Cognitive assessment in the elderly: a review of clinical methods

Doctors are poor at predicting patients’ cognitive function based on a routine, non-cognitive evaluation alone. 1, , 2 Cognitive assessment is a valuable clinical skill. It facilitates the diagnosis of disorders that impair thinking, and allows for more accurate estimates of functional ability to be made. Cognition also predicts mortality during hospital admissions. 3 These benefits are clearly of practical value, and cognitive assessment may also be a skill that could be used in the Directly Observed Procedural Skills (DOPS) framework for on-going evaluation of training geriatricians and neurologists. As people age, changes occur within the brain that lead to differences in thinking and behaviour. 4 Distinguishing these from the early stages of an abnormal (disease) process is fairly arbitrary; definitions usually depend upon an impact on social, functional or occupational activities. To further cloud the picture, there is a diagnosis of ‘cognitive impairment not dementia’ (CIND) also available to the clinician, which sits somewhere between normal ageing and dementia. Dementia rises in prevalence from 65 years, and to ∼33% of those aged >85 years. 5–8 CIND is even more common, with an estimated prevalence of around 17% in people aged >65 years. 9 Of course, changes in cognition are not specific to either CIND or dementia: other common causes in the elderly include delirium and depression. Two or more of these are frequently found within a single patient. Other, psychiatric (or ‘non-organic’), cognitive disorders (e. g. schizophrenia) are beyond the scope of this text. Cognitive assessment is commonly used for the following reasons: (i) screening for cognitive impairment; (ii) differential diagnosis of cause; (iii) rating of severity of disorder, or monitoring disease progression. These three factors form the basis of the structure of this review. A wide … Address correspondence to Dr H. Woodford, Department of Medicine for the Elderly, Cumberland Infirmary, Carlisle CA2 7HY. email: henry. woodfordatncumbria-acute. nhs. uk