Article Text

Protocol
Assessing caregiver burden in advanced kidney disease: protocol for a systematic review of the measurement properties of instruments and tools
  1. Ravi Shankar1,
  2. Nan Luo2,
  3. Yee Wei Lim1,3,
  4. Priyanka Khatri3,4,5,6,
  5. Leanne Leong3,4,5,6,
  6. Geraldine Yu-Xuan Teo5,6,
  7. Amartya Mukhopadhyay3,5,6,7,
  8. Jason Choo8,
  9. Horng Ruey Chua3,4,
  10. Gim-Gee Teng3,5,6,9,
  11. Jason Phua3,5,6,7,
  12. Wei Zhen Hong3,4,5,6
  1. 1Medical Affairs - Research, Innovation and Enterprise, Alexandra Hospital, National University Health System, Singapore
  2. 2Saw Swee Hock School of Public Health, National University Singapore, Singapore
  3. 3Yong Loo Lin School of Medicine, National University of Singapore, Singapore
  4. 4Division of Nephrology, Department of Medicine, National University Hospital, National University Health System, Singapore
  5. 5Chronic Programme, Alexandra Hospital, National University Health System, Singapore
  6. 6Fast Programme, Alexandra Hospital, National University Health System, Singapore
  7. 7Division of Respiratory and Critical Care Medicine, Department of Medicine, National University Hospital, National University Health System, Singapore
  8. 8Department of Renal Medicine, Singapore General Hospital, Singapore
  9. 9Division of Rheumatology, Department of Medicine, National University Hospital, National University Health System, Singapore
  1. Correspondence to Dr Wei Zhen Hong; wei_zhen_hong{at}nuhs.edu.sg

Abstract

Introduction Caregiver burden is a significant issue in the care of patients with advanced kidney disease. Its assessment is crucial for evaluating the needs of caregivers and for the development of interventions to support them. Several instruments have been developed to measure caregiver burden in these patients. However, the measurement properties of these instruments have not been systematically reviewed.

Methods and analysis This systematic review will include a comprehensive search of databases including PubMed, CINAHL, Embase, Cochrane Library, SCOPUS and Web of Science by using keywords and MeSH terms to identify relevant studies starting from each database inception to 1 January 2024 and covering papers in English. The search strategy will combine relevant keywords and database-specific subject headings related to the following concepts: (1) caregivers, (2) burden, stress, distress, (3) chronic kidney disease, end-stage kidney disease, dialysis. Reference lists of eligible articles will also be hand searched. We will include quantitative and qualitative studies evaluating measurement properties of instruments assessing caregiver burden in caregivers of adult patients (aged ≥18 years). Data will be extracted from the selected studies and analysed using the COnsensus-based Standards for the selection of health Measurement INstruments checklist as the study quality assessment tool. Subsequently, the van der Vleuten utility index will be used to critique and categorise the instruments. A narrative that synthesises the utility of all instruments will be presented along with recommendations for the selection of instruments depending on specific clinical contexts. This systematic review will provide an overview of the measurement properties of available instruments, including discussion on reliability, validity and responsiveness. Results from the review may give rise to the subsequent development of most appropriate instrument that could be applied to the assessment of caregiver burden in advanced kidney disease.

Ethics and dissemination Ethics approval is not required as this study will merely synthesise data from published studies. The results will be disseminated through peer-reviewed publications as well as conference presentations.

PROSPERO registration number CRD42023433906.

  • Chronic renal failure
  • Dialysis
  • End stage renal failure
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STRENGTHS AND LIMITATIONS OF THIS STUDY

  • The review implements a comprehensive search strategy across databases, reference lists and author contacts to comprehensively capture all studies validating caregiver burden instruments in late-stage chronic kidney disease patients.

  • The review will adopt Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for reporting to ensure transparency, completeness, and applicability; and COnsensus-based Standards for the selection of health Measurement INstruments guidelines for in-depth analysis of the methodological quality of included studies on measurement properties.

