22
Measuring Cognitive Status in Older Age 1 SAGE Working Paper No. 3. November 2012. Measuring cognitive status in older age in lower income countries: Results from a pilot of the Study on global AGEing and Adult Health (SAGE). Brionne Alvord Carroll 1 , Paul Kowal 2 , Nirmala Naidoo 2 , Somnath Chatterji 2 1 Department of Pharmacy Practice, University of Washington, Seattle, Washington, USA. 2 Department of Measurement and Health Information Systems, World Health Organization, Geneva, Switzerland. …. Corresponding author: Dr Paul Kowal co-PI SAGE World Health Organization Department of Health Statistics and Information Systems 20 Avenue Appia CH-1211 Geneva 27 Switzerland Acknowledgements: We would like to thank Kathleen Brodrick, Federico Campigotto, Monica Ferreira, Barry Gurland, Sebastiana Kalula and Nadia Minicuci for their assistance in assessing and measuring cognition across countries and cultures. SAGE is supported by the Division of Behavioral and Social Research of the US National Institute on Aging through Interagency Agreements (OGHA 04034785; YA1323-08-CN-0020; Y1-AG-1005-01) with the World Health Organization. Word Count (text only): 2233

SAGE Working Paper No. 3. November 2012. Measuring ......Measuring Cognitive Status in Older Age 1 SAGE Working Paper No. 3. November 2012. Measuring cognitive status in older age

  • Upload
    others

  • View
    2

  • Download
    0

Embed Size (px)

Citation preview

  • Measuring Cognitive Status in Older Age

    1

    SAGE Working Paper No. 3. November 2012.

    Measuring cognitive status in older age in lower income countries: Results from

    a pilot of the Study on global AGEing and Adult Health (SAGE).

    Brionne Alvord Carroll1, Paul Kowal2, Nirmala Naidoo2, Somnath Chatterji2 1 Department of Pharmacy Practice, University of Washington, Seattle, Washington, USA. 2 Department of Measurement and Health Information Systems, World Health Organization, Geneva, Switzerland. …. Corresponding author: Dr Paul Kowal co-PI SAGE World Health Organization Department of Health Statistics and Information Systems 20 Avenue Appia CH-1211 Geneva 27 Switzerland

    Acknowledgements:

    We would like to thank Kathleen Brodrick, Federico Campigotto, Monica Ferreira, Barry

    Gurland, Sebastiana Kalula and Nadia Minicuci for their assistance in assessing and

    measuring cognition across countries and cultures. SAGE is supported by the Division

    of Behavioral and Social Research of the US National Institute on Aging through

    Interagency Agreements (OGHA 04034785; YA1323-08-CN-0020; Y1-AG-1005-01)

    with the World Health Organization.

    Word Count (text only): 2233

  • Measuring Cognitive Status in Older Age

    2

    Word Count (abstract): 232

    Tables & Figures: 4 tables, 2 figures (if possible); otherwise 2 figures in the Appendix 1

    Appendices: 4

  • Measuring Cognitive Status in Older Age

    3

    Abstract

    Background. A reliable tool to measure cognition in older persons as part of

    household health surveys is needed: in particular, a culture-fair instrument to distinguish

    track decline in cognitive function. Additionally, the instrument should be sensitive to

    different literacy levels. Currently available tools used to screen for cognitive decline

    show substantial variation across different countries, suggesting limitations in accuracy

    and reliability.

    Methods. Implementing a battery of cognitive tests, verbal fluency, immediate and

    delayed verbal recall and digit-span forward and backward, in a household health

    survey pilot from the World Health Organization Study on AGEing and adult health

    (SAGE) in Ghana, India, and Tanzania. The survey included self-reported health with

    anchoring vignettes, plus self-reported and measured function.

    Results. A total of 1446 respondents completed the study. Self-reported health differed

    by age, sex and education. Verbal recall scores varied slightly by country and sex, with

    women consistently scoring lower than men. Lower scores were also associated with

    increasing age. The influence of sex was more pronounced in verbal fluency and less

    impacted by age. Results varied on digit span by education. Higher education levels

    positively impacted scores on all cognitive tests.

    Conclusions. The SAGE survey proved to be a culture-sensitive screening tool in a

    diverse set of countries. The instruments had face validity in all countries and were

    sensitive to age, sex and education levels. This approach can be used for the

    assessment of cognition in older age.

  • Measuring Cognitive Status in Older Age

    4

  • Measuring Cognitive Status in Older Age

    5

    Introduction

    Assessing cognition is a complex task even in a relatively homogenous population, but

    measuring age-related cognitive decline across countries and in the context of an

    ageing world presents significant challenges. With the expected ageing of populations

    across the globe over the next 25 years, countries will be faced with larger older

    populations, many experiencing cognitive changes. The established association

    between increasing age and dementia rates could therefore lead to increased mental

    health disease burdens. Dementia, one possible outcome from cognitive change, will

    increasingly occur in low and middle income countries as a result of population aging1.

