The validity of health assessments: resolving some recent differences

Area of Science:

• Health Measurement
• Psychometrics
• Research Methodology

Background:

• Defining validity in health measures is crucial for accurate research.
• Existing frameworks for health test validity, such as longitudinal and cross-sectional construct validity, are debated.
• The distinction between a test's purpose and its measurement properties is a key point of contention.

Purpose of the Study:

• To critically examine the concept of validity in health measurement.
• To analyze different perspectives on classifying and validating health tests.
• To explore the relationship between the purpose of health tests and their measurement constructs.

Main Methods:

• Literature review of validity concepts in psychological and health measurement.
• Analysis of arguments by Guyatt et al. and Williams and Naylor regarding health test validity.
• Examination of evidence on how individuals make independent judgments about their health.

Main Results:

• The term "validity" is used idiosyncratically by different authors in health research.
• A test's use (content validity) should be distinguished from what it measures (construct validity).
• Cognitive health perceptions are sensitive to change in longitudinal designs, while emotional evaluations are less biased in cross-sectional designs.

Conclusions:

• Classifying health measures by their purpose may align with classifying them by their measurement constructs.
• The interactional model of health suggests multiple constructs, potentially linking test purpose and measurement.
• Understanding the nuances of health measurement validity is essential for appropriate research design and interpretation.