Rapid Review Epidemiology Flashcards
How do you interpret the following 95% CI for RR of 0.582: 95% CI 0.502, 0.673
These data are consistent with RR ranging from 0.502 to0.673 with 95% confidence
Bias introduced into study when clinician is aware of pt’s Tx type
Observational bias
Bias introduced when screening detects a disease earlier and this lengthens the time from Dx to death
Lead time bias
If you want to know if geographical location affects infant mortality rate but most variation in infant mortality is predicted by socioeconomic status, than socioeconomic status is a
Confounding variable
Proportion of people who have the disease and test positive is the
Sensitivity
SEnsitive tests have few false negatives and are used to rule — a disease
out
PPD reactivity is used as a screening test because most people with TB (except those who are anergic) will have a positive PPD. HIghly sensitive or specific?
Highly sensitive for TB. Screening tests with high sensitivity are good for disease with low prevalence
Chronic disease such as SLE- higher prevalence or incidence?
Higher prevalence-
number of cases in given time period/total # in population at that time period
Epidemic such as influenza- higher prevalence or incidence?
High incidence
number of new cases/number of ppl in population at risk
Difference between incidence and prevalence?
Prevalence: percentage of cases of disease in a population at 1 snapshot in time
Incidence: percentage of new cases of disease that develop over given time period among the total population at risk
Cross sectional survey- incidence or prevalence
Prevalence
Cohort study- incidence or prevalence
Incidence and prevalence
Case-control study- incidence or prevalence
Neither
Describe a test that consistently gives identical results, but results are wrong
High reliability/precisions, low validity/accuracy
Difference between cohort and a case control study
Cohort: calculate RR, incidence and/or OR
Case-control: calculate OR- estimate of RR when disease prevalence is low