Understanding, recognising and preventing dehydration in older residents living in care homes

448 Pages·2016·7.88 MB·English

Understanding, recognising and preventing dehydration in
older residents living in care homes: a mixed methods study

Diane Kay Bunn
UEA Registration No. 9749659

A thesis submitted to the University of East Anglia in accordance with the
requirements of the Degree of Doctor of Philosophy

Norwich Medical School, University of East Anglia, UK

August 2016

This copy of the thesis has been supplied on condition that anyone who consults it is
understood to recognise that its copyright rests with the author and that use of any
information derived there from must be in accordance with current UK Copyright Law. In
addition, any quotation or extract must include full attribution.
Abstract
Aim
To recognise and understand how to prevent water-loss dehydration occurring in older
people living in care homes.
Background
Water-loss dehydration is common and linked to poor drinking, but prevention is likely to
be multi-faceted.
Methods
Three independent studies investigating hydration care in older care home residents
were conducted and the findings integrated (mixed methods, convergent parallel
design):
 Diagnostic accuracy of clinical signs and symptoms of dehydration.
 Systematic review investigating effectiveness of interventions and associations
of modifiable environmental factors on improving fluid intake and/or hydration
status.
 Qualitative study involving residents, families and care-staff in focus groups,
exploring challenges and facilitators in hydration care.
Results
In the diagnostic accuracy study, 188 residents (mean age 85 years, 66% women) were
recruited from 56 care homes. Clinical signs and symptoms were ineffective in identifying
older people with dehydration. The 23 included studies in the systematic review
addressed a range of strategies at carer, institutional and societal (‘macro’) levels to
improve fluid intake and hydration status, but high risk of bias in many studies meant
findings were inconclusive. Three themes emerged from the qualitative study: ‘meanings
and experiences of drinking’, ‘caring roles’, and ‘tensions and barriers to successful
drinking’. Integrated findings identified residents’ and families’ contributions to residents’
hydration care and preventing dehydration requires a multi-faceted approach. The
researcher-led quantitative studies of the systematic review indicated how macro factors
may impact on hydration care (along with institutional and carer-led factors). Findings
from the diagnostic accuracy should inform national guidelines at the macro level. The
qualitative study provided experiential perspectives and insights into relational care
between each care level and how these have positive and negative impacts on residents’
drinking.
Conclusion
Fluid intake is a physiological necessity to prevent dehydration. Supporting care home
residents to drink involves multi-levels of care and is a social experience.
(300 words)
Medline medical subject headings (MeSH): aged; beverages; dehydration; diagnostic
tests, routine; drinking; geriatrics; long-term care; osmolar concentration; qualitative
research; residential facilities; review, systematic.

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Acknowledgements

PhD theses rarely develop in isolation. The author is the ‘frontman’ who has coordinated
the team effort which has gone into its completion. As the author, I would like to thank
‘the team’ who has been behind me. This begins, most importantly, with the participants,
all of whom either lived, worked or visited in care homes across Norfolk and Suffolk.
Thank you for your willingness to take part, your time and your suggestions. I am also
very grateful to the members of the DRIE Steering Group and Advisory Groups for your
advice and encouragement along the way.
A special ‘thank you’ goes to my supervisors, Lee and Fiona, for your confidence in me
and for your constant back-up, support, availability and insights. Lee, your dedication
and commitment to getting a job done has been inspiring; and Fiona, your patience and
strong guidance throughout this process has been invaluable.
I have an enormous debt of gratitude to my supportive family, but particularly Jonathan,
my husband, without whom this would have not happened. His encouragement, listening
ears and practical help have enabled me to follow my dream of attempting a PhD. If ever
there was an award for partners of PhD students, he needs to be first in line!
I am also indebted to friends and colleagues for their practical and moral support
throughout this study. In particular, Florence for being part of my review team; Anne and
Michael, two of my co-facilitators; Steph for being a co-reviewer, co-facilitator, duplicate
coder and part of my focus group training team (together with Kathleen and Margaret) –
thank you! Also thank you to Leen and Peter for your assistance with translating the
German paper included in the review.
Finally, my thanks go to the NIHR for providing the funding which set the scene for all
this to happen.

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Funding Statement

The fees and training costs for my PhD were funded by the National Institute of Health
Research (NIHR). My primary supervisor, Lee Hooper, was awarded a NIHR Fellowship
Programme grant (NIHR-CDF-2011-04-025) to develop a portfolio of clinical and
physical signs to identify impending or current water-loss dehydration in older people
residing in care homes and to investigate the one and two year outcomes associated
with water-loss dehydration. Embedded within this award was funding for a PhD to
enable me to work with Lee, contribute to the ongoing development of this study and to
undertake independent research within it, as well as to develop further related and
independent research. My contributions are detailed in each chapter.

