![]() ![]() The reliability of a measurement is an important consideration in the choice of the primary outcome measure for a clinical trial and in the choice of measures used for assessment of eligibility and exclusion. All decline as the reliability of the measure declines. The reliability of a measurement determines its maximal correlation or R2 and slope (or effect size) in regression models, its sensitivity and specificity when used for classifications or predictions, and the power of a statistical test employing the measurement. The coefficient of reliability is an estimate of the proportion of all variation that is not due to measurement error and is readily estimated from replicate measurements. ![]() Reliability is often confused with validity, which refers to the extent to which the variable properly measures the underlying trait of interest. Reliability refers to the reproducibility of the measurement when repeated at random in the same subject or specimen. One of the principal characteristics of an outcome measure in a clinical trial, and any measurement in general, is its reliability.
0 Comments
Leave a Reply. |