Global Assessment Variables measure what in a clinical trial?

• A. The global assessment measures the overall safety, efficacy, and/or usefulness of a treatment, integrating objective data and the investigator’s overall impression.
• B. A simple numerical endpoint such as a single lab value.
• C. A scale of ordered categorical ratings reflecting the investigator’s general impression.
• D. The rate of adverse events per patient-year.

Answer: (C)

Global Assessment Variables are about capturing the investigator’s overall impression of a patient’s status or treatment effect on an ordered, categorical scale. This means data come from a subjective global rating, not a single measurement or a count of events. The scales are typically ordinal, with categories arranged from more favorable to less favorable (for example, markedly improved to very much worse), reflecting the clinician’s general view of improvement or change. Because the data are ordinal, analyses rely on nonparametric approaches and don’t assume equal spacing between categories. This is why the best description is a scale of ordered categorical ratings reflecting the investigator’s general impression. It isn’t a lone lab value, it isn’t a rate of adverse events, and it isn’t merely a broad combination of objective data with impression.