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Gerontology Research Programme: The Singapore Longitudinal Ageing Studies (SLAS I & II) (SLAS)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03405675
Recruitment Status : Unknown
Verified March 2019 by A/Prof Ng Tze Pin, National University, Singapore.
Recruitment status was:  Active, not recruiting
First Posted : January 23, 2018
Last Update Posted : March 14, 2019
Karolinska Institutet
Tan Tock Seng Hospital
Ng Teng Fong General Hospital
St Luke's Hospital, Singapore
St. Paul's Hospital, Canada
Singapore Institute of Technology
Duke-NUS Graduate Medical School
Melbourne Health
University of California
University Hospital, Basel, Switzerland
Université de Sherbrooke
University Hospital Tuebingen
National University Hospital, Singapore
Khoo Teck Puat Hospital
Shanghai Jiao Tong University School of Medicine
University of British Columbia
Information provided by (Responsible Party):
A/Prof Ng Tze Pin, National University, Singapore

Brief Summary:
The Gerontology Research Programme (GRP) in the National University Singapore's Department of Psychological Medicine, was formed to coordinate and facilitate the conduct of multi-disciplinary research on in a wide range of research on ageing and health. The establishment of the Singapore Longitudinal Aging Cohort will provide a large community-based cohort of elderly subjects for observational studies with useful clinical applications. Research synergy is achieved in terms of pooling multi-disciplinary expertise, and combining genetic, biological, environmental, behavioural, social, clinical, and health services approaches to gerontological research.

Condition or disease Intervention/treatment
Cognitive Changes Due to Organic Disorder (Finding) Dementia Mild Cognitive Impairment Frailty Depression Healthy Ageing Biological Ageing Other: SLAS 1 Other: SLAS 2

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Study Type : Observational
Actual Enrollment : 6183 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Gerontology Research Programme: Biological, Clinical, Psychosocial and Behavioural Predictors of Health Status in Prospectively Followed-up Cohorts of Elderly Persons
Actual Study Start Date : July 1, 2003
Estimated Primary Completion Date : December 31, 2020
Estimated Study Completion Date : December 31, 2020

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
The subjects (N=2800) are recruited from all residents aged 55 years and above in Singapore in the areas covered by the South-East Community Development Council: Geylang, Aljunied, MacPherson, Marine Parade and Bedok (SLAS-I).
Other: SLAS 1
NA. Observational study, no interventions administered.

An additional 3200 subjects are recruited from residents in the Bukit Merah and Jurong (SLAS-II).
Other: SLAS 2
NA. Observational study, no interventions administered.

Primary Outcome Measures :
  1. Dementia and Mild Cognitive Impairment (MCI) Subtyping (Clinical diagnosis of different stages of Dementia) [ Time Frame: 20 years - once every 3-4 years ]
    Dementia and MCI is determined by clinical case conference adjudication where geriatric and psychiatric clinicians convene to determine the diagnosis of a case, utilizing the data from (i) Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) (4-5); (ii) Clinical Dementia rating scale: a 5-point scale used to characterize 6 cognitive and functional domain performance: Memory, Orientation, Judgment & Problem Solving, Community Affairs, Home & Hobbies, and Personal Care (6). Information to make each rating is obtained through a semi-structured interview of the patient and a reliable informant (e.g. family member). A higher score indicates increased severity of cognitive impairment; (iii) Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE) - reliable informants report on the cognitive state of the participant (7); (iv) a scale on self-reported subjective cognitive difficulties; and (v) a neuropsychological assessment battery (described below).

  2. Global and specific domain cognitive functioning ability (Measuring of Global and Specific domain of Cognitive functions) [ Time Frame: 20 years - once every 3-4 years ]

    MMSE (4) and MoCA (5) - 30 items, total scores range from 0-30, higher scores indicate better cognitive functioning. A cut-off of a score of =<25 is determined as screening positive for cognitive impairment.

    Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) (8) - measures immediate memory, visuospatial ability, language, attention, delayed memory, and a global cognitive functioning score (a summation of domain scores).

    A neurocognitive battery measures immediate and delayed memory/learning, visuospatial ability, language, attention, and executive functioning. All domains are calculated by weighted averages of age and education adjusted scores. Tests: (i) Digit Span forward and backwards tasks (9); (ii) Rey's Auditory Verbal Learning Test (10); (iii) Story Memory Test (11); (iv) Brief Visuospatial Memory Test - Revised (12); (v) Boston Naming Test (13); (vi) Clock Reading Test; (viii) Colour Trials 1 and 2 (14); (ix) Block Design task (9).