  • A dual reviewer process for screening, extraction and adjudicating disagreements is used to systematically minimise risk of bias and errors at all review stages.

  • The restriction to English-language studies risks precluding some potentially relevant non-English caregiver burden research from being considered.

  • Variability in study designs and conceptualisations of caregiver burden may impact interpretability and synthesis of results.

Introduction

Chronic kidney disease (CKD) is one of the most common chronic diseases in the world with a global prevalence of 11.0%–13.4%.1 Patients with advanced kidney disease comprise of individuals with CKD who are in stage 4 or 5.2 Caregivers of patients with CKD are often required to take on multiple responsibilities and tasks while caring for patients, including the administration of medications, accompanying patients for medical appointments as well as for providing psychosocial and emotional support.3 The burden that arises from these caregiving responsibilities could lead to a reduced quality of life and a compromised state of mental health.4 Caregiver burden can be defined as the strain or load borne by a person who cares for a chronically ill, disabled or elderly family member.3–7 Caregiver burden typically manifests as high rates of psychological distress, mental health diagnoses, fatigue, sleep disturbances and suicide attempts, which, if left unattended, may lead to a rippling effect on patients’ health and, eventually, the healthcare system.5 8–14 Caregiver burden in the context of this research is defined as the multifaceted strain experienced by caregivers encompassing psychological, physical, financial, emotional and social stressors. This comprehensive definition guides our inclusion and exclusion criteria for selecting studies in this systematic review.

The urgency of addressing the issue of caregiver burden has been highlighted by studies conducted in both high-income countries like the USA and lower to middle-income countries like Turkey, Vietnam, Jordon, India, China Nigeria.8 15–22 Factors that contribute to caregiver burden may be categorised into patient-related and caregiver-related factors. Patient-related factors include the extent to which patients are dependent on their caregivers for physical and emotional well-being, which in turn depends on the patient’s functional limitations, cognitive impairment and disease severity.23 Caregiver-related factors include the demographics of caregivers, the nature of their caregiving role, relationship with the patients, health status of caregivers and financial strain that results from caregiving.24

Measuring caregiver burden in patients with advanced kidney disease is important for understanding the impact of caregiving, identifying areas where caregivers are experiencing difficulty, supporting targeted interventions for mitigating the impact of caregiver burden, tracking changes in caregiver burden over time as disease severity changes, understanding the differences in burden for various types of caregivers (formal, informal and caregivers with cultural differences) and in evaluating targeted healthcare policies and programmes for caregivers.25 26

However, the measurement properties of available assessment tools have not been systematically evaluated for advanced kidney disease. The absence of appraisal of measurement properties restricts the evidence-based selection of caregiver burden assessment tools optimised for specific research contexts, cultural groups, informal or formal caregiver populations and healthcare settings in advanced kidney disease. Therefore, a systematic review of the measurement properties of tools to assess caregiver burden in advanced kidney disease could guide clinicians on the appropriate use of different tools depending on specific clinical contexts.

This study specifically addresses advanced kidney disease because this disease is distinct in its severity and complexity, imposing a uniquely multifaceted and intense burden on caregivers when compared with other chronic conditions.27 With its relentless progression, high mortality and extensive treatment demands including long-term dialysis, providing care to patients with advanced kidney disease demands a different set of skills, a certain degree of resilience and resourcefulness. Current generic tools for assessing caregiver burden in chronic diseases may fall short in accurately capturing the full range of emotional, physical and psychological stresses unique to this context. Our systematic review aims to identify and evaluate these existing tools, highlighting the need for precise, disease-specific instruments. This is crucial for understanding the unique caregiver burden in advanced kidney disease and developing effective support strategies and interventions.