    Mild cognitive impairment is often used to define those who might be at risk of

    developing dementia and may be a target for early interventions; consequently,

    measuring cognition to establish rates and trends would be useful2,3.

    Older adults may experience changes in their abilities to name objects or with their

    visual, verbal and short-term memory - some of which may be considered a normal

    consequence of the ageing process.4,5,6 When these cognitive changes begin impacting

    daily functioning or quality of life, the ability to accurately and reliably measure and

    differentiate normal changes from disease processes becomes more important for

    planning purposes.7,8,9

    In recent years, research on cognition has improved the understanding of cognitive

    impairment and progression to dementia.3,10 Estimates of cognitive impairment vary by

    up to 25% within a given country, depending on the selected definition of

  • Measuring Cognitive Status in Older Age

    6

    impairment.11,12 Adding a measure of function in the form of Instrumental Activities of

    Daily Living (IADL), has been shown to improve the accuracy of cognitive assessments

    even in populations with different education levels and socioeconomic status. 13 , 14

    Lower cognition scores correlated with greater impairments in functioning, suggesting

    IADL improves assessment of cognitive decline. 15 Similar to measuring cognitive

    impairment rates, rates of various dementias differ between countries, even when using

    consistent diagnostic definitions. 16 These discrepancies highlight the difficulty in

    ascertaining true cognition levels with existing tools, and differentiating between

    "normal" cognitive decline and decline preceding the onset of dementia.

    A reliable tool to measure cognition in older persons as part of household health

    surveys is needed: in particular, a culture-fair instrument to distinguish normal cognition

    from pathological decline.17,18,19 Additionally, the instrument should be sensitive to

    different literacy levels. Currently available tools used to screen for cognitive decline

    show substantial variation across different countries, suggesting limitations in accuracy

    and reliability.20,21,22, 23

    The battery of tests in this study originated from the World Health Organization's World

    Health Survey (WHS) programme, which has used self-reported and measured

    cognition in over 70 countries.24 The three cognitive tests selected as part of the Study

    on AGEing and adult health's (SAGE) pilot test - word list recall, verbal fluency and digit

    span - accurately measure the cognitive domains most impacted by age, impairment

    and the early stages of dementia. The selected tasks are also brief compared to other

  • Measuring Cognitive Status in Older Age

    7

    neuropsychological tests, allowing for a culture-fair screening tool within a household

    health survey that combines subjective and objective measures of cognition and

    physical function. Lastly, it can be implemented by trained lay interviewers.8 We

    present the initial results from a pilot study of the World Health Organization's SAGE

    instrument.

    Methods

    The SAGE survey was piloted in Ghana, India and Tanzania from April to July 2005.

    Face-to-face interviews were conducted in respondent's dwellings. Translation and

    back-translation methods based on the WHS protocol were used (WHO, 2003). Data

    collected included household and housing characteristics, income, expenditures and

    transfers, self-reported health in 12 domains, and measured cognitive and physical

    function.

    India and Ghana used a convenience sample to obtain the desired sample size of

    N=500 persons aged 50 years and older, with an emphasis on enlisting similar numbers

    of men and women across the older age ranges. Respondents in Tanzania were

    randomly selected from household listings within a demographic surveillance site in the

    north-eastern region of the country. India included a small sample of respondents

    younger than 50 years as a comparator group. Training sessions for survey

    methodologies and instruments were provided in each country.

  • Measuring Cognitive Status in Older Age

    8

    Self-reported cognition was assessed through two questions, one about concentration

    and the other about learning. In addition, measures of functioning - were assessed

    through the WHO Disability Assessment Scale, Version 2.0 (WHODAS) along with

    additional questions about Activities of Daily Living (ADLs) and Instrumental Activities of

    Daily Living (IADL).25

    Performance tests:

    Three domains were selected to objectively measure cognition: assessment of memory

    and learning (using the word-list learning task); working memory (using digit span

    forward and backward); and, verbal fluency (using the category fluency test).26,27,28 All

    three performance tests were scored according to standard practices for each test.

    Verbal recall, measured with a 10-word learning task, was estimated by summing the

    four trials, three immediate recall and one delayed by 10 to 15 minutes.2612 Scoring for

    digit span forward and backward involved tabulations based on first or second try

    correct recitation of each number series - two points or one point per row, with eight

    rows in total for each of the two tests. The final task, verbal fluency, was measured as

    the sum of all admissible words regarding the category of animals. STATA version 9.2

    was used for all analyses.

    Results

    A total of 1446 respondents completed the survey. Fifty-four percent of respondents

    were women (see Table 1). The mean age was 59 years in India, 61 years in Ghana

    and 65 years in Tanzania. The sample in Ghana was primarily urban, Tanzania

  • Measuring Cognitive Status in Older Age

    9

    primarily rural and the India sample a mixture between rural and urban. It was possible

    in Ghana to collect follow-up data on 119 respondents from the baseline World Health

    Survey conducted in 2003. Levels of education varied by country, but women

    consistently had lower levels of education than men across all countries.

