Wee Shiong Lim

Ministry of Health, Singapore, Tumasik, Singapore

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Publications (46)255.47 Total impact

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    ABSTRACT: The availability of empirical data from human studies in recent years have lend credence to the old axiomatic wisdom that health benefits of tea drinking extend to the area of cognition. Specifically, there is increasing interest as to whether tea drinking can delay or even prevent the onset of Alzheimer's disease (AD). Data from several cross-sectional studies have consistently shown that tea drinking is associated with better performance on cognitive tests. This association is supported by longitudinal data from the Singapore Longitudinal Aging Study, the Chinese Longitudinal Healthy Longevity Survey and the Cardiovascular Health Study. The only two published longitudinal analyses on clinical outcome reported conflicting results: one study reported that mid-life tea drinking was not associated with risk reduction of Alzheimer's disease in late life while the other one found that green tea consumption reduced the incidence of dementia or mild cognitive impairment. Two small trials from Korea and Japan reported encouraging but preliminary results. While the existing evidence precludes a definite conclusion as to whether tea drinking can be an effective and simple lifestyle preventive measure for AD, further research involving longer-term longitudinal studies and randomized controlled trials is clearly warranted to shed light on this topic of immense public health interest. Biological markers of tea consumption and Alzheimer diseases should be employed in future research to better delineate the underlying mechanisms of tea drinking's protective effect on cognition.
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    ABSTRACT: To investigate the utility of the Severe Impairment Rating Scale (SIRS) as a cognitive assessment tool among nursing home residents with advanced dementia, we conducted a cross-sectional study of 96 residents in 3 nursing homes with Functional Assessment Staging Test (FAST) stage 6a and above. We compared the discriminatory ability of SIRS with the Chinese version of Mini-Mental State Examination, Abbreviated Mental Test, and Clock Drawing Test. Among the cognitive tests, SIRS showed the least "floor" effect and had the best capacity to distinguish very severe (FAST stages 7d-f) dementia (area under the curve 0.80 vs 0.46-0.76 for the other tools). The SIRS had the best correlation with FAST staging (r = -.59, P < .01) and, unlike the other 3 tools, exhibited only minimal change in correlation when adjusted for education and ethnicity. Our results support the utility of SIRS as a brief cognitive assessment tool for advanced dementia in the nursing home setting. © The Author(s) 2015.
    American Journal of Alzheimer s Disease and Other Dementias 05/2015; DOI:10.1177/1533317515587085 · 1.43 Impact Factor
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    ABSTRACT: The Zarit Burden Interview allows caregiver burden to be interpreted from a total score. However, recent studies propose a multidimensional Zarit Burden Interview model. This study aims to determine the agreement between unidimensional (UD) and multidimensional (MD) classification of burden, and differences in predictors among identified groups. We studied 165 dyads of dementia patients and primary caregivers. Caregivers were dichotomized into low-burden and high-burden groups based upon: (1) UD score using quartile cutoffs; and (2) MD model via exploratory cluster analysis. We compared UD versus MD 2×2 classification of burden using κ statistics. Caregivers not showing agreement by either definition were classified as "intermediate" burden. We performed binary logistic regression to ascertain differences in predictive factors. The 2 models showed moderate agreement (κ=0.72, P<0.01), yielding 104 low, 20 intermediate (UD "low burden"/MD "high burden"), and 41 high-burden caregivers. Neuropsychiatric symptoms [odds ratio (OR)=1.27, P=0.003], coresidence (OR=6.32, P=0.040), and decreased caregiving hours (OR=0.99, P=0.018) were associated with intermediate burden, whereas neuropsychiatric symptoms (OR=1.21, P=0.001) and adult children caregivers (OR=2.80, P=0.055) were associated with high burden. Our results highlight the differences between UD and MD classification of caregiver burden. Future studies should explore the significance of the noncongruent intermediate group and its predictors.
