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  2. Hazard ratio - Wikipedia

    en.wikipedia.org/wiki/Hazard_ratio

    While the median endpoint ratio is a relative speed measure, the hazard ratio is not. [3] The relationship between treatment effect and the hazard ratio is given as . A statistically important, but practically insignificant effect can produce a large hazard ratio, e.g. a treatment increasing the number of one-year survivors in a population from ...

  3. Relative risk - Wikipedia

    en.wikipedia.org/wiki/Relative_risk

    In practice the odds ratio is commonly used for case-control studies, as the relative risk cannot be estimated. [1] In fact, the odds ratio has much more common use in statistics, since logistic regression, often associated with clinical trials, works with the log of the odds ratio, not relative risk. Because the (natural log of the) odds of a ...

  4. Number needed to harm - Wikipedia

    en.wikipedia.org/wiki/Number_needed_to_harm

    It is defined as the inverse of the absolute risk increase, and computed as / (), where is the incidence in the treated (exposed) group, and is the incidence in the control (unexposed) group. [1] Intuitively, the lower the number needed to harm, the worse the risk factor, with 1 meaning that every exposed person is harmed.

  5. Odds ratio - Wikipedia

    en.wikipedia.org/wiki/Odds_ratio

    An odds ratio (OR) is a statistic that quantifies the strength of the association between two events, A and B. The odds ratio is defined as the ratio of the odds of event A taking place in the presence of B, and the odds of A in the absence of B. Due to symmetry, odds ratio reciprocally calculates the ratio of the odds of B occurring in the presence of A, and the odds of B in the absence of A.

  6. Rare disease assumption - Wikipedia

    en.wikipedia.org/wiki/Rare_disease_assumption

    and = / / = While the prevalence is only 9% (9/100), the odds ratio (OR) is equal to 11.3 and the relative risk (RR) is equal to 7.2. Despite fulfilling the rare disease assumption overall, the OR and RR can hardly be considered to be approximately the same. However, the prevalence in the exposed group is 40%, which means is not sufficiently small

  7. Preventable fraction among the unexposed - Wikipedia

    en.wikipedia.org/wiki/Preventable_fraction_among...

    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 = / =, where is the incidence in the exposed group, is the incidence in the unexposed group, and is the relative risk.

  8. Proportional hazards model - Wikipedia

    en.wikipedia.org/wiki/Proportional_hazards_model

    Likewise, the risk of death (comparable to the speed of a bike) in hospital A is 8.3 times higher (faster) than the risk of death in hospital B (the reference group). the inverse quantity, / = ⁡ = ⁡ = is the hazard ratio of hospital B relative to hospital A.

  9. Attributable fraction for the population - Wikipedia

    en.wikipedia.org/wiki/Attributable_fraction_for...

    Attributable fraction for the population combines both the relative risk of an incident with respect to the factor, as well as the prevalence of the factor in the population. Values of AF p close to 1 indicate that both the relative risk is high, and that the risk factor is prevalent. In such case, removal of the risk factor will greatly reduce ...