    [Table 1 about here]

    The pattern of self-reported cognition, memory and learning, were significantly different

    by sex and age (p

  • Measuring Cognitive Status in Older Age

    10

    [Table 2 about here: Mean VR, VF scores by country, sex, age and education level]

    Verbal fluency results were comparable in Ghana, India, and Tanzania: the mean

    number of animals named in one minute was 10.8, 11.5 and 9.5, respectively. The

    influence of sex was more pronounced in verbal fluency than verbal recall, with larger

    differences between mean scores of women and men than with verbal recall. Verbal

    fluency was less influenced by age until respondents reached the 80 year and older

    group. Mean verbal fluency scores increased with higher levels of education. Each

    additional year of education completed resulted in almost one additional animal named

    (0.928, p < 0.001). Respondents in India, for example, who completed college degrees

    or further education named a third more animals than those with no formal education.

    The third performance test included reciting a digit-span forward and backward. In each

    country, fewer respondents completed this task in comparison to the other performance

    tests. Tanzanian respondents consistently scored lower in the forward and backward

    tests compared to the other countries (see Table 3). Respondents in Ghana scored 1.2

    points higher than those in India for digits forward, while mean scores in India were 2.4

    points higher than in Ghana for digits backward. The influence of sex and age were

    inconsistent across countries for digit span. As with the previous two tests, higher

    educational levels resulted in higher mean scores.

    [Table 3 about here]

  • Measuring Cognitive Status in Older Age

    11

    Since cognitive function is an intrinsic component of ADLs,158 we included WHODAS to

    measure function associated with cognition, plus additional ADL/IADL type questions.

    The WHODAS contains many of the most commonly asked ADL and IADL questions -

    plus the WHODAS approach also assesses severity of disability. Tanzanians reported

    less disability than either Ghana or India. Forty percent of the respondents in

    Tanzania reported no problems with ADLs (see Table 4), and correspondingly had the

    lowest disability assessment score of 18.5. Comparatively, between 26 and 28% of

    respondents in Ghana and India stated no difficulties with ADLs.

    Across all three countries, substantially more women reported problems with

    ADL/IADLs. In Ghana, 51% of women reported difficulties in at least two activities of

    daily living compared to 35% of men. Additionally, women had higher mean WHODAS

    scores, with even a third higher score in India than for men. Older age groups reported

    higher WHODAS scores. Seventy-one percent of respondents in India, ages 18-49 had

    no difficulty with ADLs compared to 25% at the ages 50-59, and almost 12% in

    respondents aged 80 years and older. Those with less education, particularly no formal

    education, reported substantially more disability than the respondents who had at

    minimum completed high school or the equivalent. In Tanzania, mean WHODAS

    scores declined from 22.9 in respondents with no formal education, to 5.6 in

    respondents who have completed college or university.

    [Table 4 about here]

  • Measuring Cognitive Status in Older Age

    12

    As an objective measure of mobility, the mean time to complete a 4 meter walk at usual

    pace was longest in Ghana at 6.2 seconds, followed by Tanzania at 5.8 seconds and

    4.5 seconds in India. Mean times were longer for women in each country, and

    increased with increasing age. The differences in mobility as measured by the timed

    walk and WHODAS scores across countries reflect the multidimensionality of the

    WHODAS tool and both followed recognizable age and sex trends.

    Discussion

    Currently, an estimated 24 million persons worldwide live with dementia, a number

    expected to reach 81 million by 2040. 29 Accurately measuring cognition and

    determining global prevalence of dementia will continue to be a problem due to the

    inconsistency of available data across countries. Previous attempts to reconcile

    differences in cross-cultural observations of dementia found that less than half of

    dementia cases across countries were consistently diagnosed correctly.30 Even among

    developed regions with sound epidemiological studies, a large proportion of variability

    exists in reported dementia rates. 31 , 32 Yet it is in developing countries where the

    majority of persons with dementia reside, but where little is known about prevalence.

    An estimated 60% of those with dementia currently live in developing countries and this

    is projected to climb to nearly three-fourths of the population with dementia by 2040.2915

    Attempting to measure cognition within a household health survey requires additional

    considerations in regards to interview time, complexity and selection of cognition

  • Measuring Cognitive Status in Older Age

    13

    domains. Mild cognitive impairment and early stages of dementia particularly impact

    memory, attention, learning, and language. 33 , 34 Episodic, semantic, and working

    memory decline early in disease progression.35,36 Testing these elements of memory

    may therefore be ideal for screening patients for dementia prior to diagnosis.

    Another challenge is the reliability and comparability of answers to questions that use

    ordered categorical response scales like those used for self-reported cognition.37 One

    method to address this comparability problem is the anchoring vignettes approach.38

    The vignettes use a concrete level of cognition and respondents are asked to rate the

    vignettes using the same questions and response categories that they use to describe

    their own cognition. Vignettes fix the level of cognitive ability so that variation in

    categorical responses is attributable to variation in response category cutpoints.

