CLINICAL GLOBAL MEASURES OF DEMENTIA - POSITION PAPER FROM THE INTERNATIONAL WORKING GROUP ON HARMONIZATION OF DEMENTIA DRUG GUIDELINES

Following is the report of the committee working on clinical global me asures for antidementia drug guidelines. The concepts involved in glob al scales, the distinctions between change and severity scales, advant ages and disadvantages of structured interviews, and anchoring of chan ge scores are discussed, and selected existing clinical global scales are described. In addition, the committee assessed the utility of glob al scales in clinical trials for antidementia drugs. There was a conse nsus among the members of the working group on the following: (1) Clin ical global scales are interview based; in most cases, they include in formation obtained from caregivers as well as directly from patients, but they can rely on information from the subject only. (2) Clinicians ' global ratings are intended to assess clinically meaningful change b ased on multidimensional clinical assessment and take into account the clinical heterogeneity of dementia by assessing at least cognition, b ehavior, and functioning. (3) There are two distinct types of clinical global measures: (a) clinicians' interview-based global severity scal es, which generally incorporate classification by stage or severity of illness and (b) clinicians' interview-based global change scales, whi ch incorporate global assessment ratings of clinical change. The commi ttee could not reach a consensus on whether global scales should be re quired in phase II and phase III clinical trials, or whether other spe cific assessments such as well-designed activities of daily living, co gnition, and behavior measures could, when used in appropriate combina tions, replace the global as assessments of clinical meaningfulness.