Instruments used for measuring caregiver burden in earlier studies

There are several instruments for measuring caregiver burden in advanced kidney disease, including the Zarit Burden Interview (ZBI), Short Form 36, Centre for Epidemiological Studies Depression Scale, Beck Depression Inventory, Depression Anxiety and Stress Scale, Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index, Caregiver Burden Scale, Brief Symptom Inventory, Psychological Adjustment to Illness Scale, Jalowiec Coping Scale, Caregiver Burden Inventory, Caregiver Strain Index and so on.3–6 8 These instruments account for the differences in various aspects of caregiving, population and cultural appropriateness of instruments, and an evolving understanding of the caregiving experience. A systematic review covering 61 studies, identified 70 different scales for assessment of caregiver burden and found significant heterogeneity in study design and outcome measures, which made comparisons between studies difficult.4

These instruments have been mainly validated in specific samples or cultures. However, it is important to ensure that these instruments are appropriate for the population in question and to consider the cultural nuances when interpreting the results. It would be clinically relevant to examine the measurement properties of these instruments in more diverse populations and to conduct longitudinal studies, to better understand the temporal dynamics of caregiver burden in the context of patients with advanced kidney disease. Furthermore, it would be useful to evaluate the responsiveness of these instruments, which refers to the ability of an instrument to detect changes in the outcome of interest over time.3 5

The objectives of our review are:

  • To identify all available instruments that have been developed to measure caregiver burden in patients with advanced kidney disease. To provide a systematic overview of the existing research on all available instruments.

  • To review the descriptive aspects of each instrument (eg, respondent requirements, administration type, response format and so on).

  • To evaluate the measurement properties of these instruments, including internal consistency, reliability, measurement error, content validity (including face validity), structural validity, hypothesis-testing, cross-cultural validity, responsiveness, interpretability, reproducibility agreement, floor and ceiling effects.

  • To identify the most appropriate instruments for measuring caregiver burden in patients with advanced kidney disease.

Methods and analysis

A well-defined research question is developed using the SPIDER (Sample, Phenomenon of Interest, Design, Evaluation, Research type) framework.28 The research question is focused on assessing the descriptive aspects and components pertaining to the measurement properties of tools deployed to evaluate caregiver burden in advanced kidney disease, which include internal consistency, reliability, measurement error, content validity (including face validity), structural validity, hypothesis-testing, cross-cultural validity, responsiveness, interpretability, reproducibility agreement and floor and ceiling effects.

A search for all relevant studies will be conducted on a set of relevant databases using appropriate search terms (online supplemental file appendix 1). A two-step systematic search will be conducted between September 2023 and June 2024. The first round of search is targeted to provide an inventory of all eligible caregiver burden assessment tools. The second round of search aims to locate the evaluation studies corresponding to all the instruments filtered in the first search (figure 1, figure 2). The search will be conducted in multiple databases to ensure a comprehensive search for all relevant studies. The search will be limited to studies that have been published in peer-reviewed journals and that have been written in English.

Figure 1

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart for the first search.

Figure 2

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart for the second search.

Search strategy

Eligible articles will be screened through PubMed, CINAHL, Embase, MEDLINE, PsycINFO, Cochrane Library, SCOPUS and Web of Science databases, with search strategies devised in accordance to each database. The search will cover studies published in English from each database inception to 1 January 2024. A search strategy for all the databases is provided in online supplemental appendix I. The SPIDER framework will be adopted to perform a comprehensive search for relevant studies.28 The SPIDER framework is a systematic strategy for searching for qualitative and mixed-methods research studies, defining key elements of non-quantitative research questions.29

Sample

The sample to be examined is representative of the caregivers of patients with advanced kidney disease. This includes consideration of demographic factors such as age, gender, race and socioeconomic status. The sample size will be reviewed to ensure that the study is adequately powered for the analysis.

Phenomenon of interest

Assessment of caregiver burden is the phenomenon of interest to be studied. The instrument that measures caregiver burden should be appropriate for the population in question and one that measures the physical, psychological, emotional, social and financial aspects of caregiver burden. The instruments will include the ones that measure specific aspects of caregiver burden as well as those assessing multiple dimensions.

