COSMIN methodology for evaluating the content validity of patient-reported outcome measures: a Delphi study

Area of Science:

• Health Measurement
• Psychometrics
• Clinical Epidemiology

Background:

• Content validity is crucial for patient-reported outcome measures (PROMs) but challenging to assess.
• Existing guidelines for assessing PROM content validity require updates and standardization.

Purpose of the Study:

• To develop standards for evaluating PROM development quality.
• To update COSMIN standards for content validity studies of PROMs.
• To define criteria for good PROM content validity and a rating system for systematic reviews.

Main Methods:

• A 4-round online Delphi study involving 159 international experts.
• Experts rated proposed standards and criteria using 5-point scales and provided arguments.
• Consensus was reached on all issues after four rounds, followed by pilot testing.

Main Results:

• Ten criteria for good content validity were defined, covering item relevance, response options, recall period, comprehensiveness, and comprehensibility.
• Consensus was achieved on all proposed standards, criteria, and rating issues.
• The methodology was refined through pilot testing.

Conclusions:

• The consensus-based COSMIN methodology provides a detailed, standardized, and transparent approach to content validity assessment.
• This updated methodology can improve the selection and utilization of high-quality PROMs in research and clinical settings.