[Prognostic factor identified… Now what? What we can and cannot learn from prognostic factor research]

Area of Science:

• Medical Research Methodology
• Epidemiology
• Biostatistics

Background:

• Statistical associations between factors and outcomes are often misinterpreted as causal.
• The distinction between associative and causal relationships in prognostic factor research can be unclear.
• Overestimation of evidence from prognostic factor studies is common.

Purpose of the Study:

• To provide guidance on interpreting findings from prognostic factor research.
• To highlight the limitations of prognostic factor studies in establishing causality.
• To advise on the appropriate application of prognostic factor research in clinical practice.

Main Methods:

• Review and synthesis of principles for interpreting prognostic factor research.
• Emphasis on critical assessment of study purpose, design, and statistical analysis.
• Discussion of the potential for misattribution of causal or predictive qualities.

Main Results:

• Prognostic factor research findings are often overestimated, particularly when using multivariable analysis.
• Attributing causal or predictive qualities to prognostic factors based solely on association is scientifically unsound.
• Direct applicability of prognostic factor research in daily medical practice is frequently limited.

Conclusions:

• Refrain from making causal or predictive judgments solely based on prognostic factor studies.
• Prognostic factor research serves as a valuable starting point for further investigation.
• Critical evaluation of study methodology is essential for accurate interpretation and application.