Tangwongchai Sa, Charernboon Tc , Phanasathit Mc, Akkayagorn La, Hemrungrojn Sa, Phanthumchinda Kb, Nasreddine ZSd
aDepartment of Psychiatry, Faculty of Medicine, Chulalongkorn University ,Bangkok , Thailand.
bDivision of Neurology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
cDepartment of Psychiatry, Faculty of Medicine, Thammasat University, Phratumthani, Thailand
dCenter for Clinical Research, Neurology Service, Hôpital Charles LeMoyne, Quebec, Canada; Department of Clinical Neurosciences and Division of Geriatric Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University and Division of Geriatric Medicine, Montreal, Quebec, Canada.
For reference: Tangwongchai S, Phanasathit M, Charernboon T, Akkayagorn L, Hemrungrojn S, Phanthumchinda K, Nasreddine ZA. The Validity of Thai version of The Montreal Cognitive Assessment (MoCA-T), Dement Neuropsychol 2009;3(2):172 (Abstract Only)
Abstract
Rational and objective: Mild Cognitive impairment(MCI) is the prodrome of dementia or incipient dementia that is challenging in clinical practice. The Montreal Cognitive Assessment ( MoCA) test has been demonstrated to be valid and reliable instrument for screening of MCI in various cross-cultural clinical samples. The objective of this study is to examine the validity and reliability of the Thai version of The MoCA test in screening for patients with amnestic MCI ( aMCI) by using Clinical Dementia Rating Scale( CDR ) as the gold standard.
Method :The sample composed of 120 subjects consecutively included from the memory clinic at a university hospital, the King Chulalongkorn Memorial Hospital, in Bangkok, Thailand. 40 patients were diagnosed as aMCI with CDR stage 0.5 and 40 patients had been treated for mild Alzheimer’s disease (AD) according to NINCDS-ADRDA ,DSM IV-TR criteria and CDR stage 1 . 40 relatives of the geriatric patients visiting our memory clinic were randomly selected as normal subjects with CDR stage 0. All subjects completed the Thai Geriatric Depressive Rating Scale(TGDS). Thai version of MMSE(TMSE) , MoCA-Thai , and CDR were administered by trained psychiatrists. Written informed consents were given by the patients or authorizing caregivers. The internal consistency and criterion validity of MoCA-T was explored and compared with the CDR as the gold standard for diagnosis of MCI.
Result: The internal consistency of MoCA-T was demonstrated to have the Cronbach’s alpha coefficient of 0.914. Score of MoCA and MMSE were found to be highly correlated with r = 0.900 (p<0.001). Age, year of education and depressive score were significantly correlated with MoCA score . From multiple regression analysis , The global CDR score and year of education were the significant predictors for score of MoCA. With the cut off score under 25 and 22 by adding 1 point for subjects with ≤ 6 years of education , the sensitivity and specificity were 0.8 and 0.80 for aMCI , 1.0 and 0.98 for AD.
Conclusion: MoCA-T showed a lower cut off score comparing to the original version. MoCA-T is a reliable and valid screening tool for diagnosis of aMCI in Thai clinical sample.
Introduction
Mild Cognitive Impairment ( MCI ) is the clinical state, first mentioned by Petersen RC1. Since MCI is a transitional stage between normal aging and dementia, which needs comprehensive and time consuming diagnostic process, brief screening methods are needed for the detection of MCI . Several tools have been examined to look for the reliable and valid instruments in clinical practice. Montreal Cognitive Assessment(MoCA) was developed and validated by Nasreddine Z. ( 2) as an effective screening tool for MCI. Several non-English version of MoCA were validated and demonstrated a good validity (3,4,5 ). For the score below 1.5 SD of standard cognitive test from normal population matched with age and education is required as the objective evidence in Petersen’s criteria to diagnosis of MCI, It was complicated for the internist or general practitioners to diagnose patients with suspected MCI. As the elderly is increasing in number in Thailand as found in other countries , screening tool for MCI is needed for the better care of geriatric population.
Objective
To validate and find the appropriate cut off score of MoCA-T in clinical setting by using the Clinical Dementia Rating Scale ( CDR) as the gold standard.
