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Mansa Musa was the ruler of the Mali Empire in West Africa. Details recorded here should be sourced; unknown information is left blank.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
In epidemiology, the relative risk reduction (RRR) or efficacy is the relative decrease in the risk of an adverse event in the exposed group compared to an unexposed group. It is computed as , where is the incidence in the exposed group, and is the incidence in the unexposed group. If the risk of an adverse event is increased by the exposure rather than decreased, the term relative risk increase (RRI) is used, and it is computed as .[1][2] If the direction of risk change is not assumed, the term relative effect is used, and it is computed in the same way as relative risk increase.[3]
| Quantity | Experimental group (E) | Control group (C) | Total |
|---|---|---|---|
| Events (E) | EE = 15 | CE = 100 | 115 |
| Non-events (N) | EN = 135 | CN = 150 | 285 |
| Total subjects (S) | ES = EE + EN = 150 | CS = CE + CN = 250 | 400 |
| Event rate (ER) | EER = EE / ES = 0.1, or 10% | CER = CE / CS = 0.4, or 40% | — |
| Variable | Abbr. | Formula | Value |
|---|---|---|---|
| Absolute risk reduction | ARR | CER − EER | 0.3, or 30% |
| Number needed to treat | NNT | 1 / (CER − EER) | 3.33 |
| Relative risk (risk ratio) | RR | EER / CER | 0.25 |
| Relative risk reduction | RRR | (CER − EER) / CER, or 1 − RR | 0.75, or 75% |
| Preventable fraction among the unexposed | PFu | (CER − EER) / CER | 0.75 |
| Odds ratio | OR | (EE / EN) / (CE / CN) | 0.167 |
| Quantity | Experimental group (E) | Control group (C) | Total |
|---|---|---|---|
| Events (E) | EE = 75 | CE = 100 | 175 |
| Non-events (N) | EN = 75 | CN = 150 | 225 |
| Total subjects (S) | ES = EE + EN = 150 | CS = CE + CN = 250 | 400 |
| Event rate (ER) | EER = EE / ES = 0.5, or 50% | CER = CE / CS = 0.4, or 40% | — |
| Variable | Abbr. | Formula | Value |
|---|---|---|---|
| Absolute risk increase | ARI | EER − CER | 0.1, or 10% |
| Number needed to harm | NNH | 1 / (EER − CER) | 10 |
| Relative risk (risk ratio) | RR | EER / CER | 1.25 |
| Relative risk increase | RRI | (EER − CER) / CER, or RR − 1 | 0.25, or 25% |
| Attributable fraction among the exposed | AFe | (EER − CER) / EER | 0.2 |
| Odds ratio | OR | (EE / EN) / (CE / CN) | 1.5 |
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Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
In epidemiology, the relative risk reduction (RRR) or efficacy is the relative decrease in the risk of an adverse event in the exposed group compared to an unexposed group. It is computed as ( I u − I e ) / I u {\displaystyle (I_{u}-I_{e})/I_{u}} , where I e {\displaystyle I_{e}} is the incidence in the exposed group, and I u {\displaystyle I_{u}} is the incidence in the unexposed group. If the risk of an adverse event is increased by the exposure rather than decreased, the term relative risk increase (RRI) is used, and it is computed as ( I e − I u ) / I u {\displaystyle (I_{e}-I_{u})/I_{u}} . If the direction of risk change is not assumed, the term relative effect is used, and it is computed in the same way as relative risk increase.
Risk reduction may refer to: Health Absolute risk reduction or relative risk reduction, statistical descriptors of an intervention. Harm reduction, in public health General Risk management Disaster risk reduction Safety integrity level Finance Hedge (finance) Diversification (finance)
In epidemiology and biostatistics, the experimental event rate (EER) is a measure of how often a particular statistical event (such as response to a drug, adverse event or death) occurs within the experimental group (non-control group) of an experiment. This value is very useful in determining the therapeutic benefit or risk to patients in experimental groups, in comparison to patients in placebo or traditionally treated control groups. Three statistical terms rely on EER for their calculation: absolute risk reduction, relative risk reduction and number needed to treat.
In epidemiology, preventable fraction among the unexposed (PFu) is the proportion of incidents in the unexposed group that could be prevented by exposure. It is calculated as P F u = ( I u − I e ) / I u = 1 − R R {\displaystyle PF_{u}=(I_{u}-I_{e})/I_{u}=1-RR} , where I e {\displaystyle I_{e}} is the incidence in the exposed group, I u {\displaystyle I_{u}} is the incidence in the unexposed group, and R R {\displaystyle RR} is the relative risk. It is a synonym of the relative risk reduction. It is used when an exposure reduces the risk, as opposed to increasing it, in which case its symmetrical notion is attributable fraction among the exposed.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Shirley Chisholm, elected in 1968.
