Definitions for

**"Relative risk"****Related Terms:**Attributable risk, Risk ratio, Odds ratio, Absolute risk, Confounder, Uncertainty factor, Risk factor, Uncertainty, Risk exposure, Absolute risk reduction, Relative risk reduction, Risk , Negative predictive value, Case-control study, Risk factors, Confounding, Likelihood ratio, Confounding factors, Likelihood, Statistical significance, Uncertainty, Prognosis, Minimal risk, High risk, Statistically significant, Bayes' theorem, Probability, Acceptable risk, Cohort study, Confounding factor, Significant, Rrr, Probability theory, Prevalence rate, Risk matrix, Antiselection, Risk assessment, P-value, P value, Significance, Theoretical probability, Probabilistic risk assessment, Conditional probability, Risk characterization, Law of large numbers, Probability distribution, Baseline risk assessment, Risk reduction, Score, Confidence level

The ratio of the rate of the disease (usually incidence or mortality) among those exposed to the rate among those not exposed.

The risk that someone incurs relative to a population standard; e.g., the risk of developing a cardiovascular disease with a diastolic blood pressure of 90 mmHg when compared to a diastolic blood pressure less than 90 mmHg.

The ratio of disease incidence (or mortaility) in an exposed population to that in an unexposed population.

The ratio of the probability of a condition or disease in an exposed population to the probability of the same condition or disease in a nonexposed population.

The chance of having something or being affected by something compared with people in a comparable situation. Usually given as a ratio, a proportion or a percentage as in the chance of having endometriosis; if your sister has it, you have a relative risk of 7:1 -- or seven times the risk -- compared with the general population of women of the same age; your relative risk of developing cancer of the ovaries if you've accumulated 10 years on the oral contraceptive pill is 1:5, 0.2 or 20.

The ratio of health impact incidence among exposed individuals to incidence among unexposed individuals.

A measure of the risk of disease in an exposed group compared with the risk of an unexposed group. A relative risk of 1.0 means that risks in the two groups are the same. For example, if risk is double for an exposed population, the relative risk is 2.0.

The excess incidence or prevalence of the disease in people with the risk factor compared with people without the risk factor. This is used in cohort studies where those with and without the risk factor are followed to observe which individuals become diseased.

An expression of excess risk relative to the underlying (baseline) risk; if the excess equals the baseline risk the relative risk is 2.

Relative risk (RR) could, and perhaps should, have been termed “relative probability.” It is the ratio of the probability of an event under one condition (or group) to the probability under another condition. RR is interpretable as a comparative quantity; the RR comparing Group A with an event probability of .6 to Group B with a probability of .3 is 2.0. The same RR would result if the probabilities were ten times smaller (i.e., .06 to .03). In both comparisons, the RR indicates that the event is twice more likely to occur in Group A than Group B. Depending on the choice of the event, RR could be a “risk” if the event is untoward, cancer say, or it could be a “benefit” if the event was desired, not getting cancer.

The chances of contracting a disease from a particular cause (e.g., alcohol use) relative to the chances of contracting a disease in general. For example, if the relative risk of falls related to alcohol 3, it means that people using alcohol are 3 times more likely to be injured in a fall than people who do not use alcohol.

The ratio of the incidence of a disease among those exposed to the the incidence among those not exposed.

Ratio of the risk of disease or death among the exposed segment of the population to the risk among the unexposed.

A ratio obtained by dividing the incidence rate of one group by the incidence of another group. If the rates are equal, the resulting relative risk is one.

a comparison between two risks

(also called risk ratio.) The probability of occurrence of a disease in the presence of a putative causal agent divided by the probability of occurrence in the absence of the agent.

The risk of a health event occurring in the presence of a risk factor (or use of a drug), as compared to the risk of an event occurring in the absence of that risk factor or drug.

the ratio between the risk for disease in an irradiated population to the risk in an unexposed population. A relative risk of 1.1 indicates a 10% increase in cancer from radiation, compared with the "normal" incidence. See also risk, absolute risk.

comparison of the risk between exposed and unexposed persons. A relative risk of 1 means there is no difference. A relative risk of 10 means the outcome is 10 times more common among exposed people. A relative risk of 1/10 means the outcome is 10 times more frequent in unexposed people (the exposure is a protective factor).

How the result of an epidemiological study is often expressed. The ratio of the risk in the exposed group to the risk in the non-exposed group. An relative risk of 1 means there is no association between exposure and disease. Relative risk greater than 1 means the exposure is associated with the disease.

(RR): the ratio of the probability of developing, in a specified period of time, an outcome among those receiving the treatment of interest or exposed to a risk factor, compared with the probability of developing the outcome if the risk factor or intervention is not present. ( Therapy, Harm) To Calculation

The ratio of the incidence rate of a disease among individuals exposed to a specific risk factor to the incidence rate among unexposed individuals; synonymous with risk ratio. Alternatively, the ratio of the cumulative incidence rate in the exposed to the cumulative incidence rate in the unexposed (cumulative incidence ratio). The term relative risk has also been used synonymously with odds ratio. This is because the odds ratio and relative risk approach each other if the disease is rare ( 5 percent of population) and the number of subjects is large.

