Clinical R&D Flashcards
These aim to collect, summarize and describe.
a) inferential stats
b) descriptive stats
b) descriptive stats
These allow conclusions about a larger population from a smaller study sample.
a) inferential stats
b) descriptive stats
a) inferential stats
This states that there is no difference between two groups
null hypothesis
a hypothesis which rejects an experimental hypothesis. It is the status quo.
null hypothesis
the average:
a) mean
b) median
c) mode
a) mean
the middle response in a sequence from lowest to highest
a) mean
b) median
c) mode
b) median
where there is an even number of scores, take an average of the middle scores to get this:
a) mean
b) median
c) mode
b) median
this is the best way to measure central tendency where there are extreme outliers
a) mean
b) median
c) mode
b) median
the most frequent score in a population of scores a) mean
b) median
c) mode
c) mode
these are measures of central tendency
mean
median
mode
these are measures of spread
range
interquartile range
standard deviation
This shows a tendency of spread from smallest to highest values; variability
a) range
b) interquartile range
c) standard deviation
a) range
this measure of spread shows the middle 50%
a) range
b) interquartile range
c) standard deviation
b) interquartile range (how many scores fall between 25-75%. It is less sensitive to extremes)
this measure allows you to infer results outside of your sample, if taken to at least 3 levels
a) range
b) interquartile range
c) standard deviation
c) standard deviation
T/F: if a P-value is less than 5%, a real difference exists
True
T/F: with a P-value of 0.1%, a real difference exists
False
This measures how likely the observed results are due to chance/random error
P-value
What are 3 factors that influence P-value?
magnitude of effect
sample size
variability
T/F: a larger sample increases the statistical power of a study
true
T/F: a lower magnitude increases the statistical power of a study
false
T/F: a lower variability increases the statistical power of a study
true
limits responses to categories, usually a choice of two (ex: yes/no, gender, age, occupation, height)
a) categorical
b) continuous
a) categorical
limits responses to a given range, usually a 0-10 scale (ex: blood pressure)
a) categorical
b) continuous
b) continuous
T/F: the lower the p-value, the more confidently we can reject the null hypothesis
true
T/F: p-value has to do with clinical significance
false: p-value determines statistical significance
what power variable is typically used in healthcare to determine if a difference does actually exist?
.80 = this means a study has an 80% chance of finding a statistically significant result (a p-value of less than 5%)
what group size is typically used per tx group to determine the power of a study?
40-50
this measures if the size of the result was large enough. If it is large, there is more statistical power.
magnitude of effect
this is the ratio of probability of an event occurring in an exposed group vs. the event occurring in comparison to a non-exposed group
relative risk
this measures levels of uncertainty
confidence intervals
T/F: a narrow confidence interval means a study is inadequately powered
F: a narrow confidence interval is well-powered
this indx how much your observed sample statistic may fluctuate if the same experiment is repeated a large number of times in the same sample
a) standard error
b) confidence interval
a) standard error
this indx the range that’s likely to contain the true population parameter
a) standard error
b) confidence interval
b) confidence interval
_______focuses on sample while ________focuses on population.
a) confidence interval/standard error
b) standard error/confidence interval
b) standard error/confidence interval
this type of stat helps determine if study results are affected by random error:
a) inferential stats
b) descriptive stats
a) inferential stats
in the example “56% of polled residents would vote in favor of the amendment +/-5%”, which part is the descriptive statistic?
56%
in the example “56% of polled residents would vote in favor of the amendment +/-5%”, which part is the inferential statistic?
+/- 5%
T/F: a small interquartile range means most of the data fell close to the median, this limits variability
T
this is often described as the average distance from the mean
standard deviation