Hazard Ratio

The hazard ratio in survival analysis is the effect of an explanatory variable on the hazard or risk of an event. For a less technical definition than is provided here, consider hazard ratio to be an estimate of relative risk and see the explanation on that page.The instantaneous hazard rate is the limit of the number of events per unit time divided by the number at risk as the time interval decreases. where N(t) is the number at risk at the beginning of an interval.
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A term used to compare an animal's daily dietary intake of a pesticide to its LD 50 value. A ratio greater than 1.0 indicates that the animal is likely to consume an a dose amount which would kill 50 percent of animals of the same species. (See: LD 50 /Lethal Dose.)