    Objective cognition tests are employed as one step to establish the validity this

    methodology. Vignette adjusted results for this SAGE pilot will be presented elsewhere.

    The verbal recall word-list test involves short- and long-term memory, plus learning a

    new task.2612 This verbal recall test, along with a verbal fluency test, rank among the

    best discriminating tests for cognitive impairment and the most sensitive for patients

    with Alzheimer's disease.3521, 3622, 39 Verbal fluency tests both language and semantic

    memory. Cognitive impairment impacts category fluency over letter fluency.40 Among

    categories, animal fluency performs as a better marker for dementia than listing words

    beginning with a certain letter.41 Category fluency maintains as high as 100% sensitivity

    for dementia.42 Digit span, the third in our battery of tests, assesses short-term and

  • Measuring Cognitive Status in Older Age

    14

    working memory as well as attention and concentration with a high degree of

    reliability.2713, 3622 Cognitively impaired patients scored lower than normal respondents,

    particularly on the reverse span.43

    The results of this study across the three countries indicated strong face validity for the

    self-reported questions and performance tests. Women, persons of older age, and

    those with less education scored lower on both the self-reported and administered

    cognitive tests. These results support the battery of tests presented in this study as a

    culture-fair measure of cognition as well as a comprehensive tool in its assessment of

    both self-report and performance-based measures of function. One recognized

    limitation was initiating the digit span performance task with too complex a series,

    evidenced in the results by the small number of respondents able to complete even the

    first row correctly. This task has been altered in the recent survey to a series of three

    digits for digit forward and two digits for digit backwards to facilitate greater accuracy.

    This pilot data covered relatively smaller populations from three different countries.

    These pilot results has informed the implementation of the full survey and further

    develop a culture-fair cognitive screening tool for use in household health surveys.

    Data from an anticipated six countries will help to improve the assessment of cognition

    worldwide.

  • Measuring Cognitive Status in Older Age

    15

    TABLES AND FIGURE

    Table 1. Sociodemographic characteristics by sex and country.

    Ghana India Tanzania

    Male Female Total Male Female Total Male Female Total

    Age

    18-49 na* na na 14.8 6 10.4 na na na

    50-59 50.9 44.1 47.2 32.2 37.3 34.8 40.9 37.5 39.0

    60-69 24.8 30.4 27.9 34.7 30.5 32.6 28.8 35.1 32.4

    70-79 16.4 17.1 16.8 16.1 20.6 18.3 20 15.4 17.4

    80+ 6.5 6.5 6.5 2.1 5.2 3.6 10.2 11.9 11.2

    Missing 1.4 1.9 1.7 0 0.4 0.2 0 0 0

    Residence

    Urban 90.7 89.4 89.9 53.8 54.9 54.4 1.4 0.7 1.0

    Rural 9.3 10.6 10.1 46.2 45.1 45.6 98.6 99.3 99.0

    Marital Status

    Never 2.3 0.4 1.3 5.5 0.4 3 0.5 0 0.2

    Currently 79.0 36.5 55.6 87.7 58.8 73.4 80.5 28.8 51.0

    Separated/Divorced 7.9 25.1 17.4 0 1.3 0.6 8.8 22.5 16.6

    Widowed 10.3 37.6 25.4 6.8 39.1 22.8 10.2 47.0 31.2

    Co-habiting 0 0.4 0.2 0 0 0 0 1.8 1.0

    Missing 0.5 0 0.2 0 0.4 0.2 0 0 0

    Education No formal education 17.3 49.4 35 31.8 71.2 51.4 33.5 80.7 60.4

    Less than Primary 9.3 12.5 11.1 14.4 4.7 9.6 37.2 14.4 24.2

    Primary 32.2 24.3 27.9 19.1 11.6 15.4 23.3 4.6 12.6

    Secondary 20.6 8.0 13.6 11.9 4.3 8.1 4.7 0 2.0

    High School 12.1 4.6 8.0 8.1 2.1 5.1 0 0.4 0.2

    College/University 6.1 1.1 3.4 8.9 4.7 6.8 1.4 0 0.6

    Post Graduate 1.9 0 0.8 5.9 0.9 3.4 0 0 0

    Missing 0.5 0 0.2 0 0.4 0.2 0 0 0

    Income quintile

    1 (lowest) 13.6 24.0 19.3 20.3 17.2 18.8 8.8 28.1 19.8

    2 19.6 18.3 18.9 17.8 19.7 18.8 19.1 20.4 19.8

    3 21.5 17.5 19.3 14.4 23.2 18.8 19.1 20.7 20.0

    4 20.1 18.6 19.3 20.3 20.2 20.3 23.7 17.2 20.0

    5 (highest) 22.9 16.0 19.1 25.4 19.3 22.4 28.4 13.0 19.6

    Missing 2.3 5.7 4.2 1.7 0.4 1.1 0.9 0.7 0.8

    Total 100 100 100 100 100 100 100 100 100

    Number 214 263 477 236 233 469 215 285 500

    *na = not applicable

  • Measuring Cognitive Status in Older Age

    16

    Table 2. Mean verbal recall (VR), verbal fluency (VF) scores by country, sex, age and education level.*

