Table 1.

Taxonomy of PROs Used in Clinical Trials

Attribute	Types
Intended use of the measure	• To define entry criteria for study populations • To evaluate efficacy • To evaluate adverse events
Concepts measured	• Overall health status • Symptoms/signs, individually or as a syndrome associated with a medical condition • Functional status (physical, psychological or social) • Health perceptions (e.g., self-rating of health or worry about condition) • Satisfaction with treatment or preference for treatment • Adherence to medical treatment
Number of items	• Single item for single concept • Multiple items for single concept • Multiple items for multiple domains within a concept
Intended measurement population or condition	• Generic • Condition-specific • Population-specific
Mode of data collection	• Interviewer-administered • Self-administered, with or without supervision • Computer-administered or computer-assisted • Interactively administered (e.g., interactive voice response systems or Web-based systems)
Timing and frequency of administration	• As events occur • At regular intervals throughout a study • Baseline and end of treatment
Types of scores	• Single rating on a single concept (e.g., pain severity) • Index – single score combining multiple ratings of related domains or independent concepts • Profile – multiple uncombined scores of multiple-related domains • Battery – multiple uncombined scores of independent concepts • Composite – an index, profile, or battery
Weighting of items or concepts	• All items and domains are equally weighted • Items are assigned variable weights • Domains are assigned variable weights
Response options	• See Table 2 for examples of response options (types of PRO scales)