Clinical Trials

■■❚❙❘Chapter 28RepeatedMeasurementsDuolao Wang and Zoe FoxIn many clinical trials, particularly pharmacokinetic andpharmacodynamic studies, an outcome or marker measurementis recorded at different time points for each subject, generatingrepeated measurement data, which are often correlated.Failure to take account of such correlation in the analysiscould produce biased estimates of true treatment effects.There are various strategies that can be used to analyze suchdata, depending on the questions you wish to answer and thetype of data you will be collecting. In this chapter, we presentan overview of the various strategies for dealing with repeatedmeasurements of a continuous outcome, and explore in moredetail the use of summary measures, which convert mutipledata points into a singular measure (eg, mean or area underthe curve).317