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
Attributable risk
Difference in rosk in exposed and unexposed grouops (risk that is attributable to exposure)
Relative risk
Incidence in exposed group divided by incidence in nonexposed group
Results of hypothetical study found an association between ASA intake and risk of heart disease. How do you interpret RR of 1.5?
Pts who took ASA rsk of heart disease was 1.5 times that of pts who did not take ASA
Odds ratio
Cohort: odds of developing disease in exposed group divided by odds of developing disease in nonexposed group
Case control: odds taht cases were exposed divided by odds that controls were exposed
Cross-sectional: odds that exposed group has disease divided by odds that nonexposed group has disease
Results of hypothetical study found an association between ASA intake and risk of heart disease. How do you interpret OR of 1.5?
Pts who took ASA, odds of acquiring heart disease were 1.5 times those who did not take ASA
Which pts do you initiate colorectal cancer screening early
Pts with IBD, FAP, HNPCC
Have first degree relatives with adenomatous polyps (<60 yrs of age) or colorectal cancer
Most common cancer in men and most common cause of death in men
Cancer: prostate
Death: lung
Percentage of cases within 1 SD of mean? 2 SD? 3 SD?
68%, 95.4%, 99.7%
Birth rate
Live births per 100 population in 1 year
Mortality rate
Deaths per 100 population in 1 year
Neonatal mortality rate
Death from birth to 28 d per 100 live births per year
Infant mortality rate
Number of deaths from birth to 1 yrper 1000 live births (neonatal + postnatal mortality) in 1 yr
Maternal mortality rate
Number of deaths during pregnancy to 90 days postpartum per 100,000 live births in 1 yr
