Cognition and activities of daily living in ageing and dementia Anthony Martyr April 2013

270 Pages·2013·5.54 MB·English

Cognition and activities of daily living in ageing and dementia

Anthony Martyr

Thesis submitted to the School of Psychology, Bangor University, in fulfilment
of the requirements for the degree of Doctor of Philosophy

April 2013
Declaration and Consent
Details of the Work
I hereby agree to deposit the following item in the digital repository maintained by
Bangor University and/or in any other repository authorized for use by Bangor
University.

Author Name: Anthony Martyr

Title: Cognition and activities of daily living in ageing and dementia

Supervisor/Department: Professor Linda Clare / School of Psychology

Funding body (if any): National Institute for Social Care and Health Research

Qualification/Degree obtained: Doctoral
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ii
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Signed ………………………………………….. (candidate)
Date 22/04/2013

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This thesis is the result of my own investigations, except where otherwise stated.
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Date 22/04/2013

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Date 22/04/2013

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iii
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Signature: ……………………………………………………… Date: 22/04/2013
iv
Acknowledgments

I would like to thank Linda Clare for her invaluable support and guidance that has
made the last six years a pleasure. I would also like to thank the research team, Aleks,
Carol, Cat, Catherine, Hannah, Julie, Lester, Lexi, Pam, and Sharon. Sharon especially
has been and is a good friend; her insightful comments and discussions have been
invaluable throughout the three years of the PhD. Aleks has been a great officemate
and was always there when I needed to deliberate a problem.

I am grateful to the memory clinic staff, particularly Bethan and Rhian, for their
assistance with recruiting participants. Not least, I am grateful for the time and
commitment given by all the participants who took part in the studies.

I would like to thank Ania for making the best cakes in existence. Jasna deserves
credit for being a constant support for the last ten years, always pushing me forward.
Tryfan has been a relaxing and motivating presence; some of my best ideas have been
thought while running up that mountain at seven o’clock in the morning. Finally,
Dajve made the solitude of writing up bearable.
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Table of contents

Declaration and consent .................................................................................. ii
Acknowledgments .............................................................................................v
Table of contents ............................................................................................. vi
List of tables .......................................................................................................x
List of figures .................................................................................................. xii
Summary ............................................................................................................1

Chapter 1. Introduction ....................................................................................2
1.1 Introduction ....................................................................................................................... 3
1.2 Definition and prevalence of dementia ............................................................................. 5
1.3 Dementia and cognition .................................................................................................... 7
1.4 Tests of executive function ............................................................................................... 9
1.5 Activities of daily living in older people ........................................................................ 12
1.6 The relationship between cognition and activities of daily living in healthy
older people .................................................................................................................... 14
1.7 Activities of daily living in people with dementia .......................................................... 16
1.8 The relationship between cognition and activities of daily living in people
with dementia ................................................................................................................. 20
1.9 Aims of the thesis and research questions ...................................................................... 21
1.10 Research methodology .................................................................................................. 21
1.10.1 Ethical approvals ................................................................................................. 22
1.10.2 Participant recruitment ........................................................................................ 23
1.11 Structure of the thesis .................................................................................................... 24
1.12 Dissemination of findings ............................................................................................. 27
1.13 Conclusions ................................................................................................................... 28

Chapter 2. Executive function and activities of daily living in Alzheimer’s
disease: a correlational meta-analysis ...................................................... 30
2.1 Abstract ........................................................................................................................... 31
2.2 Introduction ..................................................................................................................... 32
2.3 Method ............................................................................................................................ 33
vi
2.3.1 Literature search strategy ...................................................................................... 33
2.3.2 Inclusion criteria ................................................................................................... 34
2.3.3 Procedure .............................................................................................................. 34
2.3.4 Statistical analysis ................................................................................................. 36
2.4 Results ............................................................................................................................. 38
2.4.1 Analysis of associations between ADL ratings and scores on individual
cognitive tests ....................................................................................................... 47
2.4.2 Moderator variables and heterogeneity ................................................................. 47
2.4.3 Associations between executive function scores and ratings based on
different methods of assessing ADL ability ......................................................... 51
2.4.4 Moderator variables and heterogeneity ................................................................. 51
2.4.5 Driving ability ....................................................................................................... 54
2.5 Discussion ....................................................................................................................... 54
2.6 Conclusions ..................................................................................................................... 57

Chapter 3. Predictors of objectively-assessed, self-rated and informant-
rated ability in instrumental activities of daily living in community-
dwelling older people: associations with executive function and cognitive
screening measures .................................................................................... 58
3.1 Abstract ........................................................................................................................... 59
3.2 Introduction ..................................................................................................................... 60
3.3 Method ............................................................................................................................ 63
3.3.1 Design ................................................................................................................... 63
3.3.2 Measures ............................................................................................................... 63
3.3.2.1 Functional ability ........................................................................................ 63
3.3.2.2 Executive function ...................................................................................... 65
3.3.2.2.1 Traditional neuropsychological tests ................................................ 65
3.3.2.2.2 Ecologically-valid neuropsychological tests .................................... 65
3.3.2.3 Screening tests for cognition and mood ...................................................... 66
3.3.3 Planned analyses ................................................................................................... 67
3.4 Results ............................................................................................................................. 68
3.4.1 The relationship between self-ratings, informant ratings and objective
functional ability ................................................................................................... 70
3.4.2 Accuracy of functional ratings compared with objective performance ................ 70
vii
3.4.3 The relationship between functional ability and executive and cognitive
screening tests ....................................................................................................... 72
3.4.4 Predictors of objective functional ability .............................................................. 72
3.5 Discussion ....................................................................................................................... 73
3.6 Conclusions ..................................................................................................................... 78