    Ghana India Tanzania

    VR VF VR VF VR VF

    Sex

    Male 21.2 11.7 19.1 12.6 19.2 11.2

    Female 20.2 10.2 17.5 10.3 19.1 8.2

    Total 20.6 10.8 18.3 11.4 19.2 9.5

    Age group

    18-49 23.7 14

    50-59 21.8 11.4 19.4 11.7 20.2 9.9

    60-69 20.9 10.8 17.6 11.3 19.1 9.5

    70-79 19.1 10.4 15.6 10.1 19 9.4

    80+ 15 8.7 13.7 9.5 16 8.1

    Total 20.7 10.9 18.4 11.4 19.2 9.5

    Education

    No formal 19.7 9.9 16.0 9.9 18.8 8.6

    Less than primary 19.1 10.8 19.2 11.8 20.1 10.6

    Primary completed 20.6 10.8 20.2 12.8 18.5 11.1

    Secondary completed 21.7 12.2 20.7 12.3 22.2 12.9

    High school 22.7 11.7 20 12.8 25 1

    College/university completed 24.3 12.6 24.1 15.6 14 11

    Post-graduate degree completed 29.3 13.5 22.8 15.3 Total 20.7 10.8 18.4 11.4 19.2 9.5

    *See Appendix 2 for the word-list (VR) and category fluency (VF) performance tests.

  • Measuring Cognitive Status in Older Age

    17

    Table 3. Number (N) of respondents completing the digit span tests and mean scores for forward (DF) and backward (DB) by country, sex, age and education level.* Ghana India Tanzania

    DF DB DF DB DF DB

    N Mean N Mean N Mean N Mean N Mean N Mean

    Sex

    Male 182 3.9 63 2.3 39 2.4 11 3.6 68 1.5 17 1.4

    Female 174 3.0 56 2.7 16 2.3 3 9.7 43 1.7 14 2.4

    Total 356 3.5 119 2.5 55 2.3 14 4.9 111 1.6 31 1.8

    Age group

    18-49 0 0 0 0 16 2.3 7 3.3 0 0 0 0

    50-59 186 3.8 67 2.5 19 2.5 1 13 58 1.6 16 1.4

    60-69 99 3.4 34 2.7 16 2.1 2 2 36 1.6 10 2.7

    70-79 48 3.0 12 2.2 4 3.0 4 7.3 15 1.5 5 1.4

    80+ 18 2.3 1 1.0 0 0 0 0 2 1.5 0 0

    Total 351 3.5 114 2.5 55 2.3 14 4.9 111 1.6 31 1.8

    Education

    No formal 84 2.1 23 2.7 6 1.7 2 8.5 36 1.3 7 2.7

    Less than 38 2.8 14 2.4 4 1.5 1 8 36 1.6 11 1.4

    Primary 113 3.6 30 2.3 7 2.1 0 0 29 1.7 9 1.9

    Secondary 64 4.6 30 2.7 7 2.9 2 7 8 1.8 2 1

    High school 37 4.5 13 1.8 4 2.5 1 2 1 7 1 3

    College/university

    completed

    16 4.3 6 3.2 19 2.4 3 1.7 1 1 1 1

    Post-graduate

    degree

    4 5.3 3 2.7 8 2.8 5 4.6 0 0 0 0

    Total 356 3.5 119 2.5 55 2.3 14 4.9 111 1.6 31 1.8

    *See Appendix 2 for the digit span forward and backward performance tests.

  • Measuring Cognitive Status in Older Age

    18

    Table 4. ADL deficiencies (%) and mean WHODAS score by country, sex, age and education level.* Ghana India Tanzania

    ADL Mean

    DAS

    ADL MeanDA

    S

    ADL MeanDA

    S Non

    e One

    2+ Non

    e One

    2+ Non

    e One

    2+

    Sex

    Male 38.3

    26.6

    35 17.8 37.7 22.

    5 39.

    8 17 51.2

    23.3

    25.6

    12.5

    Female 16

    33.1

    51 27.4 18.5 20.

    2 61.

    4 29.3 32.6

    24.6

    42.8

    23.1

    Total 26

    30.2

    43.8

    23.1 28.1 21.

    3 50.

    5 23.1 40.6 24

    35.4

    18.5

    Age group

    18-49 0 0 0 0 71.4

    12.2

    16.3

    8.7 0 0 0 0

    50-59 35.1 32

    32.9

    15.9 25.2 27 47.

    9 20.2 57.4 20

    22.6

    11.7

    60-69 24.1

    28.6

    47.4

    24.7 27.5 22.

    2 50.

    3 23 38.3 29

    32.7

    18

    70-79 10

    31.3

    58.8

    33 12.8 17.

    4 69.

    8 33.1 19.5

    29.9

    50.6

    26.7

    80+ 0

    25.8

    74.2

    45.3 11.8 5.9 82.

