Clinical Trial Laboratory Data Nested With in Subject: Components of Variance, Sample Size and Cost.

Area of Science:

• Statistical experimental design
• Biological and laboratory research
• Human bio-specimen analysis

Background:

• Nesting of experimental factors is common in agricultural, environmental, and engineering studies.
• It is less discussed in biological experiments using human bio-specimens.
• Sample size is often determined at the subject level, neglecting lower-level units.

Purpose of the Study:

• To revisit experimental nesting frameworks for biological studies.
• To discuss the coherent utilization of variability, sampling costs, and sample size at lower levels.
• To demonstrate how lower-level sampling decisions impact the number of subjects required.

Main Methods:

• Revisiting the experimental nesting framework.
• Analyzing variability and cost of sampling at different experimental levels.
• Illustrating with an example from spectroscopic microscopy and lung cancer research.

Main Results:

• Inadequate sampling at lower levels necessitates adjustments to the total number of subjects.
• Variability and cost at lower levels can be coherently utilized in experimental design.
• Provides guidance on determining sample sizes at all levels of a nested experimental design.

Conclusions:

• Experimental nesting requires careful consideration of all levels, not just the subject level.
• Optimizing lower-level sampling is essential for efficient and accurate biological research.
• This approach is vital for studies involving human bio-specimens and complex experimental designs.