    Alzheimer Disease and Associated Disorders 02/2015; DOI:10.1097/WAD.0000000000000085 · 2.69 Impact Factor
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    ABSTRACT: A new interprofessional geriatric medicine curriculum was recently introduced at a large undergraduate Asian medical school. A longitudinal controlled interventional cohort study was conducted to evaluate the effect of the new curriculum on the knowledge and attitudes of medical students. The medical students under the new curriculum formed the intervention cohort, and those under the former curriculum formed the control cohort. To test knowledge, the University of California at Los Angeles (UCLA) geriatrics knowledge test (GKT) was used in Year 2 and the University of Michigan GKT in Year 5. Geriatrics attitudes were evaluated using the UCLA geriatrics attitudes test in Years 2 and 5. Not surprisingly, geriatrics knowledge at the end of Year 5 of medical school was enhanced to a greater degree in the intervention cohort than the control cohort, although improvements in geriatrics attitudes in each cohort were of similar magnitude by the end of Year 5, suggesting that factors other than a formal geriatrics curriculum influenced the improvements in geriatrics attitudes. This article is one of few published on the effectiveness of geriatrics curricular innovations using validated knowledge and attitude outcomes in a longitudinal controlled study design and will be useful to other medical institutions seeking to improve the geriatrics knowledge and attitudes of their students. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.
    Journal of the American Geriatrics Society 02/2015; 63(3). DOI:10.1111/jgs.13295 · 4.22 Impact Factor
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    ABSTRACT: To examine diagnostic agreement between Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) Neurocognitive Disorders (NCDs) criteria and DSM, Fourth Edition (DSM-IV) criteria for dementia and International Working Group (IWG) criteria for mild cognitive impairment (MCI) and DSM-V's impact on diagnostic classifications of NCDs. The authors further examined clinical factors for discrepancy in diagnostic classifications between the different operational definitions. Using a cross-sectional study in tertiary memory clinic, the authors studied consecutive new patients aged 55 years or older who presented with cognitive symptoms. Dementia severity was scored based on the Clinical Dementia Rating scale (CDR). All patients completed neuropsychological evaluation. Agreement in diagnostic classifications between DSM-IV/IWG and DSM-V was examined using the kappa test and AC1 statistic, with multinomial logistic regression for factors contributing to MCI reclassification as major NCDs as opposed to diagnostically concordant MCI and dementia groups. Of 234 patients studied, 166 patients achieved concordant diagnostic classifications, with overall kappa of 0.41. Eighty-six patients (36.7%) were diagnosed with MCI and 131 (56.0%) with DSM-IV-defined dementia. With DSM-V, 40 patients (17.1%) were classified as mild NCDs and 183 (78.2%) as major NCDs, representing a 39.7% increase in frequency of dementia diagnoses. CDR sum-of-boxes score contributed independently to differentiation of MCI patients reclassified as mild versus major NCDs (OR: 0.01; 95% CI: 0-0.09). CDR sum-of-boxes score (OR: 5.18; 95% CI: 2.04-13.15), performance in amnestic (OR: 0.14; 95% CI: 0.06-0.34) and language (Boston naming: OR: 0.52; 95% CI: 0.29-0.94) tests, were independent determinants of diagnostically concordant dementia diagnosis. The authors observed moderate agreement between the different operational definitions and a 40% increase in dementia diagnoses with operationalization of the DSM-V criteria. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.
    The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 01/2015; DOI:10.1016/j.jagp.2015.01.004 · 3.52 Impact Factor
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    ABSTRACT: Background: The Montreal Cognitive Assessment (MoCA) was developed as a screening instrument for mild cognitive impairment (MCI). We evaluated the MoCA's test performance by educational groups among older Singaporean Chinese adults. Method: The MoCA and Mini-Mental State Examination (MMSE) were evaluated in two independent studies (clinic-based sample and community-based sample) of MCI and normal cognition (NC) controls, using receiver operating characteristic curve analyses: area under the curve (AUC), sensitivity (Sn), and specificity (Sp). Results: The MoCA modestly discriminated MCI from NC in both study samples (AUC = 0.63 and 0.65): Sn = 0.64 and Sp = 0.36 at a cut-off of 28/29 in the clinic-based sample, and Sn = 0.65 and Sp = 0.55 at a cut-off of 22/23 in the community-based sample. The MoCA's test performance was least satisfactory in the highest (>6 years) education group: AUC = 0.50 (p = 0.98), Sn = 0.54, and Sp = 0.51 at a cut-off of 27/28. Overall, the MoCA's test performance was not better than that of the MMSE. In multivariate analyses controlling for age and gender, MCI diagnosis was associated with a <1-point decrement in MoCA score (η(2) = 0.010), but lower (1-6 years) and no education was associated with a 3- to 5-point decrement (η(2) = 0.115 and η(2) = 0.162, respectively). Conclusion: The MoCA's ability to discriminate MCI from NC was modest in this Chinese population, because it was far more sensitive to the effect of education than MCI diagnosis. © 2015 S. Karger AG, Basel.
