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STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT
Measuring agreement in method comparison studies
The 95% limits of agreement, estimated by mean difference 1.96 standard deviation of the differences, provide an interval within which 95% of differences between measurements by the two methods are expected to lie.
Statistics notes: Cronbach's alpha
Many quantities of interest in medicine, such as anxiety or degree of handicap, are impossible to measure explicitly. Instead, we ask a series of questions and combine the answers into a single…
Measurement in Medicine: The Analysis of Method Comparison Studies
This paper shall describe what is usually done, show why this is inappropriate, suggest a better approach, and ask why such studies are done so badly.
Multiple significance tests: the Bonferroni method
A simulation of a clinical trial of the treatment of coronary artery disease by allocating 1073 patient records from past cases into two “treatment” groups at random failed to show any significant difference in survival between those patients allocated to the two treatments.
Almost all studies have some missing observations, and textbooks and software commonly assume that data are complete, and the topic of how to handle missing data is not often discussed outside statistics journals.
Agreement Between Methods of Measurement with Multiple Observations Per Individual
Methods for analysing clustered observations, both when the underlying quantity is assumed to be changing and when it is not, are described.
Statistics Notes: Diagnostic tests 2: predictive values
Using the same data as in the previous note,1 the authors know that 231 of 263 patients with abnormal liver scans had abnormal pathology, giving the proportion of correct diagnoses as 231/263 = 0.88.