enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Odds ratio - Wikipedia

    en.wikipedia.org/wiki/Odds_ratio

    And an odds ratio less than 1 indicates that the condition or event is less likely to occur in the first group. The odds ratio must be nonnegative if it is defined. It is undefined if p 2 q 1 equals zero, i.e., if p 2 equals zero or q 1 equals zero.

  3. Diagnostic odds ratio - Wikipedia

    en.wikipedia.org/wiki/Diagnostic_odds_ratio

    The diagnostic odds ratio ranges from zero to infinity, although for useful tests it is greater than one, and higher diagnostic odds ratios are indicative of better test performance. [1] Diagnostic odds ratios less than one indicate that the test can be improved by simply inverting the outcome of the test – the test is in the wrong direction ...

  4. 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 ...

  5. Hazard ratio - Wikipedia

    en.wikipedia.org/wiki/Hazard_ratio

    Hazard ratios differ from relative risks (RRs) and odds ratios (ORs) in that RRs and ORs are cumulative over an entire study, using a defined endpoint, while HRs represent instantaneous risk over the study time period, or some subset thereof. Hazard ratios suffer somewhat less from selection bias with respect to the endpoints chosen and can ...

  6. Contingency table - Wikipedia

    en.wikipedia.org/wiki/Contingency_table

    Two events are independent if and only if the odds ratio is 1; if the odds ratio is greater than 1, the events are positively associated; if the odds ratio is less than 1, the events are negatively associated. The odds ratio has a simple expression in terms of probabilities; given the joint probability distribution:

  7. 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

  8. AOL Mail

    mail.aol.com

    Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!

  9. Case–control study - Wikipedia

    en.wikipedia.org/wiki/Case–control_study

    They require fewer resources but provide less evidence for causal inference than a randomized controlled trial. A case–control study is often used to produce an odds ratio. Some statistical methods make it possible to use a case–control study to also estimate relative risk, risk differences, and other quantities. [2]