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Screening and facilitating further assessment for cognitive impairment after stroke: application of a shortened Montreal Cognitive Assessment (miniMoCA) a
Nerissa Campbell , Danielle Rice , Lauren Friedman , Mark Speechley
& Robert W.
Lawson Health Research Institute, St. Joseph's Health Care, London, Ontario, Canada,
Department of Epidemiology & Biostatistics, Schulich Interfaculty Program in Public Health, Western University, London, Ontario, Canada,
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Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada,
Parkwood Hospital, St. Joseph's Health Care, London, Ontario, Canada, and
Department of Physical Medicine and Rehabilitation, Western University, London, Ontario, Canada Published online: 01 Jul 2015.
To cite this article: Nerissa Campbell, Danielle Rice, Lauren Friedman, Mark Speechley & Robert W. Teasell (2015): Screening and facilitating further assessment for cognitive impairment after stroke: application of a shortened Montreal Cognitive Assessment (miniMoCA), Disability and Rehabilitation To link to this article: http://dx.doi.org/10.3109/09638288.2015.1047968
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http://informahealthcare.com/dre ISSN 0963-8288 print/ISSN 1464-5165 online Disabil Rehabil, Early Online: 1–4 ! 2015 Informa UK Ltd. DOI: 10.3109/09638288.2015.1047968
Screening and facilitating further assessment for cognitive impairment after stroke: application of a shortened Montreal Cognitive Assessment (miniMoCA) Nerissa Campbell1, Danielle Rice1, Lauren Friedman1, Mark Speechley2,3, and Robert W. Teasell3,4,5
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Lawson Health Research Institute, St. Joseph’s Health Care, London, Ontario, Canada, 2Department of Epidemiology & Biostatistics, Schulich Interfaculty Program in Public Health, Western University, London, Ontario, Canada, 3Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada, 4Parkwood Hospital, St. Joseph’s Health Care, London, Ontario, Canada, and 5Department of Physical Medicine and Rehabilitation, Western University, London, Ontario, Canada Abstract
Purpose: The purpose of this study is to examine the performance of a shortened version of the MoCA (miniMoCA), as a clinical cognitive impairment screening tool in stroke rehabilitation patients. Methods: Cognitive status was assessed using the MoCA and Cognistat in 72 patients. Agreement between the tests was assessed using the Kappa statistic. The sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of a miniMoCA to a MoCA score 526 was also examined. Results: A significant level of agreement was found between the MoCA and miniMoCA to the Cognistat in classifying patients by level of cognitive function. The miniMoCA showed a sensitivity of 93% and specificity of 92% (PPV 98%, NPV 75%) to abnormal MoCA scores (526). Conclusions: This study extends the utility of the miniMoCA as an optimal brief screening tool for cognitive impairment in stroke patients. Further research is needed to determine the validity of the miniMoCA against a neuropsychological test.
Cognistat, mini Montreal Cognitive Assessment (miniMoCA), stroke History Received 3 July 2014 Revised 23 April 2015 Accepted 30 April 2015 Published online 29 June 2015
ä Implications for Rehabilitation
Although the Montreal Cognitive Assessment (MoCA) is a recommended tool to screen for cognitive impairment in stroke patients, its lengthy administration can lead to inconsistent screening of patients for post-stroke cognitive function. In the current work, a shortened version of the MoCA (miniMoCA) was administered in a sample of stoke inpatients, utilizing only five of the eight original subtests. The proposed miniMoCA was found to streamline the administration of this screen test, while maintaining a heightened level of sensitivity for accurately identifying which patients do not require a more in-depth cognitive assessment.
Introduction Cognitive impairment (CI) is common after stroke, with as many as two-thirds of patients experiencing a deficit or decline . Impairments in cognition following a stroke have several clinical and prognostic implications including reduced performance on activities of daily living , increased dependency , longer duration of rehabilitation , and an increased risk for dementia  and death . Early detection of CI is an important part of rehabilitation management. Prompt recognition of deficits allows for more complete assessments and interventions targeting cognitive deficits and should help to guide interventions to prevent subsequent deterioration.
