Item response theory analysis of cognitive tests in people with dementia: a systematic review

BMC Psychiatry

Research Article

Sarah McGrory¹  John M Starr²  Susan D Shenkin³  Jason M Doherty⁴  Elizabeth J Austin⁴ 

[1] Alzheimer Scotland Dementia Research Centre, University of Edinburgh, 7 George Square, EH8 9JZ, Edinburgh, UK;Alzheimer Scotland Dementia Research Centre, University of Edinburgh, 7 George Square, EH8 9JZ, Edinburgh, UK;Geriatric Medicine, University of Edinburgh, Edinburgh, UK;Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK;Geriatric Medicine, University of Edinburgh, Edinburgh, UK;Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK;Psychology, University of Edinburgh, Edinburgh, UK;

关键词: Item response theory;    Dementia;    Psychometrics;    Cognition;    Alzheimer disease;    MMSE;    Systematic review;   

DOI  :  10.1186/1471-244X-14-47

 received in 2013-04-16, accepted in 2014-02-13,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundPerformance on psychometric tests is key to diagnosis and monitoring treatment of dementia. Results are often reported as a total score, but there is additional information in individual items of tests which vary in their difficulty and discriminatory value. Item difficulty refers to an ability level at which the probability of responding correctly is 50%. Discrimination is an index of how well an item can differentiate between patients of varying levels of severity. Item response theory (IRT) analysis can use this information to examine and refine measures of cognitive functioning. This systematic review aimed to identify all published literature which had applied IRT to instruments assessing global cognitive function in people with dementia.MethodsA systematic review was carried out across Medline, Embase, PsychInfo and CINHAL articles. Search terms relating to IRT and dementia were combined to find all IRT analyses of global functioning scales of dementia.ResultsOf 384 articles identified four studies met inclusion criteria including a total of 2,920 people with dementia from six centers in two countries. These studies used three cognitive tests (MMSE, ADAS-Cog, BIMCT) and three IRT methods (Item Characteristic Curve analysis, Samejima’s graded response model, the 2-Parameter Model). Memory items were most difficult. Naming the date in the MMSE and memory items, specifically word recall, of the ADAS-cog were most discriminatory.ConclusionsFour published studies were identified which used IRT on global cognitive tests in people with dementia. This technique increased the interpretative power of the cognitive scales, and could be used to provide clinicians with key items from a larger test battery which would have high predictive value. There is need for further studies using IRT in a wider range of tests involving people with dementia of different etiology and severity.

【 授权许可】

CC BY   
© McGrory et al.; licensee BioMed Central Ltd. 2014