    Dementia and Geriatric Cognitive Disorders 01/2015; 39(3-4):176-185. DOI:10.1159/000368827 · 2.81 Impact Factor
  • Wee Shiong Lim, Y Y Ding
    Annals of the Academy of Medicine, Singapore 01/2015; 44(1):1-5. · 1.22 Impact Factor
  • Aik Phon Chew, Wee Shiong Lim, Keng Teng Tan
    Journal of the American Geriatrics Society 10/2014; 62(10). DOI:10.1111/jgs.13023 · 4.22 Impact Factor
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    ABSTRACT: We previously reported TOMM40 to be significantly down-regulated in whole blood of Alzheimer's disease (AD) subjects at baseline and after one-year. In this longitudinal follow-up study of TOMM40 expression up to 2 years, we performed 6-monthly assessments for the first year and 2nd year blood sampling on 27 probable AD subjects compared with age- and gender-matched controls. TOMM40 gene expression remained significantly lower in AD patients at all time-points compared to controls, supported by confirmatory RT-PCR results. Our findings of consistently lower TOMM40 expression on longitudinal 2-year sampling support its potential role as a diagnostic blood AD biomarker.
    Journal of Alzheimer's disease: JAD 09/2014; 44(1). DOI:10.3233/JAD-141590 · 3.61 Impact Factor
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    ABSTRACT: Objectives Conventional practice in assessing cognitive status and monitoring change over time in older adults using normative values of Mini-Mental State Examination (MMSE) based on age bands is imprecise. Moreover, population-based normative data on change in MMSE score over time are scarce and crude, as they do not include age and education specific norms. This study aims to develop unconditional standards for assessing current cognitive status and conditional standards that take prior MMSE score into account for assessing longitudinal change, with percentile curves as smooth functions of age. Design Cross-sectional and prospective cohort 4 years follow up study. Setting General community. Participants 2026 Chinese old adults aged 55 to 84 from the Singapore Longitudinal Aging Study (SLAS) Measure ments Cross-sectional and longitudinal data of a modified version of MMSE for older Chinese adults in Singapore were used to estimate quantile regression coefficients and create unconditional standards and conditional standards. Results We presented MMSE percentile curves as smooth function of age in education strata, for unconditional and conditional standards, based on quantile regression coefficient estimates. We found that the 5th and 10th percentiles were more strongly associated with age and education than the higher percentiles were. Model diagnostics demonstrated the accuracy of the standards. Conclusions The development and use of unconditional and conditional standards should facilitate cognitive assessment in clinical practice and deserve further studies.