    4 45.1 21.4

    14.3

    64.3

    31

    Total 26

    30.2

    43.8

    23.3 28.1 21.

    3 50.

    5 23.2 40.6 24

    35.4

    18.5

    Education

    No formal 14.4

    40.1

    45.5

    26.9 19.5 17.

    8 62.

    7 30.1 32.8

    23.8

    43.4

    22.9

    Less than primary

    18.9 28.

    3 52.

    8 28.5 31.1 20

    48.9

    18.3 47.9 28.

    1 24 12.9

    Primary completed

    33.1 26.

    3 40.

    6 22.2 27.8

    30.6

    41.7

    18.1 54 20.

    6 25.

    4 11.1

    Secondary completed

    26.2 23.

    1 50.

    8 19.5 34.2

    31.6

    34.2

    18 80 10 10 6.1

    High school completed

    39.5 23.

    7 36.

    8 16.4 50 25 25 12.4 100 0 0 8.3

    College/university completed 56.3

    18.8 25 11.6 46.9

    15.6

    37.5 10.8 100 0 0 5.6

    Post-graduate degree completed 100 0 0 1.4 62.5

    18.8

    18.8 9 0 0 0 0

    Total 26

    30.2

    43.8

    23.2 28.1 21.

    3 50.

    5 23.2 40.6 24

    35.4

    18.5

    Response scale: 1=none; 2=mild; 3=moderate; 4=severe; 5=extreme/cannot do.

    *See Appendices 3 and 4 for the WHODAS and ADL-scale specific questions.

  • Measuring Cognitive Status in Older Age

    19

    APPENDIX 1. Self-reported Health

    Figure 1. Self reported memory by age and sex ("Overall in the last 30 days, how much difficulty did you have with concentrating or remembering things?").

    0%

    10%

    20%

    30%

    40%

    50%

    60%

    70%

    80%

    90%

    100%

    M,18-49 M,50-59 M,60-69 M,70-79 M,80+ F, 18-49 F,50-59 F,60-69 F,70-79 F,80+

    None Mild Moderate Severe Extreme

    Figure 2. Self reported learning by age and sex ("Overall in the last 30 days, how much difficulty did you have in learning a new task (for example, learning how to get to a new place, learning a new game, learning a new recipe)?").

    0%

    10%

    20%

    30%

    40%

    50%

    60%

    70%

    80%

    90%

    100%

    M,18-49 M,50-59 M,60-69 M,70-79 M,80+ F, 18-49 F,50-59 F,60-69 F,70-79 F,80+

    None Mild Moderate Severe Extreme

  • Measuring Cognitive Status in Older Age

    20

    APPENDIX 2. Cognitive tests used in SAGE

    WORD-LIST RECALL (maximum 40 points) List of words used Arm, Bed, Plane, Dog, Clock, Bike, Ear , Hammer, Chair, Cat Immediate Recall plus learning saturation Number of words recalled correctly Trial 1, 2, 3 Number of words that respondent failed to recall Trial 1, 2, 3 Number of words substituted Trial 1, 2, 3 Delayed Recall Number of words recalled correctly Number of words that respondent failed to recall Number of words substituted

    DIGIT SPAN (maximum 16 points for forward and 16 points for backward)

    Points Sequence of numbers 0, 1,2 4-7-2-8-1

    3-4 8-4-7-2-5-1

    5-6 3-9-0-7-1-8-2 7-8 2-6-8-9-0-4-1-5

    9-10 8-5-7-3-2-0-1-5-9

    11-12 9-6-7-3-9-5-1-6-3-8

    13-14 5-1-6-8-9-3-2-0-8-3-1

    15-16 3-7-2-9-1-0-5-2-6-4-3-8

    CATEGORY FLUENCY

    Number of animals named correctly in one minute. Number of errors.

    APPENDIX 3. WHO Disability Assessment Scale (WHODAS-12 item)

    In the last 30 days, how much difficulty did you have …*

    1 … in standing for long periods (such as 30 minutes)?

    2 … in taking care of your household responsibilities?

    3 … in learning a new task, for example, learning how to get to a new place?

    4 … in joining in community activities (for example, festivities, religious or other activities) in the same way as anyone else can?

    5 … concentrating on doing something for 10 minutes?

    6 … in walking a long distance such as a kilometer (or equivalent)?

    7 … in washing your whole body?

    8 … in getting dressed (including, for example, putting on your shoes and socks)?

    9 … with people you do not know?

    10 … in maintaining a friendship?

    11 … in your day to day work?

    12 In the last 30 days, how much have you been emotionally affected by your health condition(s)?

    *Response scale: 1=none; 2=mild; 3=moderate; 4=severe; 5=extreme/cannot do.

  • Measuring Cognitive Status in Older Age

    21

    APPENDIX 4. Activities of Daily Living Scale

    In the last 30 days, how much difficulty did you have …*

    1 …in standing up from sitting down (such as, getting up from a chair after sitting for long periods)?

