CDCs Flashcards
In the definition of epidemiology, distribution refers to what?
who, when, where
In the definition of epidemiology, determinants generally includes
agents, causes, risk factors, sources
The hallmark feature of an analytic epidemiologic study is what?
use of an appropriate comparison group
A cohort differs from a case control study in that….
subjects are enrolled or categorized on the basis of their exposure status in a cohort study but not in a case study
The epidemiological triad of disease causation refers to…
agent, host, environment
A reservoir of an infectious agent can be…
an asymptomatic human, a symptomatic human, an animal, the environment
usually 40-50 cases per week, last week was 48 cases
endemic
Fewer than 10 cases per week, last week 1 case
sporadic
Usually no more than 2-4 cases per week, last week 13 cases
outbreak
A propagated epidemic is usually the result of what type of exposure?
person-person
mode
value that occurs most often
Median
has half the observations below it and half above it
Mean
statistically closest to all of the values in the distribution
Geometric mean
statistically closest to all of the values in the distribution on a log scale
The measure of central location generally preferred for summarizing skewed data?
median
Meaasure of central location generally preferred for additional statistical analysis
Mean
Measures of spread
interquartile range, range, standard deviation, variance
Measure of spread most affected by one extreme value
range
Measure of central location most commonly used with the interquartile range
median
Measure of central location most commonly used with standard deviation
arithmetic mean
Relationship between standard deviation and variance
standard deviation is square root of variance
Primary use of the standard error of the mean
confidence interval
Examples of frequency measures?
birth rate incidence, mortality rate, prevalence
women in A who died from lung cancer in 2004 / women in A who did from cancer in 2004
ratio or proportion
Women in A who died from lung cancer in 2004/ women in A who died from breast cancer in 2004
ratio
women in A who died from lung cancer in 2004/ estimated women living in A on Jul7 1, 2004
ratio and mortality rate
Measure of risk
incidence
generally preferred for chronic diseases without clear date of onset
prevalence
Used in calculation of risk ratio
incidence
affected by duration of illness
prevalence
number of children <365 days of age who died in country A in 2004/ number of live births in country A in 2004
ratio, mortality rate
number of deaths due to septicemia among men aged 65-74 years in 2004/ estimated number of men aged 65-74 years alive on July 1, 2004
age specific mortality rate, cause specific mortality rate, sex specific mortality rate
Vaccine efficacy measures what?
the proportionate reduction in disease among vaccines
Tables ad graphs are important tools for which tasks of an epidemiologist?
data summarization, data analysis, data presentation
Define table shell
table with labels and title but without data
WHen is the best time to create table shells?
as part of planning the study
Define cumulative frequency curve
plotted curve usually begins in the lower left corner
Scatter diagram
requires more than one variable, two continuous variables
Number of cases of dog bites over time
histogram and line graph
NUmber of cases of dog bites by age group and sex of the victim
grouped bar graph
number of cases of dog bites by breed of the dog
pie graph
Number of cases of dog bites per 100,000 population over time
line graph
Public health surveillance can be described as which of the following?
a method to monitor occurrences of public health problems
Vital statistics are important sources of data on which of the following?
mortality
state-based with subsequent reporting to CDC
notifiable disease surveillance
Focused on identifying individual cases
notifiable disease surveillance
Can monitor trends over time
both notifiable disease surveillance and surveillance for consumer product related injuries
Complete, unbiased reporting
neither
Surveillance detected 23 of 30 actual cases of disease
sensitivity
Of 16 statistically significant aberrations detected by syndromic surveillance, only one represented an actual outbreak of disease
predictive value positive