Design

Types of study design (eg, quantitative method or mixed methods, experimental, quasi-experimental, pre-experimental and non-experimental studies including cross-sectional, cohort, non-randomised or randomised controlled trials (RCTs), case studies, narrative and scoping reviews), the methodology of data collection (eg, self-report, observation) and the statistical methods used to analyse the data. All studies will be assessed for appropriateness of study design, with reference to the phenomenon of interest.

Evaluation

Evaluation of the measurement properties of the instrument will include considerations such as reliability (eg, test–retest, internal consistency), validity (eg, construct, cross-cultural differences) and responsiveness. All instruments will be assessed for adequacy of its individual measurement properties, with reference to the study population.

Research type

Studies encompassing both the quantitative, qualitative and mixed-methods approaches will be considered.

All studies determined to be eligible in accordance with the inclusion selection questions (online supplemental appendix II) will be selected and included in the review. If required, studies’ original development papers may be referenced from, with the authors of these papers further consulted for extraction of missing but pertinent information. The studies will be evaluated independently by two reviewers involved. The two reviewers will independently screen the articles in accordance to the inclusion criteria, extract relevant data and assess the studies for risk of bias. Any discrepancies will be resolved through consensus or with a third reviewer.

Inclusion and exclusion criteria

Inclusion criteria

  1. Type of participants: caregivers of patients with advanced kidney disease (ie, stage 4 and 5 CKD, patients with end-stage kidney disease on dialysis or those managed conservatively). Both formal and informal caregivers will be included.

  2. Condition/domain of interest: studies measuring caregiver burden (physical, psychological, emotional, financial and so on) and related concepts.

  3. Types of instruments: any tool, scale or questionnaire used to assess caregiver burden. Both multidimensional and unidimensional instruments will be included. No inclusion or exclusion based on theoretical grounding of instruments.

  4. Measurement properties: studies evaluating one or more measurement properties—reliability, validity (content validity, structural validity, hypothesis testing, cross-cultural validity, etc), responsiveness, interpretability, reproducibility and floor/ceiling effects.

  5. Study design and comparisons: all study designs include RCTs, cohort studies, case–control studies, cross-sectional studies, quasi-experimental studies.

  6. Outcome measures: measures of caregiver burden and related concepts.

  7. Publication type and status: peer-reviewed published studies. Fully published papers in which measurement property analysis details are reported.

  8. Language: published in the English language.

  9. Time frame of the studies: from database inception to 1 January 2024.

Exclusion criteria

  1. Type of participants: studies involving caregivers of early-stage chronic kidney disease or acute kidney injury or kidney transplant patients.

  2. Type of instruments: instruments not measuring caregiver burden or related concepts. Instruments only measuring patient-reported outcomes.

  3. Study design: case studies, case series, reviews, commentaries, viewpoints, editorial articles, protocols, single group cross-sectional analysis.

  4. Outcomes: studies not reporting measures of caregiver burden or related constructs. Studies only reporting patient-centred outcomes or kidney disease outcomes.

  5. Publication type and language: non-English studies, conference abstracts or proceedings, dissertations, book chapters, protocols and study plans for tool validation studies that do not report details of measurement properties.

Finally, data will be extracted from the included studies (online supplemental appendix III), and the quality of the studies will be assessed using COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist.30 The extracted data will include information such as the sample size, the instrument used to measure caregiver burden, the methodology used to evaluate the measurement properties, and the results of the study. By analysing the results of eligible studies, extracted data can be synthesised. From here, conclusions on the measurement properties of instruments used to assess caregiver burden in patients with advanced kidney disease can be made. A narrative synthesis will be conducted to summarise the findings of the included studies. The results will be reported in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Assessment of measurement properties

Several parameters are used to assess the measurement properties of instruments designed to measure caregiver burden among patients with advanced kidney disease (table 1). These parameters, although interrelated, are mutually exclusive.