Subjects and method
Geriatric patients or relatives aged between 60-90 years old were consecutively included from memory clinic at King Chulalongkorn Memorial hospital. All enrolled subjects were literated and had no previously diagnosis for stroke , psychiatric disorder , neurologic or serious medical conditions other than memory complaints or dementia. The normal control ( NC ) subjects were the relatives or spouses, who accompanied the patients to memory clinic, with TMSE6 score ≥ 24 and CDR stage 0. The MCI subjects were patients , who visited memory clinic with memory complaints , had TMSE score ≥ 24 and CDR stage o.5 . The demented group was patients diagnosed as possible or probable Alzheimer’s disease according to NINCDS-ADRDA or DVM IV-TR criteria with the score of TMSE between 10 - 23 and CDR stage 1-2 . According to the original MoCA reported the sensitivity to be 0.9 , the sample size was calculated and it was indicated that at least 36 subjects required in each group to validate MoCA-T. So we included 40 subjects for each of 3 group ; normal control( NC) , amnestic MCI ( aMCI) and mild to moderate Alzheimer’s disease.
The MoCA was translated into Thai and back translated by a linguistic at Chulolongkron Language Institute. Content validity was also verified by 2 psychiatrists and 1 neurologist . All participants complete the self rating questionnaire , Thai Geriatric Depressive Scale – 307 (TGDS). CDR Thai version and TMSE were used to assess all subjects and their relatives by one trained psychiatrist, then MoCA-T was administered by another trained psychiatrist to complete the assessment.
This study has been approved by the Ethical Committee in Human Research of Faculty of Medicine, Chulalongkorn University. Every subject was asked to provide the written informed consents
Result
Demographic data: The basic characteristics for subjects included in each group were as presented in table 1 .
Table 1 Demographic and clinical characteristics of subjects
| | AD (A) n=40 | MCI (B) n=40 | NC (C) n=40 | ANOVA post hoc analysis Bonferroni method |
| Age, years (SD) | 77.38 (8.96) | 73.42 (7.32) | 69.58 (6.60) | A>C** |
| Female , N (%) | 30 (75.0) | 26 (65.0) | 29 (72.5) | n.s. |
| Education years (SD) | 8.45 (5.38) | 11.30 (5.26) | 12.02 (5.33) | A<C* |
| TMSE scores (SD) | 20.78 (4.48) | 26.52 (1.99) | 28.50 (1.57) | A<B<C** |
| TGDS scores (SD) MoCA-Thai scores (SD) | 6.52 (4.55) 11.48(4.67) | 5.60 (4.61) 21.30 (3.64) | 3.60 (3.82) 25.9 (2.14) | A>C* A<B<C** |
Abbreviations: TMSE, Thai-Mental State Examination; TGDS, Thai Geriatric Depression Scale; SD, standard deviation.
*p<0.05, **p<0.001
Reliability : The internal consistency of MoCA-T was demonstrated to have the over all cronbach’s alpha coefficient of 0.914. Item deleted cronbach’s alpha coefficients were presented in table 2.
Table 2. Item deleted Cronbach’s alpha coefficient
| | Mean if Item Deleted | Variance if Item Deleted | Corrected Item-Total Correlation | Cronbach's Alpha if Item Deleted |
| Trail making B | 19.02 | 44.454 | .720 | .907 |
| Cubic | 19.10 | 45.368 | .577 | .910 |
| Clock circle | 18.64 | 48.383 | .272 | .914 |
| Clock number | 18.87 | 45.159 | .664 | .908 |
| Clock time | 18.99 | 44.344 | .742 | .907 |
| Animal naming 1 | 18.63 | 48.236 | .348 | .913 |
| Animal naming 2 | 18.79 | 46.133 | .554 | .910 |
| Animal naming 3 | 18.65 | 48.028 | .348 | .913 |
| Digit forward | 18.64 | 48.736 | .180 | .915 |
| Digit backward | 18.75 | 47.399 | .359 | .913 |
| Vigilance | 18.74 | 46.445 | .550 | .911 |
| Serial 7 | 17.28 | 41.478 | .600 | .913 |
| Sentence repetition 1 | 19.05 | 45.930 | .489 | .911 |
| Sentence repetition 2 | 19.16 | 45.849 | .513 | .911 |
| Word fluency | 19.10 | 45.855 | .502 | .911 |
| Abstract1 | 19.04 | 46.007 | .478 | .912 |
| Abstract2 | 19.15 | 45.910 | .502 | .911 |
| Delayed recall - face | 19.26 | 46.412 | .460 | .912 |
| Delayed recall - silk | 19.18 | 46.050 | .488 | .911 |
| Delayed recall -temple | 19.15 | 45.675 | .538 | .911 |
| Delayed recall -jasmine | 19.23 | 45.861 | .538 | .911 |
| Delayed recall -red | 19.18 | 46.431 | .427 | .913 |
| Orientation - date | 18.88 | 45.472 | .606 | .909 |
| Orientation - month | 18.80 | 45.523 | .655 | .909 |
| Orientation - year | 18.77 | 45.676 | .665 | .909 |
| Orientation - day | 18.82 | 45.764 | .597 | .910 |
| Orientation - place | 18.61 | 48.526 | .307 | .914 |
| Orientation - province | 18.62 | 48.003 | .445 | .913 |
Concurrent validity : The global CDR score and MoCA-T showed significantly negative correlation with Pearson correlation (r) of -0.832 (p<0.001). MoCA-T score also had significantly positive correlation with TMSE ( r = 0.862 , p<0.001).