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List of Contents

ABSTRACT.................................................................................................................................... 2
ACKNOWLEDGEMENTS .............................................................................................................. 3
FUNDING STATEMENT ................................................................................................................ 4
LIST OF CONTENTS ..................................................................................................................... 5
LIST OF TABLES ........................................................................................................................ 10
LIST OF FIGURES ...................................................................................................................... 11
GLOSSARY ................................................................................................................................. 13
CHAPTER 1: INTRODUCTION ............................................................................................. 14
1.1 CONTRIBUTIONS ............................................................................................................ 14
1.2 AIM AND INTRODUCTION TO CHAPTER 1 .......................................................................... 14
1.3 INVESTIGATING WATER-LOSS DEHYDRATION IN OLDER CARE HOME RESIDENTS.................. 14
1.4 DRINKING AND HYDRATION CARE IN CARE HOMES ............................................................ 16
1.5 HYDRATION CARE IN CARE HOMES, IS IT A PROBLEM? ...................................................... 17
1.6 RESEARCH TO ADDRESS THE GUIDELINES ....................................................................... 19
1.6.1 Section 14(1) of the CQCs guidelines ................................................................. 19
1.6.2 Section 14(4)(a) of the CQCs guidelines ............................................................ 20
1.6.3 Section 14(4)(d) of the CQCs guidelines ............................................................ 20
1.7 THE RESEARCH PROBLEM .............................................................................................. 21
1.8 MIXED METHODS APPROACH .......................................................................................... 21
1.9 THESIS OVERVIEW ......................................................................................................... 22
1.10 SUMMARY AND CONCLUSIONS FROM CHAPTER 1 ............................................................. 23
CHAPTER 2: LITERATURE REVIEW .................................................................................. 24
2.1 CONTRIBUTIONS ............................................................................................................ 24
2.2 AIM AND INTRODUCTION TO CHAPTER 2 .......................................................................... 24
2.3 ROLE OF WATER IN THE BODY ......................................................................................... 24
2.4 HOMEOSTATIC CONTROL OF BODY WATER ....................................................................... 24
2.5 WHAT IS DEHYDRATION? ................................................................................................ 25
2.6 EFFECTS OF AGEING ON BODY HYDRATION ...................................................................... 28
2.6.1 Physiologic risk factors for dehydration .............................................................. 28
2.6.2 Physical and behavioural factors risk factors for dehydration ............................. 30
2.7 COMORBIDITIES ASSOCIATED WITH DEHYDRATION ........................................................... 34
2.7.1 Cognition ............................................................................................................. 34
2.7.2 Constipation ........................................................................................................ 34
2.7.3 Coronary disease ................................................................................................ 35
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2.7.4 Disability .............................................................................................................. 35
2.7.5 Decubitus ulcers .................................................................................................. 35
2.7.6 Stroke .................................................................................................................. 35
2.7.7 Urinary tract infections ........................................................................................ 36
2.7.8 Urolithiasis ........................................................................................................... 36
2.7.9 Venous thromboembolism .................................................................................. 36
2.7.10 Other morbidities ................................................................................................. 36
2.8 DEHYDRATION AND HOSPITAL ADMISSIONS AND MORTALITY ............................................. 37
2.9 RECOGNISING DEHYDRATION IN OLDER PEOPLE............................................................... 38
2.9.1 Screening and diagnostic tests generally ........................................................... 38
2.9.2 Screening and diagnostic tests in dehydration ................................................... 38
2.10 FLUID INTAKE IN OLDER PEOPLE LIVING IN CARE HOMES ................................................... 43
2.10.1 Patterns of drinking in care homes ...................................................................... 45
2.11 ISSUES WITH MEASURING FLUID INTAKE ........................................................................... 46
2.12 HYDRATION CARE IN CARE HOMES .................................................................................. 46
2.13 PUBLICATIONS ARISING FROM CHAPTER 2 ....................................................................... 51
2.14 SUMMARY AND CONCLUSIONS FROM CHAPTER 2 ............................................................. 51
CHAPTER 3: AIMS AND OBJECTIVES ............................................................................... 53
3.1 MY CONTRIBUTION ......................................................................................................... 53
3.2 AIM AND INTRODUCTION TO CHAPTER 3 .......................................................................... 53
3.3 THESIS RESEARCH QUESTION, AIM AND OBJECTIVES ........................................................ 53
3.4 RESEARCH QUESTIONS, AIMS, PURPOSE AND OBJECTIVES FOR THE COMPONENT STUDIES . 54
3.4.1 The Diagnostic Accuracy study ........................................................................... 54
3.4.2 The Systematic Review ....................................................................................... 55
3.4.3 The Qualitative Study .......................................................................................... 56
3.5 SUMMARY AND CONCLUSIONS FROM CHAPTER 3 ............................................................. 57
CHAPTER 4: DIAGNOSTIC ACCURACY STUDY ............................................................... 58
4.1 CONTRIBUTIONS ............................................................................................................ 58
4.2 AIM AND INTRODUCTION TO CHAPTER 4 .......................................................................... 58
4.3 BACKGROUND ............................................................................................................... 58
4.3.1 Screening for water-loss dehydration in older people ......................................... 58
4.3.2 Serum osmolality as the reference standard ...................................................... 59
4.4 STUDY OUTLINE ............................................................................................................. 60
4.5 ETHICAL CONSIDERATIONS ............................................................................................. 61
4.6 METHODS ..................................................................................................................... 62
4.6.1 Recruitment of care homes ................................................................................. 62
4.6.2 Recruitment of residents ..................................................................................... 62
4.6.3 Interviews with residents ..................................................................................... 64
4.6.4 Clinical signs and symptoms, ‘index tests’ .......................................................... 65
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4.6.5 Serum osmolality, ‘reference standard’ ............................................................... 72
4.6.6 Interviews with staff about participating residents ............................................... 72
4.6.7 Interviews with staff about the care home itself .................................................. 73
4.6.8 Data management ............................................................................................... 73
4.6.9 Data analysis ....................................................................................................... 73
4.6.10 Adverse events .................................................................................................... 75
