Use of Patient and Investigator Global Impression Scales: A Review of Food and Drug Administration–Approved Labeling, 2009 to 2019

Identify disease categories in which single-item global impression (GI) scales were included in product labeling of new drugs approved by the US Food and Drug Administration (FDA) in January 2009-December 2019 and review the characteristics of GIs included in product labeling of new FDA-approved drugs (January 2017-December 2019). FDA Clinical Outcome Assessment (COA) Compendium was reviewed for drug labels that included GIs for drugs approved in 2009-2016. The indication, year of approval, ICD-10 code, and GI respondent were noted. A manual review of labels of FDA-approved drugs (2017-2019) was undertaken to identify GIs included in the labels. Corresponding drug approval packages were reviewed to identify details of any regulatory reviewer comments related to GIs. GI characteristics were noted from the drug label or the review documents, including the respondent, type of measure (static or dynamic), item wording, concept assessed, and response options. Product labeling containing GIs was most common in diseases related to the skin, nervous system, behavioral disorders, and the musculoskeletal system. GIs were included in 30/77 (39.0%) drug labels in the four disease categories. In the past 10 years, GIs have been included as endpoint measures in confirmatory clinical trials and have generated evidence of treatment benefit in diseases related to the skin, nervous system, behavioral disorders, and the musculoskeletal system. GIs frequently provide important insights into the patient experience. Before GIs are included in clinical trials to assess treatment benefit, it is important to ensure that they are valid, reliable, and responsive.