Correlated factors for score of MoCA-T
By performing univariate analysis , it was found that older age , female gender , year of education, TGDS score were significantly associated factors with the score of MoCA-T in these population. After adjusting for these factor by performing multiple regression analysis , only the global CDR score and year of education were remained as the predictor for the score of MoCA , as showed in the following equation.
For Thai elderly has average years of education lower than those in western countries, one point added up for subjects with year of education less than 12 in original version of MoCA was not applicable for MoCA-T. To verify how to compensate for education level in this study, we proposed to add one point for less than 6 years , less than 9 years, and at least 12 years of education to calculate the parameters of criterion validity as showed in table 3.
Table 3. Criterion Validity of MoCA-T
| Cut-off score | Sensitivity | Specificity | PPV | NPV | Accuracy |
| Not point added for YE · 23/24 · 24/25 · 25/26 | 0.70 0.80 0.90 | 0.85 0.75 0.58 | 0.82 0.76 0.68 | 0.74 0.79 0.85 | 0.78 0.78 0.74 |
| 1 point added for YE ≤ 6 · 23/24 · 24/25 · 25/26 | 0.70 0.80 0.90 | 0.92 0.80 0.60 | 0.90 0.80 0.69 | 0.76 0.80 0.85 | 0.81 0.80 0.75 |
| 1 point added for YE ≤ 9 · 23/24 · 24/25 · 25/26 | 0.70 0.78 0.90 | 0.92 0.80 0.65 | 0.90 0.79 0.72 | 0.76 0.78 0.87 | 0.81 0.79 0.78 |
| 1 point added for YE ≤ 12 · 23/24 · 24/25 · 25/26 | 0.62 0.78 0.88 | 0.92 0.80 0.65 | 0.89 0.79 0.71 | 0.71 0.78 0.84 | 0.78 0.78 0.76 |
YE = year of education
By adding one point for year of education ≤ 6 , the score under 22 of MoCA -T showed the sensitivity of 100% , specificity of 98% , PPV of 98% , NPV of 100% , accuracy of 98% for patients with dementia of Alzheimer type .
Conclusion
The MoCA-T was translated and validated in this study . It was found to have good internal consistency and highly correlate with TMSE score . Year of education was significant factor correlated with the score of MoCA-T. The compensation by adding 1 point for subjects with year of education ≤ 6 was considered to be more appropiate in Thai subjects. The score ≤ 24 of MoCA appeared to be the accurate cut of point which showed the sensitivity of 0.8 and specificity of 0.8. MoCA-T is a reliable brief screening tool for the detection of amnestic MCI in clinical setting for literated Thai elderly.
Reference
1. Petersen RC, Smith GE, Waring SC et al. Mild cognitive impairment. Clinical characterization and outcome. Arch Neurol 1999;56 : 303-8.
2. Nasreddine ZS, Phillips NA, Bédirian V et al. The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment. J Am Geriatr Soc 2005 ; 53:695-9.
3. Smith T, GilDeh N, Holmes C. The Montreal Cognitive Assessment : validity and utility in a memory clinic setting . Can J Psychiatry 2007 ; 52 : 329-332.
4. Lee JY, Lee DW , Cho SJ et al . Brief screening for mild cognitive impairment in elderly outpatient clinic: validity of the Korean version of the Montreal Cognitive Assessment. J Geriatr Psychiatry Neurol 2008 ; 21: 104-110.
5. Rahman TT, El Gaafary MM. Montreal Cognitive Assessment Arabic version: reliability and validity prevalence of mild cognitive impairment among elderly attending geriatric clubs in Cairo. Geriatr Gerontol Int 2009; 9: 54-61.
6. Train the Brian Forum Committee ( Thailand ). Thai Mental State Examination - TMSE . Siriraj Hospital Gazette 1993; 45: 359-374.
7. Train the Brian Forum Committee ( Thailand ). Thai Geriatric Depressive Scale – TGDS. Siriraj Hospital Gazette 1994; 46: 1 -9.
