Exam 1 Flashcards
What is epidemiology
the study of disease among groups with focus on risk factors
what is a risk factor
something present in a population that increases their chance of disease
Morbidity
the presence of disease in a population
Mortality
cause & rates of death in a population as well as life expectancy
what do rates do
helps us quantify how often a disease occurs in a population
what are incidence rates
a measurement of how many healthy people die in a population over a given time period
example: CHD 125 causes/ 1000 men 55-64
what is a mortality rate
a measurement of how many people die in a population over a given time period
what is a prevalence rate
a measurement of how many people have a specific disease or behavior at a particular point in time
example: 23.7% of adults get no leisure activity
what is risk difference?
attributable risk; is an estimate of the risk attributed to a risk factor
what is relative risk?
Ratio of the exposed group ( sedentary) to the risk in the unexposed group (active)
What is attributable risk?
The amount of disease burden in population that results from a potentially modifiable risk factor
What are Crude rates
they are based on total population
cases / population
what are specific rates?
Based specifically to a population characteristic
cases in female / female population
What is a standardized rates?
Based on age or gender
cases /population adjusted for age/gender
what is a age adjusted rate?
standardized rates by age
what is the independent variable in this class
physical activity
what is the dependent variable in this class?
Medical condition
What is the cross-sectional research design?
it measures risk factors & diseases simultaneously ( no time )`
What is the case-control study design?
compares people with a disease ( cases ) against people without the disease (controls )
matched by:
age
gender
race etc..
What is the prospective cohort design?
a type of observational study focused on following a group of people (called a cohort) over a period of time, collecting data on their exposure to a factor of interest.
what is the randomized control trial?
clinical trial
Randomly assigned either an experimental or control condition
(Mills canons)
what is the temporal sequence between inactivity and disease
pa is before disease
( Mills Canon)
what is the strength of association between Pa and disease
long and clinically measured
( mill Canon)
what is consistency
Association across studies
( Mills Canon )
Base response between pa and disease risk
Disease risk increase with stronger exposure to risk
( Mills Canon)
What is the biological plausibility
explains how pa affects disease risk
What is confounding?
distortion of causal association by other factors
Who is John Snow
The Father of Epidemiology
- 1854 pump handle: traced chlorate back to the well
Focus of Epidemiology
- Measure disease frequency
- assess distribution of disease
- Form hypothesis including causal and preventable factors
What document contains the 10 Year national objectives for PA
Healthy people 2020
What were limitations of early PA and disease studies
Energy expenditure can differ widely in same job - may not measure leisure time
did not adjust for cofounders such as diet or genetics
What documentation contains the policy details about national pa and health
National physical activity plan 2010
Jeremy Morris
conducted the first study of pa epi
-London bus study
London bus study
- Prospective Cohort Study
Compared rates of coronary disease between drivers & conductors
NHANES
National health and Nutrition examination survey
- questionnaire are looking at health by population
BRFSS
Behavioral risk factor surveillance
- phone calls given to random people with in the population
Ralph Paffenbarger
San fran longshoreman study, began in 1951 as a population based examination of CHD in men who preformed strenuous, moderate, light task working
Rod dishman
From UGA and named to national committee that helped create the 2008 PA guidelines for Americans
Steven Blair
Aerobics center longitudinal study
ongoing how diet and pa factors affect mortality and disease risk
Frank speizer
Nurse Health Study (Harvard and womens Hospital )
- longest running cohort study of women
- studied the association between oral contraceptives, cigarettes smoking and risk of chronic disease
Walter Willet
Health professional studies
- he started many follow up studies with male health professionals after the nurses health study
First government released pa guidelines
2008 aerobic pa guidelines for adults
Odds ratio
calculated from prevalence
study: cross sectional and randomized
Effect modification
- a situation in which two or more risk factors modify one another’s effects on an outcome
What statistics related to risk factor and disease found in a 2 X 2 table can we compute?
incidence rates, AR, RR, PAR, and OR
Odds Ratio
Compares the likelihood of an event between two groups
How do we interpret RR (risk ratio) and OR (odds ratio)?
If risk of disease is the same in groups exposed and unexposed → RR & OR = 1.0 As the impact of the risk factor increases → the relative risk increases Use the 95% confidence interval → makes RR or OR meaningful (1.0 cannot fall between values
How is PA different from exercise?
Physical activity- any bodily movement produced by skeletal muscle that results in energy expenditure * Exercise- planned physical activity that is used for fitness and health purposes
four domains
Frequency
intensity
type
time
Indirect calorimetery
estimating energy expenditure from oxygen consumption and CO2 production by applying the caloric equivalent of oxygen
5kcal per liter of O2 consumed
Doubly labeled water
ingestion of water w/ 2 stable isotopes of single H and O best overall measure of total EE
- accurate but very expensive
- TEE only
Direct observation
Yields useful pa data
used
- frequently w/ studies on children
- Extensive amounts of time needed
Heart rate monitors
- objective but indirect method
- linear relationship between HR and EE
- Can provided estimates of EE
- Influential factors
- Hr lags behind changes in movement and intensity
Pedometers
- cost - effective
- measures volumes of physical activity
Accelerometers
Monitors movement in a specific plane - measures freq and intensity
BRFSS
Telephone interview - adults only
annual collection of data
NHIS
Personal interview - adult and children
annual collection of data
NHANES
Interview examination
collect data for 2+ years
YRBSS
School based survey
high school students
collected data every 2 years
within the us what region has the highest rates for preventable deaths
southeast
key factors that drive premature death according to 210 data
poor diet
lack of exercise
Harvard alumni study
LTPA and risk of all cause mortality
What is MET
metabolic equivalent
- the energy expenditure in kilocalories
Met to intensity
1.0 → sleep/rest *3.3 → moderate *6.0 → vigorous
current pa guidelines for health in the U.S
150 minutes moderate aerobic PA > 3 mets
Absolute intensity for measuring PA
work rate expressed as an absolute value that is the same for all people
relative intensity for measuring pa
work rate in relation to maximal intensity, aerobic capacity or workload
what is the life expectancy of the u.s and how does it compare to other developed countries
men 75.6
women 80.8
we are among the lowest
what are the leading causes of mortality in the us
heart disease
cancer
cerebrovascular disease (stroke)