Table 1

Quality criteria for measurement properties33

Since a gold standard for the assessment of caregiver burden in advanced kidney disease does not exist currently, the measurement property ‘criterion validity’ will not be considered for the purpose of this systematic review.

Risk of bias and assessment of study quality

In order to ensure that the studies included in the review are reliable, the COSMIN checklist will be used to evaluate the quality of the studies. COSMIN allows for a comprehensive assessment of the methodological quality of systematic reviews. This is achieved through evaluating the quality of each study based on domains such as the representativeness of eligible studies, measurement properties of reference instruments and the impact of missing data. In addition, the COSMIN checklist is used to assess the quality of studies that report on the measurement properties of an instrument, such as its reliability, validity and responsiveness.

The four main domains in evaluating the quality of studies are study design and conduct, measurement properties, sample characteristics and conclusions and reporting (figure 3). The COSMIN checklist is completed for each study by answering questions in each of these domains. Based on the answers provided for each domain, the quality of the studies is rated as either ‘good’, ‘fair’ or ‘poor’. Table 2 presents the COSMIN definitions of quality levels using the modified Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach, along with their corresponding definitions.

Table 2

COSMIN quality levels and definitions (modified GRADE approach)

Figure 3

The four-step procedure to complete the COSMIN checklist.30 COSMIN, COnsensus-based Standards for the selection of health Measurement INstruments; IRT, item response theory.

A detailed grading system for ‘good’, ‘fair’ and ‘poor’ quality classifications is provided below:

Good quality: strong and appropriate study design (eg, RCT, cohort study); adequate sample size; low overall risk of bias; directness of evidence for the target population; detailed reporting of measurement properties and results; appropriate statistical analysis methods; no issues identified that would lower confidence in the results.

Fair quality: moderate sample size; some concerns about applicability of study design or execution; some uncertainties or inconsistencies in results; lack of detail on certain measurement properties; outdated methods or suboptimal statistics; some concerns that may lower confidence in the results.

Poor quality: inadequate sample; high risk of bias due to study design or conduct limitations; indirectness of evidence for the target population; incomplete or selective reporting of measurement properties; inappropriate statistical methods; issues that severely lower confidence and reliability of results

These quality levels are used to assess the methodological quality and risk of bias in studies, which evaluate the measurement properties of instruments and tools. The quality level assigned to a study helps determine the strength of evidence provided by that study, subsequently influencing the overall assessment of the measurement properties.

The van der Vleuten utility index

The van der Vleuten utility index is a method for assessing the utility of a measurement instrument.31 The utility of a measurement instrument is dependent on its ability to accurately measure the specified intended outcome, and the practicality of its use in a specific setting. The utility index is calculated by multiplying the validity coefficient of an instrument by a practicality coefficient.

There are various empirical research and statistical analysis methods to estimate validity coefficients, including correlational analyses, factor analyses and expert judgement. The specific calculation depends on the nature of the instrument and the validation study design. The practicality coefficient takes into consideration factors such as time, cost, administration procedures, scoring and resources required to implement the instrument and is typically determined based on expert judgement, experience and considerations of the specific context in which the instrument will be used.

In the context of measuring caregiver burden in patients with advance kidney disease, the utility index can be used to evaluate the measurement properties of instruments used to measure caregiver burden. By calculating the utility index for different instruments, researchers can compare the overall utility of different instruments and select the instrument best suited for their specific study population.

