Joint one-sided and two-sided simultaneous confidence intervals.

Area of Science:

• Clinical Trials Methodology
• Statistical Analysis
• Biostatistics

Background:

• Traditional clinical trial analysis often relies on two-sided hypothesis testing.
• Complex trial designs, including multiple treatment arms and varying test directions, pose analytical challenges.
• Existing multiple comparison procedures may lack flexibility for mixed one- and two-sided tests.

Purpose of the Study:

• To demonstrate the application of existing multiple comparison procedures to complex clinical trial designs.
• To introduce a flexible framework using contrast tests for analyzing trials with mixed one- and two-sided hypotheses.
• To compare the power and flexibility of proposed contrast tests against existing methods.

Main Methods:

• Application of established multiple comparison procedures for normally distributed means (difference and ratio).
• Development and implementation of contrast tests accommodating one- and two-sided hypothesis directions.
• Utilizing statistical software (R and SAS System) for practical illustration.

Main Results:

• Straightforward application of multiple comparison procedures is feasible for complex trial designs.
• Proposed contrast tests offer a more flexible analytical framework.
• The proposed methods achieve nearly similar statistical power compared to existing approaches.

Conclusions:

• Mixed one- and two-sided tests provide a preferred analytical approach for certain multiarmed clinical trials.
• Contrast tests offer enhanced flexibility for complex trial designs without compromising power.
• The presented methods and software codes facilitate advanced statistical analysis in clinical research.