DECISION MAKING IN RESEARCH AND CLINICAL PRACTICE: Part II: The decision and its interpretation

Area of Science:

• Decision Science
• Research Methodology
• Physical Therapy

Background:

• Part I established foundational concepts of decision making and interpretation.
• This paper, Part II, builds upon those foundations.
• Effective research evaluation and design require understanding statistical principles.

Purpose of the Study:

• To elucidate decision rules and their role in the research process.
• To clarify the interpretation of statistical significance and decision errors.
• To equip clinical therapists with skills for critically appraising physical therapy research and improving study design.

Main Methods:

• Discussion of decision rules and their application in research.
• Explanation of statistical decision errors (Type I and Type II errors).
• Guidance on interpreting tests of significance and differentiating statistical from practical significance.

Main Results:

• Statistical significance indicates a low probability of observing results if the null hypothesis is true.
• Practical significance relates to the magnitude and clinical relevance of findings.
• Distinguishing between statistical and practical significance is crucial for clinical application.

Conclusions:

• Understanding decision errors and significance testing enhances research critique.
• Therapists can better evaluate the clinical importance of research findings.
• Improved comprehension facilitates the design and execution of robust clinical research projects.