Public and Preventative Health Flashcards
infant mortality rate
number of reported deaths among children <1 year of age during a given time period divided by the number of reported live births during the same time period and expressed as per 1000 live births per year
incresing the sample size decreases the probability of ____ but does not alter the risk of ___
incresing the sample size decreases the probability of TYPE I AND II ERROR but does not alter the risk of BIAS/CONFOUNDING
berkson’s bias
occurs in a case-control study using hospitalized controls, as they may not be representative sample of the population
information bias
the way in which information is collected about study participants is inadequate.
recall bias
when individuals with disease may be more likely to incorrectly recall/believe they were exposed to a possible risk factor than those who are free of disease.
sensitivity calculation
TP/TP+FN
aka true positives/ all the diseased people, whether they tested positive or not (falsely negative)
specificity
TN/ (TN+ FP)
what is likely hood ratio
likelihood that a given test result would be expected in a patient with disease compared with the likelihood that the same result would be expected in a patient without disease.
LR+ indicates how much the probability of disease increases if the test is positive.
LR- indicates how much the probability of disease decreases if the test is negative
LR+ calculation
indicates how much the prbability of disease increases if the test is positive
LR+ = sensitivity/ (1-specificity)
LR-
indicates how much the probability decreases if a person tests negative.
LR= (1-sensitivity)/(specificity)
positivie predictive value
proportion of people with a positive test who have the disease
PPV = (TP)/ (TP+FP)
Negative predictive value
proportion of people with a negative test, who really don’t have the disease.
NPV = (TN)/(TN+FN)
efficacy vs effectiveness
efficacy: the extent to which a specific intervention produces a beneficial result nder ideal conditions (RCT)
effectiveness: measures the benefit of an intervention under usual conditions of clinical care: considers both the efficacy of an intervention and its actual impact on the real world.
Odds ratio of a case-control study
OR: (A/C) / (B/D) = (AD/BC)
number needed to treat
NNT= 1/ (ARR)
where arr= absolute rate reduction = CER-EER
CER is control group event rate
EER is experimental group event rate.
prevalence:
#cases/total population
aka burden of disease
attack rate
number exposed individuals who became ill/total number of people exposed.
If the absolute rate of disease among smokers is 10/1000, and amongst non smokers it is 1/1000, what is relative risk and attributable risk?
RR=10 (ratio of the probability of the event in the exposed group compared to the non-exposred group) aka 10/1.
Attributable risk is the number of cases of a disease among exposured individuals that can be attributed to that exposure aka incidence (exposed) - incidence (unexposed)
therefore 10-1 = 9. 9 per 1000 persons per year.
tf case-control designs is better for studying rare diseases than the cohort design.
true; A COHORT STUDY NEED TO BE very large to ensure that enough cases of the rare disease develop.
health promotion
enabling peopel to increase control over and to improve their health.