    2 … in washing your whole body?

    3 …in getting dressed (including, for example, putting on your shoes and socks)?

    4 … with moving around inside your home (such as walking across a room)?

    5 … with eating (including cutting up your food)?

    6 … with getting up from lying down (for example, getting in and out of bed)?

    7 … with getting to and using the toilet?

    *Response scale: 1=none; 2=mild; 3=moderate; 4=severe; 5=extreme/cannot do.

    References

    1 Ferri CP, Prince M, Brayne C, Brodaty H, et al. Global prevalence of dementia: a Delphi consensus study. Lancet.

    2005;366:2112–7. 2 Sosa AL, Albanese E, Stephan BCM, Dewey M, et al. Prevalence, distribution, and impact of mild cognitive

    impairment in Latin America, China and India: A 10/66 population-based study. PLoS Med. 2012:9(2):e1001170. 3 Alzheimer’s Disease International. World Alzheimer Report 2011. The benefits of early diagnosis and intervention.

    London: Alzeheimer’s Disease International. 2011. www.alz.co.uk/research/WorldAlzheimerReport2011.pdf 4 Levy R. Aging-associated cognitive decline. Working party of the International Psychogeriatric Association in

    collaboration with the World Health Organization. Int Psychogeriatr. 1994;6(1):63–8 [review]. 5 Smith GE, Petersen RC, Parisi JE, et al. Definition, course, and outcome of mild cognitive impairment. Aging

    Neuropsychol Cogn. 1996;3:141–7. 6 Craik FIM, Salthouse TA (Eds.). Handbook of aging and cognition. Hillsdale, NJ: Lawrence Erlbaum Associates,

    1992. 7 Unverzagt FW, Ogunniyi A, Taler V, Gao S, et al. Incidence and risk factors for cognitive impairment no dementia

    and mild cognitive impairment in African Americans. Alzheimer Dis Assoc Disord, 25(1):4-10, 2011, PM:20921881. 8 Prince M, Acosta D, Ferri CP, Guerra M, et al. A brief dementia screener suitable for use by non-specialists in

    resource poor settings - the cross-cultural derivation and validation of the brief Community Screening Instrument for

    Dementia. Int J Geriatr Psychiatry. 2011;26(9):899-907.. 9 Ogunniyi A, Lane KA, Baiyewu O, Gao S, Gureje O, Unverzagt FW, Murrell JR, Smith-Gamble V, Hall KS,

    Hendrie HC. Hypertension and incident dementia in community-dwelling elderly Yoruba Nigerians. Acta Neurol

    Scand. 2011;124(6):396-402. 10

    Unverzagt FW, Gao S, Baiyewu O, et al. Prevalence of cognitive impairment: data from the Indianapolis study of

    health and aging. Neurology. 2001;57:1655-62 11

    Meguro K, Ishii H, Yamaguchi S, et al. Prevalence and cognitive performance of clinical dementia rating 0.5 and

    mild cognitive impairment in Japan. The Tajiri project. Alzheimer Dis Assoc Disord. 2004;18(1):3-10. 12

    Pioggiosi PP, Berardi D, Ferrari B, Quartesan R, De Ronchi D. Occurrence of cognitive impairment after age 90:

    MCI and other broadly used concepts. Brain Res Bull. 2006;68(4):227-32. 13

    Mathuranath PS, George A, Cherian PJ, Mathew R, Sarma PS. Instrumental activities of daily living scale for

    dementia screening in elderly people. Int Psychogeriatr. 2005;17(3):461-74. 14

    Bruffaerts R, Vilagut G, Demyttenaere K, Alonso J, et al. Role of common mental and physical disorders in

    partial disability around the world. Br J Psychiatry. 2012 Apr 26. [Epub ahead of print] 15

    Ishizaki T, Yoshida H, Suzuki T, et al. Effects of cognitive function on functional decline among community-

    dwelling non-disabled older Japanese. Arch Gerontol Geriatr. 2006;42(1):47-58. 16

    Xu G, Meyer JS, Huang Y, Chen G, Chowdhury M, Quach M. Cross-cultural comparison of mild cognitive

    impairment between China and the USA. Curr Alzheimer Res. 2004;1(1):55-61. 17

    Xu G, Meyer JS, Huang Y, Chen G, et al. Cross-cultural comparison of mild cognitive impairment between China

    and USA. Curr Alzheimer Res 2004;1: 55–61.

  • Measuring Cognitive Status in Older Age

    22

    18

    Arnaiz E, Almkvist O, Ivnik RJ, Tangalos EG, et al. Mild cognitive impairment: a cross-national comparison. J

    Neurol Neurosurg Psych 2004;75:1275–80. 19

    Baiyewu O, Unverzagt FW, Ogunniyi A, Smith-Gamble V, et al. Behavioral symptoms in community-dwelling

    elderly Nigerians with dementia, mild cognitive impairment, and normal cognition. Int J Geriatr Psychiatry.