Address for correspondence: Nerissa Campbell, Lawson Health Research Institute, St. Joseph’s Health Care, London, Ontario, Canada N6A 4H1. Tel: +1 519 646 6100x42630. Fax: +1 519 685 4023. E-mail: [email protected]
The gold standard for diagnosis of CI is comprehensive neuropsychological examination, which is costly to the system and burdensome to the patient. Screening, as secondary prevention, saves scarce resources through the application of faster, inexpensive and less invasive tests to identify people who should be referred for definitive testing. Accordingly, a two-stage screen and assess approach has been adopted by the Canadian Best Practice Recommendations for Stroke Care whereby an initial screening identifies those patients who will receive a more detailed cognitive assessment. While there is no consensus on the ideal screening tool, the Canadian Best Practice Recommendations highlight the Montreal Cognitive Assessment test (MoCA), which assesses cognitive functioning in several domains and has demonstrated validity, reliability and sensitivity for detecting CI post-stroke [7,8]. There is still debate regarding what the optimal MoCA cut-off score is for detecting CI in stroke populations; however, the published cut-off score (526) is traditionally used for stroke populations [8,9].
N. Campbell et al.
The MoCA is reported to have an average administration time of approximately 10 minutes, although previous work in stroke patients has found, it can take up to 30 minutes . To decrease the administration time and increase the utility of the MoCA in clinical settings, Bocti et al.  provided empirical validation for a shortened version of the MoCA (miniMoCA), with adequate prediction of abnormal MoCA scores (526) in acute stroke patients. In contrast to the full MoCA, a miniMoCA offers increased feasibility as a CI screening tool across the continuum of stroke care; however, little (if any) research has investigated the performance similarities between these two tests for detecting CI outside an acute care setting. Therefore, the aim of this study was to evaluate the miniMoCA as a screening tool for CI in a sample of stroke rehabilitation patients. The level of agreement between the MoCA and miniMoCA was examined, using the Cognistat (formally known as the Neurobehavioral Cognitive Status Examination) as a criterion for CI. Furthermore, we examined the test performance of the miniMoCA against the complete MoCA.
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language (comprehension, repetition, naming), constructional ability, memory, calculation and reasoning (similarities and judgement ). Each subtest can be scored individually or summed together (total score out of 82), indicative of an overall level of cognitive function. A higher score indicates better cognitive function. The Cognistat employs a screen-metric approach where for eight of the 10 subtests, a patient is administered a fairly challenging screen item. If the patient passes the screen item, they are presumed to function normally and move forward to the next subtest. If a patient fails the screen item, they are then administered simpler metric in that domain. While this approach streamlines administering the Cognistat, doubts have been raised about its reliability . In accordance with recent work , all patients were administered the Cognistat in full, including both the screen and metric items. A total Cognistat score was calculated for each participant. In line with previous work in stroke patients , we set the Cognistat cut-off for the detection of CI at 565.
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Methods Participants and procedures Patients were recruited from a stroke rehabilitation inpatient unit at Parkwood Hospital, St. Joseph’s Healthcare in London, ON, between August of 2011 and March of 2012. Patients diagnosed as aphasic or dysphasic, having severe hearing or visual limitations, and/or unable to speak or read English were ineligible. All eligible patients were given a letter of information outlining the purpose and procedures of the study. Signed consent was obtained from those interested in participating. Patients were screened for CI using two independent screening tools. Ethics approval was obtained prior to study initiation from the University of Western Ontario Research Ethic Board (REB #18099). Assessments Each patient was screened for cognitive deficits using the MoCA and Cognistat. The MoCA and Cognistat were administered to patients during two separate sessions by an Occupational Therapist (OT) and trained student investigator, respectively. All patients completed the MoCA first, followed by the Cognistat within a 24-h period.
