What is the PGI-I scale?

• A. Patient Global Impression of Improvement; a patient-reported measure of perceived improvement.
• B. Physician Global Impression of Improvement; clinician-rated.
• C. Patient Global Impact Index.
• D. Procedural Global Instrument.

Answer: (A)

Patient Global Impression of Improvement is a patient-reported measure of perceived change since starting treatment. It captures the patient’s own view of how much they have improved (or worsened) and is usually a single item on a 7-point scale, from very much improved to very much worse. This makes it distinct from clinician-rated scales, since it relies on the patient’s personal perception of change. The other options describe either a clinician’s rating or are not standard terms, so they don’t fit the standard meaning of PGI-I.