Chapter 4. Verbal fluency and awareness of functional deficits in early-
stage dementia ............................................................................................ 79
4.1 Abstract ........................................................................................................................... 80
4.2 Introduction ..................................................................................................................... 81
4.3 Method ............................................................................................................................ 84
4.3.1 Design ................................................................................................................... 84
4.3.2 Measures ............................................................................................................... 84
4.3.3 Procedure .............................................................................................................. 86
4.3.4 Planned analysis .................................................................................................... 86
4.4 Results ............................................................................................................................. 87
4.4.1 Participants ............................................................................................................ 87
4.4.2 Demographic analysis ........................................................................................... 88
4.4.3 Predictors of self-, informant and discrepancy ratings of everyday functioning .. 90
4.4.4 Verbal fluency and perceived functional ability ................................................... 91
4.4.5 Item analysis of functional impairment responses and associations with verbal
fluency .................................................................................................................. 94
4.5 Discussion ....................................................................................................................... 94
4.6 Conclusions ..................................................................................................................... 98

Chapter 5. Predictors of perceived functional ability in early-stage
dementia: self-ratings, informant ratings and discrepancy scores ....... 99
5.1 Abstract ......................................................................................................................... 100
5.2 Introduction ................................................................................................................... 101
5.3 Method .......................................................................................................................... 103
5.3.1 Design ................................................................................................................. 103
5.3.2 Measures ............................................................................................................. 103
5.3.3 Procedure ............................................................................................................ 104
5.3.4 Planned analysis .................................................................................................. 104
viii
5.4 Results ........................................................................................................................... 105
5.4.1 Predictors of self-rated functioning .................................................................... 107
5.4.2 Predictors of informant-rated functioning .......................................................... 107
5.4.3 Predictors of functional ability discrepancy scores ............................................ 114
5.5 Discussion ..................................................................................................................... 114
5.6 Conclusions ................................................................................................................... 118

Chapter 6. Awareness of functional ability in people with dementia:
cognitive correlates .................................................................................. 119
6.1 Abstract ......................................................................................................................... 120
6.2 Introduction ................................................................................................................... 121
6.3 Method .......................................................................................................................... 124
6.3.1 Design ................................................................................................................. 124
6.3.2 Measures ............................................................................................................. 124
6.3.2.1 Functional ability ...................................................................................... 124
6.3.2.2 Traditional neuropsychological tests ........................................................ 126
6.3.2.3 Ecologically-valid neuropsychological tests ............................................ 127
6.3.2.4 Screening tests for cognition and mood .................................................... 128
6.3.3 Procedure ............................................................................................................ 129
6.3.4 Planned analyses ................................................................................................. 130
6.4 Results ........................................................................................................................... 130
6.4.1 The relationship between self-ratings, informant ratings and objectively-
assessed functional ability .................................................................................. 133
6.4.2 Accuracy of ratings of functioning compared with objectively-assessed
performance ........................................................................................................ 133
6.4.3 Within-participant rating variability after controlling for objective
performance ........................................................................................................ 134
6.4.4 The relationship between functional ability and cognitive tests ......................... 137
6.4.5 Predictors of objectively-assessed functional ability .......................................... 138
6.5 Discussion ..................................................................................................................... 138
6.6 Conclusions ................................................................................................................... 142

Chapter 7. Discussion .................................................................................. 144
7.1 Introduction ................................................................................................................... 145
ix
7.2 Review of the key findings ........................................................................................... 147
7.3 Methodological considerations ..................................................................................... 156
7.4 Directions for future research ....................................................................................... 159
7.5 Practical implications of the study findings .................................................................. 163
7.6 Conclusions ................................................................................................................... 164

References ..................................................................................................... 166

Appendices .................................................................................................... 196

Appendix A. Ethical approval documents healthy older people study ............................... 197
Appendix B. Ethical approval documents dementia study ................................................. 198
Appendix C. Participant information sheet healthy older people study ............................. 206
Appendix D. Relative/friend information sheet healthy older people study ...................... 209
Appendix E. Participant & Relative/friend consent form healthy older people study ........ 212
Appendix F. Participant information sheet dementia study ................................................ 213
Appendix G. Relative/friend information sheet dementia study ........................................ 216
Appendix H. Participant consent form dementia study ...................................................... 219
Appendix I. Relative/friend consent form dementia study ................................................. 220
Appendix J. Direct Assessment of Functional Status ......................................................... 221
Appendix K. Informant rating questionnaire for the Direct Assessment of Functional
Status ............................................................................................................. 248
Appendix L. Geriatric Depression Scale - Short form (GDS-15) ....................................... 249
Appendix M. Apathy Scale ................................................................................................. 250
Appendix N. Spearman’s rho correlations between tests of executive function and
cognitive screening measures ........................................................................ 251
Appendix O. Functional Activities Questionnaire self-rating version ................................ 252
Appendix P. Functional Activities Questionnaire informant rating version ....................... 253
Appendix Q. Mean scores for individual self-ratings and informant ratings of functional
items and paired-sample t tests between individual functional items ........... 255
Appendix R. Relative Stress Scale ...................................................................................... 256
Appendix S. Zarit Burden Interview ................................................................................... 257
Appendix T. Spearman’s rho correlations between everyday memory, tests of executive
functioning and cognitive screening measures ............................................... 258
x