Exam 2 chapters 17/18 Flashcards
what is epidemiology
is defined as the study of the distribution and determinants of health related states or event in specified populations, and the application of this study to the control of health problems
what is in epidemiology
distribution
determinant
application
distribution
frequency- prevalence, incidence, mortality rates
patterns- person, place, time
determinant
defined characteristics- associated with change in health
application
translation- knowledge to practice
Frequency
physical activity measurements definition
relates to the number of times per week or year that one is physically active
Duration
physical activity measurements definition
refers to the time spent in a specific activity as hours or minutes per session
intensity
physical activity measurements
refers to the difficulty of an activity and is generally classified as light, moderate, or vigorous.
Dose
physical activity measurements definition
refers to combination of the frequency, intensity, and duration of physical activity and is expressed as kcal/day, MET- hour/day, minutes on a treadmill graded exercise test, or other units.
physically active
physical activity measurements definition
is a global term that is defined as all movements produced by the the contraction of skeletal muscle that substantially increase energy expenditure.
exercise
physical activity measurements definition
is planned, structured, and repetitive bodily movements done to improve or maintain one or more components of physical fitness
physical fitness
physical activity measurements definition
is a multidimensional concept associated with a set of attributes that people have or achieve that relates to the ability to perform physical activity
leisure
physical activity measurements definition
is a concept that includes the elements of free choice, freedom from constraints intrinsic motivation, enjoyment, relaxation, personal involvement, and opportunity for self expression
volitional
physical activity measurements definition
physical activity refers to activities done for a purpose in either structured or unstructured settings.
spontaneous
physical activity measurements definition
physical activity refers to brief periods of movement that results in energy expenditure through fidgeting, gesticulation or unintentional short accumulated periods of movement
epidemiological study designs
descriptive analytical cross sectional designs ecological cohort studies
ecological designs
use existing data sources for both exposure and disease outcomes to compare and contrast rates of disease by specific characteristics of an entire population
what are advantages of a cohort study? p. 335
1 the temporal sequence between exposure and outcome is clearly defined. exposure assessment are obtained before disease onset, this is the primary
2 good for rare exposures.
3 good fro understanding the multiple effects of a single exposure
what are some disadvantages of cohort?
1 you have to keep track of large portion of people and can create bias in the study
2 also there might be too much data and it isnt going to go through
3 criteria for establishing cause and effect
1 the cause must precede the effect in time
2 the cause and effect must be correlated with each other
3 the correlation between cause and effect cannot be explained by another variable
application of this logic is… p. 346
1 selection of a good theroetical framework
2 use of appropriate participants
3 application of an appropriate experimental design
4 proper selection and control of the independent variable ( treatment)
5 appropriate selection and measurement of the dependent variable
6 use of the correct statistical model and analysis
7 correct interpretation of the results
threats to internal validity
History maturation testing instreumentaion statistical regression selsction biases experimental morality selection expectancy
History
threats to internal validity
events that are not part of the treatment
Maturation
threats to internal validity
processes within the participants that operates as a result of time passing ( hunger, aging, fatigue)
Testing
threats to internal validity
the effects of one test on subsequent administrations of the same test
instrumentation
threats to internal validity
changes in instrument calibratin, including lack of agreement within and between observers
statistical regression
threats to internal validity
the fact that groups selected based on extreme scores are not as extreme on subsequent testing
selection bias
threats to internal validity
choosing comparison groups in a nonrandom manner
experimental mortality
threats to internal validity
loss of participants from comparison groups fro nonrandom reasons
selection maturation interaction
threats to internal validity
the passage of time affecting one group but no the other in nonequivalent group designs
expectancy
threats to internal validity
experimenters or testers anticipating that certain participants will perform better
- OR influencing them
controlling threats to internal validity
- randomization
- real randomization
- matched pairs ( non matched groups )
- randomizing treatments or counter balancing
- placebos
- blind setups
- double blind set up
- reactive effect of testing: eleiminat pretest
- instrumentation
- calibration and test reliability
- halo effects ??
- just keeping subjects
threats to external validity
- reactive or interactive effects of testing
- interaction of selection bias and the experimental treatment
- reactive effects f experimental arrangements
- multiple treatment interference
reactive or interactive effects of testing
threats to external validity
the pretest may make the particiapnt more aware of or sensitive to the upcoming treatment. as a result the treatment is not as effective without the pre test.
interaction of selection bias and the experimental treatment
(threats to external validity )
when a group is selected on some characteristic, the treatment may work only on groups possessing that characteristic
reactive effects f experimental arrangements
threats to external validity
treatments that are effective in constrained situation may not be effective in less constrained settings
multiple treatment interference
threats to external validity
when participants receive more than one treatment, the effects of previous treatments may influence subsequent one
controling threats to external validity
- selecting from larger populations
- participants
- treatments
- situations
- ecological validity: does the setting capture the essence of the real world ?
review journals ( there are 2)
- pabcio
- and the other one
