Table 1 Taxonomy of PROs Used in Clinical Trials

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)