    2012;Mar 2. doi: 10.1002/gps.2804. 20

    Stephan BC, Matthews FE, McKeith IG, Bond J, Brayne C. Early cognitive change in the general population: how

    do different definitions work? J Am Geriatr Soc 2007;55:1534–40. 21

    Palmer K, Backman L, Winblad B, Fratiglioni L. Detection of Alzheimer's disease and dementia in the preclinical

    phase: population based cohort study. BMJ 2003;326: 245. 22

    Panza F, Capurso C, D'Introno A, Colacicco AM, et al. Heterogeneity of mild cognitive impairment and other

    predementia syndromes in progression to dementia. Neurobiol Aging. 2007;28:1631-2. 23

    Sosa AL, Albanese E, Prince M, Acosta D, et al. Population normative data for the 10/66 Dementia Research

    Group cognitive test battery from Latin America, India and China: a cross-sectional survey. BMC Neurol. 2009;9:48. 24

    World Health Organization. World Health Survey. Geneva, Switzerland: World Health Organization, 2006.

    www.who.int/healthinfo/survey/whscurrent/en/ 25

    Ustün TB, Chatterji S, Kostanjsek N, Rehm J, et al. Developing the World Health Organization Disability

    Assessment Schedule 2.0. Bull World Health Organ. 2010;88:815-23. 26

    Spreen O, Strauss E. Memory. In: A Compendium of Neuropsychological Tests, 2nd ed. Oxford, England: Oxford

    University Press, 1998:260-422. 27

    Spreen O, Strauss E. General ability and premorbid intelligence. In: A Compendium of Neuropsychological Tests,

    2nd ed. Oxford, England: Oxford University Press, 1998:43-135. 28

    Spreen O, Strauss E. Language Tests. In: A Compendium of Neuropsychological Tests, 2nd ed. Oxford, England:

    Oxford University Press, 1998:423-480. 29

    Ferri CP, Prince M, Brayne C, et al. Global prevalence of dementia: a Delphi consensus study. Lancet.

    2005:366:2112-17. 30

    Gurland BJ, Wilder DE, Cross P, et al. Screening scales for dementia: toward reconciliation of conflicting cross-

    cultural findings. Int J Geriatr Psychiatry. 1992;7:105-113. 31

    Ott A, Breteler MM, van Harskamp F, Stijnen T, Hofman A. Incidence and risk of dementia. The Rotterdam

    Study. Am J Epidemiol. 1998;147(6):574-80. 32

    The Canadian Study of Health and Aging Working Group. The incidence of dementia in Canada. Neurology.

    2000;55:66-73. 33

    Blennow K, de Leon MF, Zetterberg H. Alzheimer's disease. Lancet. 2006; 368(9533):387-403 [review]. 34

    Jacobs DM, Sano M, Dooneief G, Marder K, Bell KL, Stern Y. Neuropsychological detection and

    characterization of preclinical Alzheimer's disease. Neurology. 1995;45(5):957-62. 35

    Spaan PE, Raaijmakers JG, Jonker C. Early assessment of dementia: the contribution of different memory

    components. Neuropsychology. 2005;19(5):629-40. 36

    Kalbe E, Kessler J, Calabrese P, et al. DemTect: a new, sensitive cognitive screening test to support the diagnosis

    of mild cognitive impairment and early dementia. Int J Geriatr Psychiatry. 2004;19(2):136-43. 37

    Salomon JA, Tandon A, Murray CJL. Comparability of self rated health: cross sectional multi-country survey

    using anchoring vignettes. BMJ. 2004;328(7434):258. 38

    Tandon A, Murray CJL, Salomon JA, King G. Statistical methods to enhance cross-population comparability. Global Programme on Evidence for Health Policy Discussion Paper No. 42. Geneva, Switzerland: World Health

    Organization, 2001. 39

    Petersen RC, Smith GE, Waring SC, Ivnik RJ, Tangalos EG, Kokmen E. Mild cognitive impairment: clinical

    characterization and outcome. Arch Neurol. 1999;56(3):303-8. 40

    Cerhan JH, Ivnik RJ, Smith GE, Tangalos EC, Petersen RC, Boeve BF. Diagnostic utility of letter fluency,

    category fluency, and fluency difference scores in Alzheimer's disease. Clin Neuropsychol. 2002;16(1):35-42. 41

    Canning SJ, Leach L, Stuss D, Ngo L, Black SF. Diagnostic utility of abbreviated fluency measures in Alzheimer

    disease and vascular dementia. Neurology. 2004;62(4):556-62. 42

    Monsch AU, Bondi MW, Butters N, Salmon DP, Katzman R, Thal LJ. Comparisons of verbal fluency tasks in the

    detection of dementia of the Alzheimer type. Arch Neurol. 1992;49(12):1253-8. 43

    Lam LC, Lui VW, Chiu HF, Chan SS, Tam CW. Executive function impairment in community elderly subjects

    with questionable dementia. Dement Geriatr Cogn Disord. 2005;19(2-3):86-90.