Crude mortality rate
Calculated by dividing the number of deaths by the total population size
Cause-specific mortality rate
Calculated by dividing the number of deaths from a particular disease by the total population size
Case-fatality rate
Calculated by dividing the number of deaths from a specific disease by the number of people affected by the disease
Standardized mortality ratio (SMR)
Calculated by dividing the observed number of deaths by the expected number of deaths. This measure is used sometimes in occupational epidemiology. A SMR of 2.0 indicates that the observed mortality in a particular group is twice as high as that in the general population.
Attack rate
An incidence measure typically used in infectious disease epidemiology. It is calculated by dividing the number of patients with disease by the total population at risk. For example, attack rate can be calculated for gastroenteritis among people who ate contaminated food.
Maternal mortality rate
Calculated by dividing the number of maternal deaths by the number of live births.
Crude birth rate
Defined as the number of live births divided by the total population size
Crude birth rate
Defined as the number of live births divided by the total population size
Crude birth rate
Defined as the number of live births divided by the total population size
Standardized incidence ratio
A measure used to determine if the occurence of cancer in a small population is high or low relative to an expected value derived from a larger comparison population
Likelihood ratio – Interpretation
> 10: Strong evidence to rule in the disease 5-10: Moderate evidence to rule in the disease 2-5: Weak evidence to rule in the disease 0.5-2: No evidence to rule in or rule out the disease 0.2-0.5: Weak evidence to rule out the disease 0.1-0.2: Moderate evidence to rule out the disease < 0.1: Strong evidence to rule out the disease
Sensitivity analysis
Refers to repeating primary analysis calculations after modifying certain criteria or variable regions. The goal is to determine whether such modifications significantly affect the results initially obtained.
Net clinical benefit
The net clinical benefit or clinical usefulness of a medication is a measure of its potential benefit minus its potential harm. NCB needs to be viewed in light of the specific clinical situation.
Intention to treat (ITT)
The basic premise of ITT analysis is that participants in trials should be analyzed in the groups to which they were randomized, regardless of whether they received or adhered to the allocated intervention and regardless of whether they withdrew from treatment. The ITT principle holds that randomization is of paramount importance and that deviation from the original randomized groups can contaminate the treatment comparison. ITT analyses are performed to avoid the effects of crossover and dropout, which may break randomization and affect the outcome.
Incidence rate (IR)
The incidence rate (IR) or person-time rate is a measure of indicence that incorporates time directly into the denominator. A person-time rate is generally estimated from a follow-up study; for example, 1 woman followed for one year would contribute 1 person-time. IR is calculated as follows: IR = (Number of new cases of disease during a period)/(Total person-times contributed by the at-risk population)
