About the Patient's Global Impression of Improvement (PGI-I)
The Patient's Global Impression of Improvement (PGI-I) is a validated, single-item patient-reported outcome measure that assesses a patient's perception of change in their condition following treatment. The questionnaire asks patients to rate their overall status since the start of treatment on a 7-point scale, ranging from "Very much improved" (1) to "Very much worse" (7). The PGI-I is widely used across multiple medical specialties, including urology, gynecology, psychiatry, and general medicine, to evaluate treatment effectiveness from the patient's perspective. Its simplicity and ease of administration make it a valuable tool in both clinical practice and research settings. The PGI-I has been validated in various patient populations and is commonly used as a responder criterion in clinical trials, where responses of "much improved" or "very much improved" are often considered clinically meaningful improvements.
Medical Specialties
Clinical Indications
Developer Information
The Patient's Global Impression of Improvement (PGI-I) is a widely used patient-reported outcome measure that has been adapted from the Clinical Global Impression (CGI) scales. While the exact origin of the PGI-I is not attributed to a single developer, it has been validated and used extensively across multiple medical specialties, including urology, gynecology, and psychiatry. The PGI-I is part of a family of global impression scales that assess patient and clinician perspectives on treatment outcomes.
Copyright & Licensing
The PGI-I is a public domain instrument and is freely available for use in clinical practice and research. No copyright restrictions apply. The PGI-I has been used extensively in clinical trials and research studies without licensing requirements.
Administration Instructions
Please rate your overall status since the start of treatment by selecting the option that best describes your condition. Consider how you feel now compared to when you started treatment.
Scoring Methodology
The PGI-I is a single-item questionnaire scored on a 7-point Likert scale. Response options are: 1. Very much improved (best outcome), 2. Much improved, 3. A little improved, 4. No change, 5. A little worse, 6. Much worse, 7. Very much worse (worst outcome). Since this is a single-item questionnaire, the score equals the raw value selected by the patient (1-7). Lower scores indicate better improvement, with scores of 1-2 typically considered clinically meaningful improvement. Scores of 6-7 indicate clinically significant deterioration. The PGI-I is often used as a responder criterion in clinical trials, where "much improved" or "very much improved" responses (scores of 1-2) are considered responders.
Meaningful Change Threshold
For the PGI-I, scores of 1-2 ("Very much improved" or "Much improved") are typically considered clinically meaningful improvement and are often used as responder criteria in clinical trials. A score of 3 ("A little improved") may represent minimal improvement, while scores of 4 ("No change") indicate no perceived change. Scores of 5-7 indicate deterioration, with scores of 6-7 representing clinically significant deterioration. The PGI-I is commonly used as a binary responder criterion, where patients with scores of 1-2 are classified as responders and all others as non-responders.
Score Interpretation
Understanding what your score means
very much improved
1Very much improved - Patient reports substantial improvement in their condition since the start of treatment. This represents the best possible outcome and is considered a clinically meaningful improvement.
much improved
2Much improved - Patient reports significant improvement in their condition since the start of treatment. This is considered a clinically meaningful improvement and is often used as a responder criterion in clinical trials.
a little improved
3A little improved - Patient reports minimal improvement in their condition since the start of treatment. This may represent a small but potentially meaningful change.
no change
4No change - Patient reports no perceived change in their condition since the start of treatment. The condition remains the same as at baseline.
a little worse
5A little worse - Patient reports minimal deterioration in their condition since the start of treatment. This may represent a small but potentially meaningful decline.
much worse
6Much worse - Patient reports significant deterioration in their condition since the start of treatment. This represents a clinically significant decline.
very much worse
7Very much worse - Patient reports substantial deterioration in their condition since the start of treatment. This represents the worst possible outcome and indicates a clinically significant decline.
Subscales
This questionnaire measures multiple dimensions
Clinical Limitations & Considerations
The PGI-I is a single-item measure that provides a global assessment of improvement but does not capture specific aspects of the condition or treatment effects. It relies on patient recall and subjective judgment, which may be influenced by factors such as expectations, mood, and external factors. The PGI-I does not provide information about the magnitude of change or specific domains affected. It should be used as part of a comprehensive clinical assessment rather than as the sole basis for treatment decisions. The PGI-I requires patients to have received treatment, which limits its applicability to baseline assessments. Cultural and language differences may affect interpretation, and validated translations should be used for non-English speaking populations.
Supporting Literature
Key validation and development studies for the Patient's Global Impression of Improvement (PGI-I)
- 1
Patient Global Impression of Improvement (PGI-I) as a measure of patient satisfaction after penile prosthesis implantation
Sadeghi-Nejad H, Sharma A, Irwin GM, Wilson SK, Delk JR
The Journal of Sexual Medicine, 2010
- 2
Validation of two global impression questionnaires for incontinence
Yalcin I, Bump RC
American Journal of Obstetrics and Gynecology, 2003
- 3
Validation of the Patient Global Impression of Improvement (PGI-I) for urogenital prolapse
Srikrishna S, Robinson D, Cardozo L
International Urogynecology Journal, 2010
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This questionnaire is provided free of charge. Patient Watch charges only for platform services (data storage, automated reminders, analytics) - not for use of clinical instruments. This non-commercial model supports academic and clinical use. View full licensing disclosure