EBM year 1 Flashcards
How to display a categorical variables
frequency tables, bars charts and pie charts
Three types of variables
categorical, binary and numerical
How to display binary variables
x/y plot
only has two variables
How to display numerical variables
line plots, bar charts, scatter-plots and stem and leaf plots and histograms
What are the descriptive statistics for binary variables
incidence rate, prevalence and risk
equation for prevalence
number with a disease at a particular point in time / total number in population at that time
equation for risk
number of new cases of disease in a time period / number initially free from disease
equation for incidence rate
number of new cases of disease/ number initially free from disease x time interval
What are the descriptive statistics for numerical variables
standard deviation and 95% reference range
how do you calculate the reference range
(mean -1.96) x SD
what is a normal distribution
normal bell-shaped graph, symmetric around the mean
What characteristic do epidemiologists examine
person, place and time
when looking at person, place and time what are they looking for
differences
similarities
correlations
what is a cross-sectional study
looks at data from a population at one specific point in time
defining characteristics of cross-sectional study
study takes place at a single point in time
does not involve manipulating variables
allows researchers to look at multiple characteristics at once
often used to look at prevailing characteristics in a given population