4.7 RESULTS ....................................................................................................................... 75
4.7.1 Recruitment of care homes and residents .......................................................... 75
4.7.2 Baseline characteristics of the DRIE population ................................................. 76
4.7.3 Representativeness of the DRIE study population ............................................. 79
4.7.4 Diagnostic accuracy of the index tests ................................................................ 80
4.7.5 Diagnostic accuracy of index tests analysed as categorical variables ............... 80
4.7.6 Diagnostic accuracy of index tests analysed as continuous variables ............... 84
4.8 DISCUSSION ................................................................................................................ 106
4.8.1 Statement of principal findings .......................................................................... 106
4.8.2 Comparison with other studies .......................................................................... 106
4.8.3 Limitations of the study ..................................................................................... 108
4.8.4 Strengths of the study ....................................................................................... 112
4.9 PUBLICATIONS ARISING FROM CHAPTER 4 ..................................................................... 114
4.10 SUMMARY AND CONCLUSIONS FROM CHAPTER 4 ........................................................... 115
CHAPTER 5: SYSTEMATIC REVIEW ................................................................................ 117
5.1 CONTRIBUTIONS .......................................................................................................... 117
5.2 AIM AND INTRODUCTION TO CHAPTER 5 ........................................................................ 117
5.3 METHODS ................................................................................................................... 117
5.3.1 Ethical considerations ....................................................................................... 117
5.3.2 Refining the research question and development of the protocol ..................... 118
5.3.3 Participants and setting ..................................................................................... 118
5.3.4 Interventions and exposures ............................................................................. 119
5.3.5 Comparators ...................................................................................................... 119
5.3.6 Outcomes .......................................................................................................... 120
5.3.7 Study design ...................................................................................................... 120
5.3.8 Study selection .................................................................................................. 121
5.3.9 Data extraction .................................................................................................. 122
5.3.10 Risk of bias and methodological quality ............................................................ 122
5.3.11 Data synthesis ................................................................................................... 124
5.3.12 Protocol changes............................................................................................... 125
5.4 RESULTS ..................................................................................................................... 125
5.4.1 Selection of studies ........................................................................................... 125
5.4.2 Risk of bias, validity and methodological quality ............................................... 136
5.4.3 Findings from the studies .................................................................................. 139
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5.5 DISCUSSION ................................................................................................................ 159
5.5.1 Meta-analysis .................................................................................................... 161
5.5.2 Secondary outcomes ........................................................................................ 161
5.6 PUBLICATIONS ARISING FROM CHAPTER 5 ..................................................................... 162
5.7 SUMMARY AND CONCLUSIONS FROM CHAPTER 5 ........................................................... 162
CHAPTER 6: QUALITATIVE STUDY ................................................................................. 165
6.1 CONTRIBUTIONS .......................................................................................................... 165
6.2 AIM AND INTRODUCTION TO CHAPTER 6 ........................................................................ 165
6.3 METHODOLOGICAL CONSIDERATIONS ............................................................................ 166
6.3.1 Reflexivity .......................................................................................................... 167
6.3.2 Research strategy ............................................................................................. 167
6.3.3 Ethical considerations ....................................................................................... 171
6.3.4 Trustworthiness and Rigour .............................................................................. 175
6.4 METHODS ................................................................................................................... 176
6.4.1 Recruitment ....................................................................................................... 176
6.4.2 Focus Groups .................................................................................................... 177
6.4.3 Thematic analysis.............................................................................................. 180
6.5 FINDINGS .................................................................................................................... 182
6.5.1 Characteristics of care homes, participants and focus groups ......................... 182
6.5.2 Findings: theme descriptions ............................................................................ 190
6.5.3 Theme 1, ‘Meaning and experiences of drinking’ ............................................. 199
6.5.4 Theme 2, ‘Caring roles’ ..................................................................................... 250
6.6 DISCUSSION ................................................................................................................ 291
6.6.1 Summary of findings ......................................................................................... 291
6.6.2 Relating this qualitative study to other similar studies ...................................... 296
6.6.3 Limitations to this study ..................................................................................... 298
6.6.4 Strengths of this study ....................................................................................... 301
6.7 PUBLICATIONS ARISING FROM CHAPTER 6 ..................................................................... 302
6.8 SUMMARY AND CONCLUSIONS FROM CHAPTER 6 ........................................................... 302
CHAPTER 7: DISCUSSION AND CONCLUSIONS ........................................................... 304
7.1 CONTRIBUTIONS .......................................................................................................... 304
7.2 AIM AND INTRODUCTION TO CHAPTER 7 ........................................................................ 304
7.3 CONCLUSIONS FROM THE THREE INDIVIDUAL STUDIES .................................................... 304
7.3.1 Diagnostic Accuracy study (Chapter 4) ............................................................. 304
7.3.2 The Systematic Review (Chapter 5) ................................................................. 304
7.3.3 Qualitative Study (Chapter 6) ............................................................................ 305
7.4 INTEGRATING THE FINDINGS FROM THE THREE COMPONENT STUDIES .............................. 305
7.4.1 Methods for integrating findings ........................................................................ 307
7.4.2 Integrated findings ............................................................................................. 311
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7.4.2.14 Role of care homes to support ...................................................................... 319
7.4.3 Discussion ......................................................................................................... 322
7.4.4 Recommendations for care and future research ............................................... 328
7.5 PUBLICATIONS ARISING FROM CHAPTER 7 ..................................................................... 332
7.6 CONCLUSIONS OF THIS THESIS ..................................................................................... 332
LIST OF ABBREVIATIONS....................................................................................................... 334
REFERENCE LIST .................................................................................................................... 337
APPENDICES ............................................................................................................................ 357

