A note on data monitoring, incomplete data and curtailed testing

Area of Science:

• Clinical Trial Methodology
• Statistical Inference in Medicine
• Biostatistics

Background:

• Fixed sample size clinical trials often face the question of early outcome determination.
• Curtailed testing approaches have been explored to address this uncertainty.
• Assessing the impact of missing data on significance testing is crucial.

Purpose of the Study:

• To introduce and define the concept of "probability of reversal" for statistical tests.
• To provide least upper bounds for the probability of reversal.
• To assess the relevance of this concept in determining early trial outcomes and handling missing data.

Main Methods:

• Theoretical statistical analysis.
• Development of the "probability of reversal" metric.
• Derivation of least upper bounds for this probability.

Main Results:

• The probability of reversal is defined as a measure related to early outcome determination.
• Associated least upper bounds are mathematically derived.
• The findings are applicable to assessing the impact of missing data in clinical trials.

Conclusions:

• The probability of reversal offers a novel perspective on curtailed testing in clinical trials.
• This metric can help ascertain if trial outcomes are definitive before complete data accrual.
• The results provide a framework for evaluating the significance of missing data.