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  2. Hazard ratio - Wikipedia

    en.wikipedia.org/wiki/Hazard_ratio

    The hazard ratio is the effect on this hazard rate of a difference, such as group membership (for example, treatment or control, male or female), as estimated by regression models that treat the logarithm of the HR as a function of a baseline hazard () and a linear combination of explanatory variables:

  3. Proportional hazards model - Wikipedia

    en.wikipedia.org/wiki/Proportional_hazards_model

    For example, the hazard ratio of company 5 to company 2 is ⁡ (()) =. This means that, within the interval of study, company 5's risk of "death" is 0.33 ≈ 1/3 as large as company 2's risk of death. There are important caveats to mention about the interpretation:

  4. Failure rate - Wikipedia

    en.wikipedia.org/wiki/Failure_rate

    A concept closely-related but different [2] to instantaneous failure rate () is the hazard rate (or hazard function), (). In the many-system case, this is defined as the proportional failure rate of the systems still functioning at time t {\displaystyle t} (as opposed to f ( t ) {\displaystyle f(t)} , which is the expressed as a proportion of ...

  5. Accelerated failure time model - Wikipedia

    en.wikipedia.org/wiki/Accelerated_failure_time_model

    In full generality, the accelerated failure time model can be specified as [2] (|) = ()where denotes the joint effect of covariates, typically = ⁡ ([+ +]). (Specifying the regression coefficients with a negative sign implies that high values of the covariates increase the survival time, but this is merely a sign convention; without a negative sign, they increase the hazard.)

  6. Nelson–Aalen estimator - Wikipedia

    en.wikipedia.org/wiki/Nelson–Aalen_estimator

    The Nelson–Aalen estimator is a non-parametric estimator of the cumulative hazard rate function in case of censored data or incomplete data. [1] It is used in survival theory, reliability engineering and life insurance to estimate the cumulative number of expected events. An "event" can be the failure of a non-repairable component, the death ...

  7. Risk register - Wikipedia

    en.wikipedia.org/wiki/Risk_register

    A Risk register plots the impact of a given risk over of its probability. The presented example deals with some issues which can arise on a usual Saturday-night party.. A risk register is a document used as a risk management tool and to fulfill regulatory compliance acting as a repository [1] for all risks identified and includes additional information [1] about each risk, e.g., nature of the ...

  8. Risk matrix - Wikipedia

    en.wikipedia.org/wiki/Risk_matrix

    Risk is the lack of certainty about the outcome of making a particular choice. Statistically, the level of downside risk can be calculated as the product of the probability that harm occurs (e.g., that an accident happens) multiplied by the severity of that harm (i.e., the average amount of harm or more conservatively the maximum credible amount of harm).

  9. Safety engineering - Wikipedia

    en.wikipedia.org/wiki/Safety_engineering

    In addition, they typically formulate expectations regarding the creation and use of traceability in the project. For example, depending upon the criticality level of a requirement, the US Federal Aviation Administration guideline DO-178B/C requires traceability from requirements to design, and from requirements to source code and executable ...