Validity, reliability, and feasibility of clinical staging scales in dementia: a systematic review.

New staging systems of dementia require adaptation of disease management programs and adequate staging instruments. Therefore, we systematically reviewed the literature on validity and reliability of clinically applicable, multidomain, and dementia staging instruments. A total of 23 articles describing 12 staging instruments were identified (N = 6109 participants, age 65-87). Reliability was studied in most (91%) of the articles and was judged moderate to good. Approximately 78% of the articles evaluated concurrent validity, which was good to very good, while discriminant validity was assessed in only 25%. The scales can be applied in ±15 minutes. Clinical Dementia Rating (CDR), Global Deterioration scale (GDS), and Functional Assessment Staging (FAST) have been monitored on reliability and validity, and the CDR currently is the best-evidenced scale, also studied in international perspective, and is available in 14 languages. Taking into account the increasing differentiation of Alzheimer's disease in preclinical and predementia stages, there is an urgent need for global rating scales to be refined as well.