    American Journal of Geriatric Psychiatry 08/2014; DOI:10.1016/j.jagp.2014.08.008 · 3.52 Impact Factor
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    ABSTRACT: ABSTRACT Background: Discordance between patient- and caregiver-reported quality of life (QoL) is well recognized. This study sought to (i) identify predictors of discrepancy between patient- and caregiver-rated QoL amongst community-dwelling persons with mild-to-moderate dementia, and (ii) differentiate between patients who systematically rate their QoL lower versus those who rate their QoL higher relative to their caregiver ratings. Methods: We recruited 165 patient-caregiver dyads with mild-to-moderate dementia. Quality of life in Alzheimer's disease (QoL-AD) scale was administered separately to patients and caregivers. Data on socio-demographics, interpersonal relationship, and disease-related characteristics (cognitive performance, mood, neuropsychiatric symptoms, functional ability, and caregiver burden) were collected. Patient-caregiver dyads were categorized based on whether patient-rated QoL was lower or higher than their respective caregiver ratings. Univariate analyses and multiple regression models were performed to identify predictors of dyadic rating discrepancy. Results: Mean patient-rated QoL was significantly higher than caregiver rating (mean difference: 3.8 ± 7.1, p < 0.001). Majority (111 (67.2%)) of patients had more positive self-perceived QoL (QoL-ADp (QoL-AD self rated by the patient) > QoL-ADc (QoL-AD proxy-rated by a caregiver)), compared with those (44 (26.7%)) with poorer self-perceived QoL (QoL-ADp < QoL-ADc). Patient's education level, depressive symptoms, and severity of neuropsychiatric symptoms predicted magnitude of discrepancy. Depression (OR = 1.17, 95% CI = 1.02-1.35) and being cared for by other relative (non-spouse/adult child; OR = 7.54, 95% CI = 1.07-53.03) predicted poorer self-perceived QoL. Conclusions: Dyadic rating discrepancy in QoL should draw the clinician's attention to patient depression and neuropsychiatric symptoms. Consideration should also be given to nature of patient-caregiver relationship when discordance between patient and caregiver assessments of QoL is observed.
    International Psychogeriatrics 08/2014; 26(8):1273-82. DOI:10.1017/S1041610214000660 · 1.89 Impact Factor
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    Alzheimer's and Dementia 07/2014; 10(4):P819-P820. DOI:10.1016/j.jalz.2014.05.1612 · 17.47 Impact Factor
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    ABSTRACT: Abstract The interprofessional team meeting is a model of care in which members of the interprofessional team come together with their individual expertise to provide holistic care for the patient. Additionally, interprofessional team meetings serve as a platform for continuing interprofessional education as healthcare professionals come together to learn with, from, and about each other to enhance collaboration and patient care. Utilizing the transactive memory system (TMS) framework, this paper aims to demonstrate the utility of TMS as a measure of interprofessional collaborative practice based on a pilot study in an interprofessional geriatrics team. Questionnaires were administered to 78 members who regularly participated in the interprofessional team meetings. The quality of perceived TMS was measured by the cumulative scores on two previously validated scales. Logistic regression analyses revealed that TMS was a significant predictor of satisfaction with interprofessional team meeting experience and clinical work, whereas TMS scores significantly increased with greater number of interprofessional team meetings attended. Reliability analysis indicated high internal consistency while in factor analysis, each scale was predicated on a dual factor structure instead of the original tri-dimensional structure. Our results indicate the novel use of TMS as a valid and reliable measure of interprofessional collaborative practice. Implications for the role of TMS in continuous interprofessional education, collaborative practice, and patient care are also presented.
    Journal of Interprofessional Care 04/2014; 28(3). DOI:10.3109/13561820.2014.901938 · 1.36 Impact Factor
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    ABSTRACT: ABSTRACT Background: Recent studies that describe the multidimensionality of the Zarit Burden Interview (ZBI) challenge the traditional dual-factor paradigm of personal and role strains (Whitlatch et al., 1991). These studies consistently reported a distinct dimension of worry about caregiver performance (WaP) comprising items 20 and 21.The present study aims to compare WaP against conventional ZBI domains in a predominantly Chinese multi-ethnic Asian population. Methods: We studied 130 consecutive dyads of family caregivers and patients. Factor analysis of the 22-item ZBI revealed four factors of burden. We compared WaP (factor 4) with the other three factors, personal strain, and role strain via: internal consistency; inter-factor correlation; item-to-total ratio across Clinical Dementia Rating (CDR) stages; predictors of burden; and interaction effect on total ZBI score using two-way analysis of variance. Results: WaP correlated poorly with the other factors (r = 0.05-0.21). It had the highest internal consistency (Cronbach's α = 0.92) among the factors. Unlike other factors, WaP was highly endorsed in mild cognitive impairment and did not increase linearly with disease severity, peaking at CDR 1. Multiple regression revealed younger caregiver age as the major predictor of WaP, compared with behavioral and functional problems for other factors. There was a significant interaction between WaP and psychological strain (p = 0.025). Conclusion: Our results corroborate earlier studies that WaP is a distinct burden dimension not correspondent with traditional ZBI domains. WaP is germane to many Asian societies where obligation values to care for family members are strongly influential. Further studies are needed to better delineate the construct of WaP.
