![]() More recently, Tsai and colleagues (2012) used the IRT to demonstrate that the levels of information that are provided by each of the MoCA's domains are consistent and that the language and executive functions domains provided the highest discrimination in the identification of MCI patients. Konsztowicz and colleagues (2011) developed a simplified adaptive approach to cognitive assessment (Geriatric Rapid Adaptive Cognitive Estimate, GRACE method), which reduces the test burden and allows for the evaluation of individuals across a broader range on the cognitive ability continuum, when compared with the MMSE and the MoCA. ![]() Afterwards, Koski and colleagues (2011) proposed an algorithm that combined items of the Mini Mental State Examination (MMSE Folstein, Folstein, & McHugh, 1975) and the MoCA in order to improve measurement precision for cognitive ability in milder forms of impairment. In this context, Koski and colleagues (2009) verified that the MoCA can provide a quantitative estimate of cognitive function, which allows for its use in monitoring changes in global cognition over time. The Rasch model is a psychometric method that is suitable for the analysis of neuropsychological assessment instruments ( Conrad & Smith, 2004 Prieto, Contador, Tapias-Merino, Mitchell, & Bermejo-Pareja, 2012 Prieto, Delgado, Perea, & Ladera, 2010). A few studies have examined the psychometric properties of the MoCA by using item response theory (IRT), namely the Rasch model ( Andrich, 1988 Rasch, 1960 Wright & Mok, 2004). In fact, the MoCA has been commonly used to measure global cognitive function in both clinical and research contexts. The MoCA's widespread international use and its recognition as one of the best screening tests ( Gauthier et al., 2011 Ismail, Rajji, & Shulman, 2010 Jacova, Kertesz, Blair, Fisk, & Feldman, 2007 Lonie, Tierney, & Ebmeier, 2009) is explained and supported by several previous studies that have consistently reported the good overall psychometric properties of MoCA and its improved sensitivity and usefulness in accurately identifying milder forms of cognitive impairment in many clinical conditions. Although it was initially designed for the global cognitive assessment of these patients, the MoCA is currently an extensively validated screening tool for many disorders, and it is translated into 36 languages and dialects (see studies in ). In response to the need for early identification of mild states of cognitive impairment among older people, particularly in the spectrum of Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD), Nasreddine and collaborators developed the Montreal Cognitive Assessment (MoCA Nasreddine et al., 2005) as a brief cognitive screening test. MoCA and its cognitive domains are suitable measures to use for screening the cognitive status of cognitively healthy subjects and patients with cognitive impairment.Īssessment, Aging, Mild Cognitive Impairment, Dementia Introduction ![]() ![]() The results show (i) an overall good fit for both the items and the persons’ values, (ii) high variability for the cognitive performance level of the cognitive domains (ranging between 1.90 and −3.35, where “Short-term Memory” was the most difficult item and “Spatial Orientation” was the easiest item) and between the subjects on the scale, (iii) high reliability for the estimation of the persons’ values, (iv) good discriminant validity and high diagnostic utility, and (v) a minimal differential item functioning effect related to of pathology, gender, age, and educational level. The study sample included 897 participants who were distributed into two main subgroups: (I) the clinical group (90 patients with Mild Cognitive Impairment, 90 patients with Alzheimer's disease, 33 patients with Frontotemporal Dementia, and 34 patients with Vascular dementia, whose diagnoses were previously established according to a consensus that was reached by a multidisciplinary team, based on the international criteria) and (II) the healthy group (composed of 650 cognitively healthy community dwellers). The psychometric properties of the Montreal Cognitive Assessment (MoCA) were examined by using the Partial Credit Model. ![]()
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