Agreement between the MoCA and Cognistat for classifying patients as cognitively impaired or unimpaired was estimated using the Kappa statistic. Both statistical procedures were repeated to examine the miniMoCA against the Cognistat and to investigate how well the miniMoCA performed in contrast to the full MoCA. Finally, to examine the performance of the miniMoCA, we calculated the sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively) to an abnormal MoCA score (526).
Results The total number of patients registered for rehabilitation in the inpatient unit during the study period was 144; cognitive assessment was completed in 72 patients (see Figure 1). Thirtyseven out of the 72 participants were female. The mean (standard deviation) age of our participants was 68.1 (15) years with a mean education level of 11.2 (2) years. The mean scores obtained on the MoCA, miniMoCA and Cognistat were 20.7/30 (±5.3), 4.3/10 (±2.7) and 62.5/72 (±9.9), respectively. See Table 1 for patients’ mean scores for each of the independent MoCA and Cognistat subtests. A significant level of agreement was found between the MoCA and Cognistat, k ¼ 0.38, p50.005. See Table 2 for a cross
MoCA The MoCA consists of eight subtests and assesses cognitive function in a variety of domains: memory and delayed recall, visuospatial abilities, executive functions, attention, concentration, working memory, language and orientation to time and place. MoCA scores range from 0 to 30 with a higher score indicating better cognitive performance. In accordance with the original instructions, MoCA scores were adjusted for education level by adding one point to the total score of patients who had 512 years of education . The published cut-off score of 526 was used to classify patients as having a possible CI . Cognitive function was also assessed using a shortened version of the complete MoCA . A total score out of 10 was calculated based on patients’ performance on five MoCA subtest items (verbal fluency, cube copy, trail making, five-word recall and abstraction). A cut-off score for detecting CI was set at57/10 . Cognistat The Cognistat consists of 10 individual subtests and is designed to assess a variety of cognitive functions: orientation, attention,
Total number of stroke patients admitted to the rehabilitation inpatient unit (Aug – Nov, 2011) N = 144
Eligible patients at screening N = 80
Total number of patients who completed both cognitive assessments
Patients excluded (n = 64) • Aphasic/dysphasic (n = 44) • Language barrier (n = 9) • Other (n = 11) Patients excluded (n = 8) • No consent (n = 4) • No MoCA (n = 3) • No Cognistat (n = 1)
N = 72
Figure 1. Participant flowchart.
MiniMoCA in stroke
Table 1. Descriptive statistics for each test factor on the MoCA. Domain
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Visuospatial/executive (VE) Trail making Cube copy Clock drawing Subtotal (VE) Naming Attention Digit span Letter A Serial 7 Subtotal (attention) Language Sentence repeat Fluency Subtotal (language) Abstraction Delayed recall orientation
0.44 0.26 2.08 2.79 2.67
(0.50) (0.44) (0.82) (1.36) (0.58)
0 0 0 0 1
1 1 3 5 3
1.60 0.74 2.28 4.61
(0.57) (0.44) (0.94) (1.45)
0 0 0 1
2 1 3 6
1.28 0.24 1.51 1.28 2.06 5.24
(0.72) (0.43) (0.93) (0.80) (1.68) (1.27)
0 0 0 0 0 1
2 1 3 2 5 6
Table 2. Cross classification of the number (percentage) of patients who screened positive or negative for cognitive impairment by the MoCA and miniMoCA. Cognistat score
MoCA score 526 426 MiniMoCA 57 47
37 (51%) 0
22 (31%) 13 (18%)
36 (50%) 1 (1%)
20 (28%) 15 (21%)
classification of patients by each screening tool. With respect to the miniMoCA, a significant level of agreement was also found with the Cognistat, k ¼ 0.41, p50.005. The miniMoCA yielded a good prediction for abnormal MoCA scores (526). It was found to have high levels of sensitivity and specificity (93% and 92%, respectively) in addition to a high PPV (98%) and adequate NPV (75%).
