EPIDEMIOLOGY DEFINITIONS EXAM
QUESTIONS AND ANSWERS
case fatality rate - ANSWER-the CIR of death among those with the disease
relative risk - ANSWER-the relative probability of the event in the treatment group
compared to the control group
relative risk reduction - ANSWER-the proportion of the baseline risk that is removed by
therapy
absolute risk reduction - ANSWER-the difference in absolute risk between the control
and treatment groups
number needed to treat - ANSWER-the number of patients who would need to be
treated to prevent an adverse event over a specific period of time
number needed to harm - ANSWER-the number of patients who would need to be
treated before an adverse event occurs over a specific period of time
PAR - ANSWER--represents the excess disease in the population that is caused by the
risk factor
-proportion of the total incidence in the population that is attributable to the risk factor
PARF - ANSWER-represents the fraction of total disease in the population that is
attributable to a risk factor
OR - ANSWER-ratio of the odds of exposure in the cases divided by the odds of
exposure among the controls
systematic error - ANSWER-bias; any process that acts to distort data or findings from
their true value
random error - ANSWER-variation that is due to chance
hypothesis testing - ANSWER--significance testing
-concerned with making a decision about a hypothesized value of an unknown
parameter
-involves the use of a p value
-views experimentation as decision making
estimation - ANSWER--concerned with estimating the specific value of an unknown
parameter
-involves the use of the confidence interval
QUESTIONS AND ANSWERS
case fatality rate - ANSWER-the CIR of death among those with the disease
relative risk - ANSWER-the relative probability of the event in the treatment group
compared to the control group
relative risk reduction - ANSWER-the proportion of the baseline risk that is removed by
therapy
absolute risk reduction - ANSWER-the difference in absolute risk between the control
and treatment groups
number needed to treat - ANSWER-the number of patients who would need to be
treated to prevent an adverse event over a specific period of time
number needed to harm - ANSWER-the number of patients who would need to be
treated before an adverse event occurs over a specific period of time
PAR - ANSWER--represents the excess disease in the population that is caused by the
risk factor
-proportion of the total incidence in the population that is attributable to the risk factor
PARF - ANSWER-represents the fraction of total disease in the population that is
attributable to a risk factor
OR - ANSWER-ratio of the odds of exposure in the cases divided by the odds of
exposure among the controls
systematic error - ANSWER-bias; any process that acts to distort data or findings from
their true value
random error - ANSWER-variation that is due to chance
hypothesis testing - ANSWER--significance testing
-concerned with making a decision about a hypothesized value of an unknown
parameter
-involves the use of a p value
-views experimentation as decision making
estimation - ANSWER--concerned with estimating the specific value of an unknown
parameter
-involves the use of the confidence interval
