male or female is an example of what kind of data
nominal data
why is nominal data not great for clinical research
it is less sensitive and more difficult to demonstrate significant change
pain NRS or MMT grades are examples of what kind of data
ordinal data
mile markers or temperature in C or F are examples of what kind of data
interval data
weight, temperature in K, 0-100% scoring on a test are examples of what kind of data
ratio data
what type of data is the easiest and most sensitive
ratio
Bob collects data for his study, this is an example of what kind of data
primary data
Bob collects data for his study. A few years later, he then uses that same data for another study. this is an example of what kind of data
secondary data
Bob is looking to find out if there is a trend between patient admissions and adequate staffing in the ED over the past 5 years using EMR. This is an example of what kind of data
secondary data
what is continuous data
ratio or interval data
what is categorical data
ordinal or nominal data
what are the parametric assumptions
observations are independent
the data is normally distributed
variance is the same within groups
can only be used for ratio or interval data
true or false: it is easy to demonstrate meaningful effect sizes in nonparametric data
false - it is easier in parametric data
Tyler falls into the 75th percentile of students in his cohort. this is an example of parametric or nonparametric data
nonparametric (ranks/proportions)
according to central limit theorem, a sample distribution becomes more normal or abnormal as the sample size increases?
abnormal
according to central limit theorem, at what sample size/n can you not assume normal distribution
n > 30
you are looking to determine if there is a significant difference between data sets, what tests can yo u use
kolmogrov-smirnov or shapiro-wilks
Bob is conducting a study for a new intervention. His new intervention demonstrates clinical improvement but he does not recruit enough participants to reject his hypothesis that it is better than the standard of care. This is an example of what kind of error
type 1 error
Bob is conducting a study for a new intervention. His new intervention is not better than the standard of care but in his analysis he chose the wrong test and it produced a statistically significant finding. This is an example of what kind of error
type 2 error
Bob is analyzing nonparametric data using a test of proportions. what test should he use?
Chi squared
Bob is analyzing outcomes for an intervention group and control group that was not matched, what should he use if the data is normally distributed
parametric t test
Bob is analyzing outcomes for an intervention group and control group that was not matched, what should he use if the data is not normally distributed
nonparametric mann whitney u test