Test 2 Flashcards
What should you ask after an epidemic is detected? (3 things)
Who is getting the disease?
When/Where is the disease occurring?
Why may the disease be happening?
What is Epidemiology?
The study of the distribution and determinants of disease frequency in human populations.
Scientific Process
- ) Generate an idea (observation)
- ) Develop a hypothesis
- ) Test a hypothesis (using good scientific methods)
- ) Develop a theory…test the theory
Prevalence Rate
current cases/population….how many people have a disease at a certain time
Incidence Rate
new cases/population/time frame….how many people are getting a disease in a certain time period
Common infectious diseases that kill quickly
high incidence, low prevalence
common infectious diseases that don’t kill but disable
high incidence, high prevalence
rare diseases that kill quick
low prevalence, low incidence
rare diseases that don’t kill but disable
low incidence, high prevalence
Present to future
Prospective study (longitudinal)
Looking to past to predict current
Retrospective (longitudinal)
Observational process used to generate hypothesis
“Descriptive” Epidemiological studies
Experimental process to test hypothesis
“Formal” Epidemiological studies
What is used to generate a hypothesis?
Observational processes
Describing what’s out there
Descriptive (form of observational)
Determines what came first (order of events)
Longitudinal study
Has a timetable
Longitudinal
No timetable
Cross-sectional
Does cross-sectional or longitudinal have more bias?
Cross sectional has more bias
Does cross-sectional allow us to determine cause and effect?
No
Is cross-sectional easy to preform
Yes
Group followed over a period of time
Cohort study (longitudinal)
Is a cohort study prospective or retrospective
Prospective
Most biased?
Cross-sectional
Who selects the level of exposure in cohort studies?
The subjects
Looking back to see what caused a disease
Case-control studies
What are case-control studies good with?
Rare diseases
Is case control retrospective or prospective?
Retrospective
Odds ratio used for…
Case-control studies
Relative Risk used for….
Cohort studies
Who picks the level of exposure for case-control studies?
The subjects
Bias associated with Randomized Control Trial
Dropout Bias
Bias associated with Cohort
Selection bias (those that perform issue of interest may perform other issues)
Bias associated with Case-Control
Selection and Recall bias
What is random error (pure chance) associated with?
Chronic diseases and small sample sizes
When true cause and effect is missed
False negative
When there is thought to be a relationship, but there is none
False positive
P-value
the probability that the observed result could happen by chance alone
p=.60 means?
60% chance of error
what is p-value influenced by?
quality of research data and if there is a true “cause and effect”
a>p
Statistically significant
a<p></p>
NOT statistically significant
Small p-value usually means…
Statistically significant
What is power?
probability of finding an effect if a true cause and effect does exist
How to increase power?
Increase sample size and have more accurate measures
Definitely know if it is a case, but some may be missed
Specific test
Definitely identify all positive cases, but some extras
Sensitive test
Increasing sensitivity will do what?
Decrease false negatives
Increasing specificity will do what?
Decrease false positives
What does a 95% CI mean?
95% confident predicted # is in the range
What is used to compare two continuous variables in 1 group?
Correlation (r=%related)
What is used to compare one continuous variable between 2 groups?
T-test
What is used to compare one continuous variable between multiple groups?
ANOVA
What is used to compare one categorical variable between 2 groups?
Chi-Square
What is used to compare multiple variables to a single continuous variable?
Multiple regression
What is used to compare multiple variables to a single categorical variable?
Logistic regression
Years of life lost from doing a certain behavior
Years of Potential Life Lost (YPLL)
Allows us to know the health status of our community
NCHS (National Center for Health Statistics)
Is NHANES (National Health and Nutritional Examination Study) self reported or direct observation?
Direct observation of physiological data
Is NHIS (National Health Interview Survey) self reported or direct observation?
Self reported thru phone survey of about 50,000 people
Is the BRFSS (Behavior Risk Factor Surveillance System) self reported or direct observation?
Self reported
What does the YRBS measure
behaviors of youth…supervised administration in class
What is the MMWR
Morbidity and Mortality Weekly Reports. Weekly reports on current health threats/issues
Are clinical trial prospective or retrospective?
Prospective and rigorous
Relative risk compares what?
Disease rates (used for cohort studies)
Odds ratio compares what?
exposure rate (used for case-control studies)