  3. Frailty (Measuring the physical and Cognitive Frailty) [ Time Frame: 20 years - once every 3-4 years ]
    Physical frailty was assessed by scores (1 = present, 0 = absent) for five components (shrinking, weakness, slowness, exhaustion, and low Physical Activity (PA)) proposed by Fried et al (3), with the following operational modifications: (i) Shrinking was defined by unintentional weight loss of 4 kg or more in the past 6 months, or BMI less than 18.5 kg/m2, or calf circumference of 31 cm or less. (ii) Weakness was assessed by knee extension strength task in kilogram. (iii) Slowness was assessed by a gait speed test (15). (iv) Exhaustion was measured as a summed score of 3 questions (1-5), "Did you have lots of energy/feel tired (reverse-scored, rs)/worn out (rs)?" (16). A score of <10 was used to denote exhaustion. (v) Low PA was measured by the LASA PA scale, with those falling below the local gender-specific lowest quintile deemed as low PA (17). Participants are categorised by their total scores as robust (score = 0), pre-frail (score = 1-2), and frail (score = 3-5).

  4. Depressive symptoms and diagnosis (Measuring of Depressive symptoms and assessment of stages of Depression) [ Time Frame: 20 years - once every 3-4 years ]
    Depressive symptoms are assessed by the 15-item version of the Geriatric Depression Scale (GDS), with a higher score indicating higher depressivity (18). A cut-off score of 5 is used as indicating the presence of depression. Additionally, participants are formally diagnosed by a medically trained research fellow for common mood-related psychiatric conditions using the Structured Clinical Interview for DSM Disorders (SCID) of DSM IV-TR (1), such as Major Depressive Disorder, Minor Depression, Dysthmic Disorder, Mania/Hypomania disorder, Anxiety and panic disorder, Obsessive-compulsive disorder, Post traumatic stress disorder, Psychotic disorder, Mood disorder due to a General Medical Condition and Alcohol abuse disorders, if they screen as positive for depression on the GDS.

  5. Successful ageing (Measuring the biological, psycho-social and lifestyle factors associated with Successful Ageing) [ Time Frame: 20 years - once every 3-4 years ]
    Successful aging is previously defined (25). Briefly, a score of successful ageing reflects the overall and physical health, cognitive, emotional, social well-functioning, including life engagement & satisfaction. Physical health and functional well-being was defined as a "good/excellent" self-reported health and IADL independence (20). Cognitive well-functioning and emotional wellbeing was denoted by a minimum MMSE score of 26 (4), and a score below 5 on the GDS (≤5) (18). Social functioning and active engagement in life activities was assessed using a validated questionnaire (26) on participation levels in social, recreational, civic activities, voluntary work, employment/business, and domestic activities. Overall positive life satisfaction was determined using the Life Satisfaction Scale that assessed interest in life, happiness, loneliness, and general ease of living (27). Total summed score ranges from 4 to 18, with the lowest decile indicating a positive life satisfaction.

Secondary Outcome Measures :
  1. Self-reported independent functioning (Measuring the BADL and IADL) [ Time Frame: 20 years - once every 3-4 years ]
    Self-reported Independent Functioning is assessed using the Barthel Index (19) and the Lawton and Brody Instrumental Activity of Daily Living Inventory (20), whereby participants report the degree of dependence on others for several daily and instrumental tasks.

  2. Physical performance (Measuring the physical performance tests) [ Time Frame: 20 years - once every 3-4 years ]
    Assessed by the Physical Performance Battery which includes the Performance-Oriented Mobility Assessment-Balance and Gait scales (21-22), with a higher score indicating a higher performance in terms of balance or gait; as well as the amount of force displaced in Newtons on a handgrip and knee extension dynamometer. The scores for each of the tests would be combined into a weighted average that reflects overall physical performance.

  3. Health services utilization (Measuring cost and frequency of health services utilization) [ Time Frame: 20 years - once every 3-4 years ]
    Self-reported frequency of doctor visits over a past 12-month period.

  4. Quality of life (Measuring the Quality of life SF 12) [ Time Frame: 20 years - once every 3-4 years ]
    Assessed by self-reported scales: (i) EQ5D- 3L - a measure of health-related quality of life that comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. The EQ VAS records the patient's self-rated health on a vertical visual analogue scale (23). (ii) 12-Item Short Form Survey (SF-12) is a 12-item questionnaire used to assess generic health outcomes from the patient's perspective, covering the eight domains of health outcomes: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional & mental health (24).

  5. Mortality (Measuring the risk factors related to mortality) [ Time Frame: 20 years ]
    Date and cause of death data is collected by computerized record linkage with the National Death Registry through the Singapore National Registry of Diseases Office (NRDO).

