Confirmatory clinical trials Safety data II

Safety monitoring in clinical studies can be both data and labor intensive. In the context of later-stage therapeutic exploratory and therapeutic confirmatory trials, the collection of laboratory data is no exception. Typically, participants in clinical trials provide blood or urine samples at every clinic visit. There is an expansive range of clinical chemistry tests that can be conducted using these samples. 

Samples may be analyzed by laboratories associated with each site (sometimes called local labs), each with its own handling procedures, assays, and reporting conventions, but this is not an optimal strategy. The use of a site s own laboratory poses no difficulties when the emphasis is on medical care, that is, the values obtained for a single individual. However, when conducting 

Differences from local lab to local lab may preclude a sponsor from meaningfully combining data from all participants across a number of Investigative sites. A statistical approach to standardizing laboratory values from a number of different labs (each potentially with their own reference ranges) has been described by Chuang-Stein (1992). However, standardization is time-consuming and the use of a number of local labs can introduce unwanted sources of variability that are neither easily quantified nor accounted for. 

In ICH Guidance E3 (1995), several analyses of clinical laboratory data are recommended. The approaches to describing clinical laboratory data include  

1 Measures of central tendency at each time point 

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Chapter 9 Confirmatory clinical trials Safety data II... 

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