The use and misuse of short cognitive tests in the diagnosis of dementia.

Short cognitive tests are widely used in medicine to assess patients with memory problems but their role in the assessment of patients with cognitive problems is often misunderstood. They are a part of the examination of the patient and not tests for dementia or 'case-finding tools'. This misunderstanding leads to widespread misconceptions concerning short cognitive tests and could lead to major over diagnosis or under diagnosis of dementia. Their use in clinical practice particularly in response to national directives aimed at increasing diagnosis rates in dementia needs a clear understanding of their role and limitations. A new classification of short cognitive tests is proposed with guidance on their use in clinical medicine.