Data synthesis

The data from the included studies will be synthesised by summarising the findings for each instrument and grouping the studies by their quality assessment. The results of the systematic review will be interpreted in the context of the quality of the studies, the consistency and heterogeneity of the results. No meta-analysis is planned due to the expected heterogeneity in the methodologies, instruments and populations studied across different research works. Rather, a narrative synthesis based on the data analysis will be provided.32

Descriptive statistics will be used to present the general characteristics of the studies included in the systematic review to contextualise the findings and identify any patterns or trends across the studies. The quality of methods and measurement property results will be tabulated. The quality of methods table will assess the rigour and validity of the studies, considering factors such as study design, sample representativeness and data collection procedures. This table will enable a comprehensive evaluation of the methodological quality of each study, ensuring the reliability of the findings. Furthermore, a table based on all of the quality criteria of the COSMIN will be used to present the psychometric properties of each systematic review and meta-analysis tool.

Patient and public involvement

None.

Ethics and dissemination

This systematic review will synthesise data from published studies; therefore, ethics approval is not required. The findings will be disseminated through various channels, including publication in a peer-reviewed journal and presentation at relevant webinars and conferences. The review findings will be published in open-access journal to ensure accessibility. The importance of assessing and addressing caregiver burden will be highlighted through knowledge dissemination among healthcare providers, researchers, caregivers and kidney disease patient organisations. It may encourage uptake of suitable instruments in clinical research and practice.

This review will provide valuable insights into the measurement properties of the various instruments used to assess caregiver burden in advanced kidney disease. This may inform selection of appropriate instruments in future studies and ensure accurate assessment of caregiver burden. The results will also reveal any gaps in existing instruments and areas requiring further research, which may also inform development of new instruments, interventions and supports for caregivers of advanced kidney disease patients.

Discussion

This systematic review aims to critically evaluate the methodological quality of existing research that centres on the measurement properties of tools that have been developed to assess caregiver burden in patients with advanced kidney disease. There is a need to standardise a validated clinical tool for assessment of caregiver burden in this area. Findings from this review could advance clinical research in the field of caregiver burden in patients with advanced kidney disease. Through identification of a validated clinical tool that could be applied uniformly across different clinical and research settings, the consistency and comparability of research findings in this area may be improved on.

The findings of this systematic review will be reported in accordance with the PRISMA guidelines. The PRISMA framework ensures transparent reporting of the review process, including study selection, data extraction and assessment of methodological quality. Adherence to these guidelines will enhance the transparency and reproducibility of results from this systematic review. Results from this review will guide the study team in planning future prospective and randomised studies in the field of caregiver burden in patient with advanced kidney disease.

There are some limitations associated with this review. First, the inclusion of studies that are published in English only introduces a form of language bias. Such a limitation is especially relevant given the cultural contexts and adaptation of instruments used in the assessment of caregiver burden. Second, the exclusion of certain types of study, such as unpublished data, may further limit the scope of the review. Despite efforts to conduct a comprehensive search, some relevant studies may still be omitted inadvertently. However, adherence to a rigorous methodology and deployment of a systematic search strategy should minimise the impact of such limitations.

Ethics statements

Patient consent for publication

References

Supplementary materials

  • Supplementary Data

    This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

Footnotes

  • Twitter @JustAnotherRavi

  • Contributors RS conceived the original idea for the study, developed the research questions, designed the methodology and drafted the initial protocol. RS and WZH conducted the literature search, designed and tested the search strategies and identified appropriate quality assessment tools. NL, YWL, PK, LL and AM assisted in finalising the eligibility criteria, data extraction strategy and risk of bias assessment. JC, HRC and JP provided feedback on the protocol drafts related to the methodology, feasibility and analysis plan. G-GT and HRC oversaw the systematic review software selection and planned the data analysis approaches. RS and WZH wrote the initial draft of the manuscript. NL, PK, LL, GY-XT, AM, JC, HRC, GGT and JP reviewed the draft manuscript and provided edits and suggestions to improve the content and presentation. RS and WZH finalised the manuscript based on co-author feedback. All authors approved the final manuscript and agreed to be accountable for the integrity of the work.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Provenance and peer review Not commissioned; externally peer-reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.