Biostatistics Flashcards
What does ANCOVA stand for??
Analysis of covariance
What does ANOVA stand for?
Analysis of variance
What are two types of random variables?
Discrete variables (including dichotomous and categorical) and continuous variables
What are variables that have a limited number of values within a given range? (Discrete or Continuous)
Discrete
What are variables that can take on any value within a given range? (Discrete or Continuous)
Continuous
Are nominal and ordinal variables discrete or continuous?
Discrete
What are discrete variables that are classified into groups, but have no order or rank?
Nominal variables
What are discrete variables that are ranked in a specific order, but with no consistent size or magnitude of difference between ranks?
Ordinal variables
Sex, mortality, disease presence, race, and marital status are examples of what type of discrete variables?
Nominal
The functional status of patients with heart failure, classified in increasing order of disease severity, is what type of discrete variable?
Ordinal
What are three visual methods of describing data (visuals for descriptive statistics)?
Frequency distribution, histogram, and scatterplot
What is it called when you convert data to their log values and calculate the mean, which results in the conversion of a skewed to a normal distribution?
Geometric mean
Which measure of central tendency is more appropriate if you have significant outliers in your data, mean or median?
Median
Name the three measures of central tendency
Mean, median, and mode
Name three measures of sample spread or sample variability
Standard deviation, range, and percentiles
What does standard deviation measure?
Variability about the mean; SD is the most common measure used to describe the spread of data
Should means or SDs be reported with ordinal data?
No
By the empirical rule, what percentage of sample values are within +/- 1 standard deviation? +/- 2 SDs?
68% and 99%
What is the coefficient of variation?
The ratio of the standard deviation to the mean; gives an idea of the spread of the data
What are conclusions or generalizations made about a population from the study of a sample of that population?
Inferential statistics
What is it called when there are two possible outcomes, the probability of obtaining either outcome is known, and you want to know the chance of observing a certain number of successes in a certain number of trials?
Binomial distribution
What is it called when you are counting events in a certain period of observation, the average number of counts is known, and you want to know the likelihood of observing a various number of events?
Poisson distribution
Name two types of discrete distributions
Binomial and Poisson