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List of Tables

Table 2-1: Definitions of dehydration ........................................................................................... 27
*
Table 2-2: Risk factors associated with dehydration amongst older people ............................... 31
Table 2-3: Risk factors associated with low fluid intake amongst older people ........................... 33
Table 2-4: Commonly-used signs and symptoms of dehydration ................................................ 42
Table 2-5: Mean fluid intakes of older people living in long-term care ........................................ 45
Table 4-1: Clinical signs and symptoms, ‘index tests’, used in the DRIE Study .......................... 66
Table 4-2: Baseline characteristics of DRIE population ............................................................... 78
Table 4-3: Type of care provided by care homes in DRIE compared to those in Norfolk and
Suffolk combined and England as a whole.................................................................. 79
Table 4-4: Sensitivity and specificity (95%CI) for each index test assessed dichotomously ....... 81
Table 4-5: Index tests assessed as continuous variables: skin assessments, capillary refill and
foot vein filling .............................................................................................................. 85
Table 4-6: Index tests assessed as continuous variables: vital signs ......................................... 86
Table 4-7: Index tests assessed as continuous variables: urinalysis .......................................... 89
Table 4-8: Test 32.3 (skin turgor inside forearm) sensitivity and specificity for each cut-off, when
AUC transposed ........................................................................................................ 101
Table 4-9: Interrater reliability of index tests assessed as categorical variables, using kappa . 103
Table 4-10: Interrater reliability of index tests assessed as continuous variables, using intraclass
coefficient (ICC) ......................................................................................................... 105
Table 4-11: Comparing sensitivity and specificity of ‘expression of fatigue’* ............................ 107
Table 5-1: Brief characteristics of included intervention studies* .............................................. 127
Table 5-2: Brief characteristics of included observational studies*............................................ 134
Table 5-3: Risk of bias, observational studies* .......................................................................... 138
Table 5-4: Findings from included intervention studies* ............................................................ 140
Table 5-5: Before-after and crossover intervention studies reporting secondary outcomes* .... 147
Table 5-6: Controlled intervention studies reporting secondary outcomes* .............................. 149
Table 5-7: Institutional factors and their association with dehydration or low fluid intake* ........ 153
Table 6-1: Profile of participating homes ................................................................................... 183
Table 6-2: Profile of participants, by focus group type ............................................................... 187
Table 6-3: Themes, sub-themes and categories ....................................................................... 192
Table 7-1: Integrating the findings from the diagnostic accuracy study (‘DA’), the systematic
review and the qualitative study ................................................................................ 308

All abbreviations used in the tables are defined in the ‘List of Abbreviations’, page 334

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