Search results
Results from the WOW.Com Content Network
MDCalc is a free online medical reference for healthcare professionals that provides point-of-care clinical decision-support tools, including medical calculators, scoring systems, and algorithms. [1] MDCalc is also a mobile and web app. [ 2 ] The decision-support tools are based on published clinical research, [ 3 ] and MDCalc’s content is ...
In null-hypothesis significance testing, the p-value [note 1] is the probability of obtaining test results at least as extreme as the result actually observed, under the assumption that the null hypothesis is correct. [2] [3] A very small p-value means that such an extreme observed outcome would be very unlikely under the null hypothesis.
The first DOS version of MedCalc was released in April 1993 and the first version for Windows was available in November 1996. Version 15.2 introduced a user-interface in English, Chinese (simplified and traditional), French, German, Italian, Japanese, Korean, Polish, Portuguese (Brazilian), Russian and Spanish.
For a 2-tailed test, multiply that number by two to obtain the p-value. If the p-value is below a given significance level, one rejects the null hypothesis (at that significance level) that the quantities are statistically independent. Numerous adjustments should be added to when accounting for ties.
The Nottingham prognostic index (NPI) is used to determine prognosis following surgery for breast cancer. [1] [2] Its value is calculated using three pathological criteria: the size of the tumour; the number of involved lymph nodes; and the grade of the tumour. [1]
Statistical tests, charts, probabilities, and clear results. Automatically checks assumptions, interprets results, and outputs graphs, histograms, and charts. Online statistics calculators support the test statistic and the p-value and more results like effect size, test power, and normality level.
The Bonferroni correction can also be applied as a p-value adjustment: Using that approach, instead of adjusting the alpha level, each p-value is multiplied by the number of tests (with adjusted p-values that exceed 1 then being reduced to 1), and the alpha level is left unchanged.
Another disadvantage is that investigators and readers frequently do not understand how the p-values are reported: for example, if there are five interim analyses planned, but the trial is stopped after the third interim analysis because the p-value was 0.01, then the overall p-value for the trial is still reported as <0.05 and not as 0.01. [4]