  6. Post-bronchodilation spirometry (Measuring the lung functions tests) [ Time Frame: 20 years - once every 3-4 years ]
    A measurement of lung function which yields the (i) Forced vital capacity - the determination of the vital capacity from a maximally forced expiratory effort; (ii) the FEV1 - volume that has been exhaled at the end of the first second of forced expiration; and the (iii) Peak expiratory flow: The highest forced expiratory flow measured with a peak flow meter. Measurements are made following American Thoracic Society (ATS) criteria for spirometric standardization and procedures, based on the best of four readings, with less than 5% variation in the two best readings. FEV1 is expressed as the percentage of predicted from local norms.

Biospecimen Retention:   Samples With DNA
Biological specimens (blood and urine) will be analyzed for full blood count, lipid panel, liver function test, blood biochemistry, PBMC, DNA, immunological tests (whole blood, serum, plasma).

Information from the National Library of Medicine

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Ages Eligible for Study:   55 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
Community-dwelling Elderly (>55 years old) that are able to self-ambulate and who possess sufficient cognitive capacity for participation. Individuals with severe physical or mental disabilities were excluded.

Inclusion Criteria:

  • Ability to self-ambulate
  • Adequate cognitive capacity for participation

Exclusion Criteria:

- Individuals with severe physical or mental disabilities were excluded.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03405675

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National University of Singapore
Singapore, Singapore, 119260
Sponsors and Collaborators
National University, Singapore
Karolinska Institutet
Tan Tock Seng Hospital
Ng Teng Fong General Hospital
St Luke's Hospital, Singapore
St. Paul's Hospital, Canada
Singapore Institute of Technology
Duke-NUS Graduate Medical School
Melbourne Health
University of California
University Hospital, Basel, Switzerland
Université de Sherbrooke
University Hospital Tuebingen
National University Hospital, Singapore
Khoo Teck Puat Hospital
Shanghai Jiao Tong University School of Medicine
University of British Columbia
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Principal Investigator: Tze Pin Ng, PhD National University, Singapore
American Psychiatric Association. Diagnostic and statistical manual of Mental Disorders, (4th ed., text rev.; DSM-IV-TR). American Psychiatric Association, Washington. 2000.
Folstein MF, Folstein SE, McHugh PR, Fanjiang G. Mini-Mental State Examination: MMSE user's guide. Psychology Assessment Resources; 2000.
Wechsler D. Wechsler adult intelligence scale-fourth. San Antonio, TX: The Psychological Corporation Google Scholar; 2008.
Rey A. L'examen psychologique dans les cas d'encéphalopathie traumatique.(Les problems.). Archives de psychologie (1941).
Yeo D, Gabriel C, Chen C, Lee S, Loenneker T, Wong M. Pilot validation of a customized neuropsychological battery in elderly Singaporeans. Neurol J South East Asia 1997 2(123).
Benedict RHB. Brief visuospatial memory test - revised: Professional manual. Lutz, FL: Psychological Assessment Resources, Inc; 1997.
Kaplan E, Goodglass H, Weintraub S. Boston naming test. Pro-ed; 2001.
D'Elia LF, Satz P, Uchiyama CL, White T. Color Trails Test: Professional Manual. Odessa (Florida): Psychological Assessment Resources; 1996.
Ware JE, Keller SD, Kosinski M. SF-12: How to Score the SF-12 Physical and Mental Health Summary Scales. Lincoln, RI: QualityMetric; 1998.
Rabin R, Oemar M, Oppe M, Janssen B, Herdman M. EQ-5D-3L User Guide: Basic information on how to use the EQ-5D-3L instrument. Rotterdam: EuroQol Group; 2011.
Ware JE, Kolinski M, Keller SD. How to Score the SF-12 Physical and Mental Health Summaries: A User's Manual. Boston: The Health Institute, New England Medical Centre, Boston, MA; 1995.

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Responsible Party: A/Prof Ng Tze Pin, Associate Professorial Fellow and Research Director, National University, Singapore Identifier: NCT03405675    
Other Study ID Numbers: NUS-IRB 04-140
First Posted: January 23, 2018    Key Record Dates
Last Update Posted: March 14, 2019
Last Verified: March 2019

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by A/Prof Ng Tze Pin, National University, Singapore:
Mild cognitive impairment
Cognitive abilities and changes
Functional change and disabilities
Health and social services utilization
Quality of life
Adverse drug effects
Social network and support
Self-rated health
Medical morbidities
Health risk behaviors
Apo-E lipoprotein
Physical activity
Leisure activity
Successful ageing
Additional relevant MeSH terms:
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Cognitive Dysfunction
Behavioral Symptoms
Mental Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Neurocognitive Disorders
Cognition Disorders
Pathologic Processes