Educational Toolbox

The value of a medical study, which we take to be any human health related investigation, depends primarily on the value of the question or questions…

Educational Toolbox

Study design

07-05-2021

The value of a medical study, which we take to be any human health related investigation, depends primarily on the value of the question or questions…

Educational Toolbox

Accuracy, Sensitivity and Specificity

04-05-2021

Sensitivity and specificity are one approach to quantifying the diagnostic ability of the test. In clinical practice, however, the test result is all…

Educational Toolbox

Statistical significance (p-value)

23-04-2021

The level of statistical significance is often expressed as a p-value between 0 and 1. The smaller the p-value, the stronger the evidence that you…

Educational Toolbox

Positive and negative predictive values

05-05-2021

Positive predictive value is the proportion of patients with positive test results who are correctly diagnosed. Negative predictive value is the…

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Effect size

04-05-2021

Researchers often seek to learn more than whether the variable under investigation has an effect and/or the direction of the effect. This is…

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RR, OR, HR

28-04-2021

Risk ratios, odds ratios, and hazard ratios are three common, but often misused, statistical measures in clinical research. Understanding the three…

Educational Toolbox

Confidence intervals

04-05-2021

A confidence interval is an interval which has a known and controlled probability (generally 95% or 99%) to contain the true value.

Educational Toolbox

Receiver operating characteristic (ROC)

04-05-2021

Receiver operating characteristic (ROC) analysis is a graphical approach for analyzing the performance of a classifier. It uses a pair of statistics –…

Educational Toolbox

Power and sample size

03-05-2021

Power and sample size estimations are measures of how many patients are needed in a study. Nearly all clinical studies entail studying a sample of…

Educational Toolbox

LoB, LoD and LoQ

04-05-2021

Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) are terms used to describe the smallest concentration of a measurand…