Intro to Epidemiology Pop-based health-McFarland Flashcards
What are the important components of critical review of medical literature?
study question study design exposure outcome & measurement inclusion & exclusion criteria analysis of results bias & limitation validity/generalizability
What is descriptive epidemiology?
distribution: person, place, time
What is analytic epidemiology?
determinants: risk & protection
Surveillance Case Studies Cross-sectional Ecologic Which type of study?
descriptional–>distribution of disease
Which type of study includes looking at data collected?
analytic studies, not descriptive
these are also the types of studies that look at data collected.
clinical trial, community fall into which category?
Analytic Experimental
Cohort: prospective, retrospective
Case Control
Which type of category does this fall into?
Analytic Observational
TFAnalytic describes distribution of disease.
F. Determinants of disease
A cohort study is best for looking at which type of data set?
can examine many outcomes
What is prevalence when talking about disease frequency?
existing cases of a disease/# in the total population
What is the cumulative incidence w/ respect to disease frequency?
new cases of a disease/# in candidate population
What is incidence rate w/ respect to disease frequency?
new cases of a disease/person-time of observation
What are some examples of relative measures?
prevalence ratio
risk ratio
rate ratio
odds ratio
What are some examples of absolute measures?
prevalence difference
risk difference
rate difference
T/F You can calculate cumulative incidence rates in case control studies.
False. But you can calculate odds ratio
What is an odds ratio?
ratio of the probability of an event occurring to that of it not occurring
OR
prob of event occuring/1-probability of event not occurring
What is exposure ratio?
odds of being exposed among cases/odds of being exposed among controls
What are some guidelines for causality?
strength of association temporality biological gradient/dose response plausability consistency
what must you do when evaluating bias?
identify its source
estimate its magnitude
assess its direction
What are some important forms of bias?
selection bias information/observation bias lead-time bias hawthorne effect repeat-testing bias
What are some forms of selection bias?
uneven selection of subjects
loss to follow up
diagnosis of study subjects according to their exposure or disease status
healthy worker effect-everyone there is healthy!
What is information bias?
recall-different levels of accuracy in the info provided by compared groups
interviewer–systematic difference in soliciting, recording or interpreting information
What is lead time bias?
all cases are not detected at the same stage of disease
What are some forms of bias found in this study?
selection bias-only ACS survivors
loss to follow up
What is Hawthorne effect?
if a subject knows they are being watched, their behavior will change
What is repeat testing bias?
fatigue or memory of questions will alter results
What are the 3 requirements that must be met for a confounding variable?
- associated (non-causally or causally) with the exposure.
- associated (causally) with the coutomce, independent of the exposure
- not be an intermediate variable int he causally pathway
What is an example of a confounding variable?
diabetes associated w/ increased risk of dementia.
confounder: they are older!
What is the prevalence of heart disease in Nevada adults?
4% of adults have been diagnosed with it.
More common in:
black, older adults, individuals w/ incomes less than 24K
Several previous studies have identified differences in mortality b/w men & women with ACS. The authors suggest that most of these studies failed to adjust for clinical factors such as cofounders. Which of the following best explains why failure to adjust for clinical factors could have obscured the underlying true association?
A. Certain clinical factors are causally related to mortality and clinical factors are not associated w/ gender.
B. Certain clinical factors are causally related to mortality but clinical factors change over time.
C. Certain clinical factors are causally related to mortality & clinical factors vary by gender.
C.
Participants in this study were patients admitted to the hospital with a diagnosis of acute coronary syndrome. Which of the following best describes the advantage of only including patients with ACS?
A. increases internal validity of the study.
B. increases external validity of study.
C. increases sample size and power of the study
D. reduces bias
A.
p-values are <0.001
A. null hypothesis of no difference b/w men & women is rejected.
B. null hypothesis of no difference b/w men & women is accepted.
A.