Discussion In this study, we examined the utility of a provisional miniMoCA, in contrast to the full MoCA, for detecting CI in a sample of stroke rehabilitation patients. Both tests showed a significant level of agreement with the Cognistat for estimating the prevalence of CI in the current sample. The MoCA and Cognistat mutually agreed in classifying 69% of the patients as either cognitively impaired or unimpaired (51% and 18%, respectively). Mutual agreement increased to 71% with respect to the miniMoCA, whereby 50% and 21% of the patients were jointly categorized as impaired and unimpaired, respectively. Altogether, only one false positive screen (565 on Cognistat but 47 on miniMoCA) occurred using the miniMoCA, although there was none found with the full MoCA based on the Cognistat scores. In contrast to a dichotomized full MoCA score of 526, the miniMoCA was found to have a high screen performance, more specifically, a sensitivity of 93% and a specificity of 92%. The current levels of sensitivity and specificity are greater than those initially reported by Bocti et al.  (91% and 83%, respectively) when investigating the performance of the miniMoCA in acute stroke patients. The major advantages of the MoCA over other CI
screening tools in stroke populations (i.e. Mini-Mental State Examination) include a heightened sensitivity for assessing memory and evaluating executive functioning . Inclusion (or retention) of memory and executive function subtests on the miniMoCA may help in explaining the high levels of sensitivity found when using this tool in stroke patients. In the current study, we calculated a miniMoCA score from the patients’ full MoCA; however, when testing just the five miniMoCA subtests, it is important that the order in which these items are traditionally given is altered, to ensure an adequate amount of time (delay) is achieved between when the five words of the memory subtest (five word recall) are presented and recalled by the patient. The major limitation to the current work is the lack of an independent neuropsychological battery to compare the MoCA (and miniMoCA) results. We used the Cognistat as the criterion measure of CI. When evaluated against a full neuropsychological assessment, the Cognistat has been found to have adequate level of sensitivity (82%) and an acceptable level of specificity (50%) . Similar to a complete neuropsychological assessment, the Cognistat provides a differentiated profile of a patient’s cognitive function, reflective of independent function for each of the cognitive domains assessed. Due to a lack of normative data, there is still a debate regarding what the MoCA cut-off score should be for detecting CI in stroke patients. The published cut-off score of 526 used in the present study has been shown to provide adequate sensitivity for detecting CI in stroke patients [7,14]; however, recently its specificity has been questioned when compared with a neuropsychological assessment . Regardless, high levels of sensitivity found with the MoCA, and miniMoCA presently, demonstrate accuracy by both these screening tools for identifying stroke patients for which a full cognitive assessment can be ruled out. Furthermore, patients with 512 years of education are given an extra point to their final MoCA score. In accordance with the Bocti et al.  study, no adjustments were made for patients’ education level with respect to their miniMoCA scores. Given the recent findings that less education significantly impacts MoCA performance [16,17], the influence of education level on the miniMoCA score should be investigated. In summary, the importance of identifying CI in stroke patients has been described previously, whereby early detection of CI facilitates in reducing further cognitive decline and implementing appropriate and effective rehabilitation strategies. The development of a provisional five-item miniMoCA by Bocti et al.  offers an ultra-brief yet practical CI screening tool to be used in clinical stroke patients. This study provides additional support for the five-item miniMoCA, as a valid CI screening tool in stroke; however, further validation is required before it can be utilized in clinical settings. In particular, further research is required to assess the miniMoCA’s validity against a gold standard neuropsychological test.
Acknowledgements The authors would like to thank the Occupational Therapists: Stefanie Balcarras, Janet Donais, Nicole McLean, Tricia Shoniker, and Helena Steinmetz, for helping administer the MoCA and Cognistat to patients, respectively. Furthermore we are grateful to Eileen Britt, clinical coordinator for the Inpatient Rehabilitation Unit, for assisting with patient recruitment.
Declaration of interest The authors report no declarations of interest. This work was supported by the Canadian Stroke Network. The Canadian Stroke Network did not play a role in the design, execution, analysis and interpretation of data, or writing of the study.
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