    International Psychogeriatrics 01/2014; 26(4):1-10. DOI:10.1017/S1041610213002445 · 1.89 Impact Factor
  • Journal of the American Geriatrics Society 12/2013; 61(12):2258-2260. DOI:10.1111/jgs.12581 · 4.22 Impact Factor
  • Alzheimer's and Dementia 07/2013; 9(4):P768. DOI:10.1016/j.jalz.2013.05.1559 · 17.47 Impact Factor
  • Alzheimer's and Dementia 07/2013; 9(4):P764. DOI:10.1016/j.jalz.2013.05.1549 · 17.47 Impact Factor
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    ABSTRACT: ABSTRACT Background: Cost of informal care constitutes an important component of total dementia care cost. It also reflects resource utilization by patients and caregivers. We aim to quantify the informal cost of care for mild to moderate dementia patients. Methods: We recruited 165 patient-caregiver dyads with mild to moderate dementia. Informal care burden was assessed using the Resource Utilization in Dementia (RUD)-Lite instrument. A generalized linear model was fitted for association between cost of informal care and cognitive impairment, taking into account patient demographics, disease factors, and use of paid domestic help. Marginal estimates were obtained from the model for the purpose of illustration and discussion. Results: Total hours of informal care by primary caregiver doubled in moderate dementia patients, with 57.9% having paid domestic help to assist in care. Functional factors and use of paid domestic help were significantly associated with informal care costs. Costs were consistently higher for patients without paid domestic help for mild- and moderate dementia. Conclusion: This study demonstrates the informal care costs of caring for mild-moderate dementia patients in Singapore, with the unique cost savings provided by live-in paid domestic help, and potentially may aid policy-makers in allocation of resources and support to caregivers.
    International Psychogeriatrics 05/2013; 25(9):1-9. DOI:10.1017/S1041610213000707 · 1.89 Impact Factor
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    ABSTRACT: The Clinical Dementia Rating (CDR) scale is widely used to assess cognitive impairment in Alzheimer's disease. It requires collateral information from a reliable informant who is not available in many instances. We adapted the original CDR scale for use with elderly subjects without an informant (CDR-NI) and evaluated its reliability and validity for assessing mild cognitive impairment (MCI) and dementia among community-dwelling elderly subjects. At two consecutive visits 1 week apart, nurses trained in CDR assessment interviewed, observed and rated cognitive and functional performance according to a protocol in 90 elderly subjects with suboptimal cognitive performance [Mini-Mental State Examination (MMSE) <26 and/or Montreal Cognitive Assessment (MOCA) <26] and without informants according to a protocol. CDR domains and global scores were assigned after the second visit based upon corroborative information from the subjects' responses to questions, role-play, and observed performance in specifically assigned tasks at home and within the community. The CDR-NI scores (0, 0.5, 1) showed good internal consistency (Crohnbach's α 0.83-0.84), inter-rater reliability (κ 0.77-1.00 for six domains and 0.95 for global rating) and test-retest reliability (κ 0.75-1.00 for six domains and 0.80 for global rating), good agreement (κ 0.79) with the clinical assessment status of MCI (n = 37) and dementia (n = 4) and significant differences in the mean scores for MMSE, MOCA and Instrumental Activities of Daily Living (ANOVA global p < 0.001). Owing to the protocol of the interviews, assessments and structured observations gathered during the two visits, CDR-NI provides valid and reliable assessment of MCI and dementia in community-living elderly subjects without an informant.
    01/2013; 3(1):407-416. DOI:10.1159/000355122