A comparison of the risk of some health-related event such as disease or death in two groups.

the ratio of disease incidence in the treated population divided by the incidence in an untreated (control) population.

A measurement of risk for which 1 represents normal. RR less than 1 suggests no risk. RR greater than 1 indicates some level of risk. Only an RR of greater than 2 is generally considered to be relevant to real human risk

The ratio between the number of cancer cases in the irradiated population to the number of cases expected in the unexposed population. A relative risk of 1.1 indicates a 10 percent increase in cancer due to radiation, compared to the "normal" incidence.

describes how the risk of a disease occurring among exposed people (e.g. people who smoke) compares with unexposed people. Also known as risk ratio.

a measure of comparative risk of developing a disease or condition. Statistically, RR is the chance that a person receiving an exposure will develop a condition compared to the chance that a non-exposed person will develop the same condition.

Relative risk (RR) or Risk ratio, is the ratio of the risk of the outcome of interest in the treated group (EER) to the risk in the control group (CER). It is typically used in randomised trials and cohort studies.

The chance of an observation occurring in association with a set of individuals compared to another set.

A measure of risk of disease in one group compared with another group. A relative risk of 1 means there is no increased risk in the group exposed to a suspected disease cause compared with those without this exposure. A relative risk higher than 1 means the risk is increased in the exposed group, while a relative risk lower than 1 implies the exposed group has a lower risk.

Puts the chance in comparative terms by describing the outcome rate for people exposed to the factor in question compared with the outcome rate for people not exposed to the factor. Although relative risks are the most commonly used measure of morbidity or mortality in the current medical literature, in most cases absolute risk is more relevant for the public.

A measure of the proportionate increase in disease rates among people exposed to a particular health risk factor compared with those not exposed to the factor; for example, the relative risk smokers have of developing lung cancer compared with non-smokers. Relative risk is expressed as the ratio of the incidence rate of those exposed to a factor to the incidence rate of those not exposed.

Statistics: Relative risk is the number of times more likely or less likely an event is in one set than another. It is the ratio of the absolute risk for each set. It is the same as an odds ratio in cases where events are rare. See: Absolute Risk

(Syn: risk ratio) A ratio of the risk of some health-related event such as disease or death among the exposed group to the risk among the unexposed group. This measure is usually used in cohort studies, and sometimes in cross-sectional studies. It is sometimes used as a synonym for "odds ratio" or "incidence rate ratio" if the disease is "rare" (i.e., incidence rate 10%).

Also called the 'risk ratio'. It is a common way of estimating the risk of experiencing a particular effect or result. A RR l means a person is estimated to be at an increased risk, while a RR 1 means a person is apparently at decreased risk. A RR of 1.0 means there is no apparent effect on risk at all. eg If the RR=4.0, the result is about 4 times as likely to happen, and 0.4 means it is 4 times less likely to happen. (See also confidence interval, odds ratio).

The relative risk of death for group A relative to group B is the ratio of the mortality risks. Strictly this refers to the ratio of the mortality rates (m), but it is approximately equal to the ratio of the mortality probabilities (q).

It is the risk "related" to an exposure, characteristic, or habit compared to the risk existing in those without the exposure, characteristic, or habit. It is a measure of the strength of the association of a risk factor or exposure with the disease.

proportion of patients experiencing an outcome in the treated (or exposed) group divided by the proportion experiencing the outcome in the control (or unexposed) group.

risk of adverse effects with a treatment relative to risk for those who do not receive treatment.

a relative risk (r.r.) quantifies how many times more or less likely the disease is in"exposed"people compared to "unexposed" people. Traditionally, exposure has been considered in terms of environmental agents; but in genetic studies, exposure can represent the underlying genotype or allele. A null value of 1.0 indicates that the disease is equally likely in exposed and unexposed people; a value greater than 1.0 indicates that the disease is more likely in the exposed people; and a value less than 1.0 suggests that the disease is more likely in the unexposed people. The relative risk is calculated from prospective data only. [Source: NHBLI/NCBI Glossary

(compare with absolute risk difference and odds ratio) The ratio of the risk (rate) of an outcome in the exposed group (eg to therapy involving the proposed drug) to the risk (rate) of the outcome in the control group in a specified time period.

The ratio of the incidence of a given disease in exposed or at risk persons to the incidence of the disease in unexposed persons. It is calculated in cohort or prospective studies. Relative Risk Reduction (RRR) proportional reduction in adverse-event rates between experimental and control groups in a trial.

The ratio of the risk of disease in persons exposed to a risk factor compared to the risk of disease in persons not exposed to the risk factor.

The relative measure of the difference in risk between the exposed and unexposed populations in a cohort study. The relative risk is defined as the rate of disease among the exposed divided by the rate of the disease among the unexposed. A relative risk of 2 means that the exposed group has twice the disease risk as the unexposed group.

For instance, the ratio of the risk of disease in one group compared to another group.

the risk of dying, or developing a disease (such as diabetes), over a period of time in a defined population (such as obese people) compared with the risk of dying or developing the same disease in a comparable population that does not possess the same risk (such as normal-weight people).

In statistics and mathematical epidemiology, relative risk (RR) is the risk of an event (or of developing a disease) relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus the control (non-exposed) group.