D Scholarly Pen

Evaluating the Role of Community Health Worker Interventions on the Physical and Mental Health Outcomes of Older Individuals in the United Kingdom: A Quantitative Structured Literature Review

This dissertation is submitted in partial fulfilment of the requirements for the degree of Master of Science in Public Health from
Glasgow Caledonian University

This dissertation/project is my own original work and has not been submitted
elsewhere in fulfilment of the requirements of this or any other award
ACKNOWLEDGEMENT
I would like to express my heartfelt appreciation and reverence to everyone who contributed to and encouraged the completion of my dissertation. This work would not have been possible without their guidance, encouragement, and support.
First of all, I would want to extend my heartfelt gratitude to my supervisor, Dr Ben Parkinson, for his unwavering support and invaluable guidance during my dissertation journey. Because of your expertise, persistence, perceptive criticism, devotion, and advice, this project has been considerably impacted and enhanced.
I am grateful to my family and friends for their unwavering encouragement, inspiration, and patience during this academic journey. Their unfailing belief in myself has aided my resilience and self-confidence. I feel extremely fortunate to have their support.
I would also like to recognise the greater educational community, whose ideas and research served as the foundation for this dissertation. Their dedication to improving knowledge in their specific disciplines influenced the path of this study.
Finally, I want to express my heartfelt gratitude to everyone who helped make this dissertation come to fruition, no matter how little their contribution. I am glad for the opportunity to have worked on this project with your guidance, direction, and support.

ABSTRACT
The need for efficient interventions to improve the well-being of older people has grown more important in light of the world's population's growing aging. This study includes a well-organized assessment of the literature that investigates how personalized interventions affect senior citizens' cognitive benefits, physical health, and overall quality of life. The research provides a thorough overview of tactics intended to enhance the overall well-being of older adults by analyzing six carefully chosen studies, including works by Charlesworth et al. (2016), Mountain et al. (2017), Woods et al. (2016), Morton et al. (2018), Mountain et al. (2018), and Adams et al. (2018).
The studies show how effective different interventions can be when they are specifically designed to meet the special needs of older people. Horticulture therapy, intergenerational activities, mindfulness meditation, physical activity programs, and cognitive training were all included in the interventions. Community Health Workers (CHWs) played a crucial intermediary role in these initiatives, offering individualized advice and support all throughout. While physical activity interventions produced improved physical health indicators and overall quality of life, cognitive training programs showed improvements in cognitive functioning. Overall well-being was aided by psychological improvements in areas including emotional stability, reduced stress, and enhanced social interaction.
This synthesis acknowledges the complexities of well-being in later life while echoing established literature and emphasizing person-centered care. This study emphasizes the effectiveness of interventions like cognitive training, physical activity, mindfulness, and CHW-based techniques by correlating with prior studies. In addition to increasing the conversation on healthy aging and providing a road map for enhancing older people's well-being in the face of demographic change, the findings have implications for policy-making and practical implementation.

Table of Contents
ACKNOWLEDGEMENT 2
ABSTRACT 3
CHAPTER ONE 9
INTRODUCTION 9
1.1 Introduction 9
1.1 Background 12
1.1.1 CHWs in Older Adults Care 12
1.1.2 Role of CHWs in Older Adults Care 13
1.1.3 Impact of CHW Interventions on Physical and Mental Health 13
1.1.4 Current Research and Limitations 14
1.2 Review Gaps and Justification 15
1.5 Review Questions 17
CHAPTER TWO 18
METHODOLOGY 18
2.1 Introduction 18
2.2 Rationale and Review Question 18
2.2.1 Review Question 18
2.2.2 Review Design 18
2.2.3 Review Design 19
2.3 Search Strategy 20
2.3.1 Databases 20
2.3.2 Keywords/Boolean Operators 20
2.3.3 Delimiters 22
2.3.4 Inclusion and Exclusion Criteria 22
2.3.5 Identifying Eligible Studies 24
2.3.6 Data Management/Storage 24
2.4 Data analysis and synthesis 24
2.4.1 Data Extraction 24
2.4.2 Methodological Quality Assessment 25
2.4.3 Data Synthesis 26
2.5 Reporting 27
2.6 Dissemination 28
CHAPTER THREE 29
RESULTS 29
3.1 Study Selection 29
3.2 Study Characteristics 31
3.3 Study Design 32
3.4 Sample Size 33
3.5 Interventions 34
3.6 Outcome Measures 36
3.6.1 Cognitive Benefits and Physical Well-being 36
3.6.2 Quality of Life 37
3.6.3 Improvements in Well-being 38
3.6.4 Role of Community Health Workers 40
3.7 Similarities and Differences between Studies 41
3.8 Result of Methodological Quality Assessment 42
3.8.1 Group Randomisation 44
3.8.2 Selection Bias and Sampling 44
3.8.3 Observer Bias 45
3.8.4 Attrition Bias and Sample Size 46
3.8.5 Performance Bias and Data Collection 48
3.8.6 Analytical Approach Adopted 49
3.8.7 Narrative Synthesis 49
CHAPTER FOUR 52
DISCUSSIONS 52
4.1 Overview of Structured Literature Review (SLR) Findings 52
4.2 Comparison of Structured Literature Review (SLR) Findings with Current Knowledge Base 52
4.2.1 Cognitive Benefits and Physical Well-being 52
4.2.2 Quality of Life Enhancement 53
4.2.3 Comparing with Comprehensive Programs 53
4.3 Methodological Quality and Deficits 54
4.4 Strengths of the SLR 55
4.5 Limitations of the SLR 55
4.6 Implications for Policy and Practice 56
CHAPTER FIVE 59
CONCLUSION 59
REFERENCES 62
APPENDICES 79
Appendix 1: Search Results 79
Appendix 2: Data Extraction Form 80
Appendix 3: CASP RCT Checklist Tool 81

Table of Figures
Figure 1: PRISMA Flow Diagram (Page et al., 2021). 30

List of Tables
Table 1: Search String 20
Table 2: Inclusion and Exclusion Criteria 21
Table 3: Study Characteristics 30
Table 4: Summary of Participants 32
Table 5: Interventions 33
Table 6: Physical and Cognitive Outcomes 36
Table 7: Quality of Life Outcomes 37
Table 8: Improvements in Well-Being 38
Table 9: Similarities and Differences between Studies 40
Table 10: Methodological Quality Assessment 41
Table 11: Attrition Bias 46

CHAPTER ONE
INTRODUCTION
1.1 Introduction
In healthcare systems all around the world, community health workers (CHWs) are essential (Agarwal et al., 2019). In the United Kingdom, community health workers (CHWs) refer to a wide range of specialists who provide services in various locations, such as people's homes, community clinics, and educational institutions (Hartzler et al., 2018). They frequently serve children, older adults, persons with chronic illnesses, and people nearing the end of their lives. Adult community nurses, long-term condition specialists, therapists, and organisations that offer preventative services, including clinics for sexual health and smoking cessation, are a few examples of CHWs (e Mello et al., 2023). They also include school nursing and other child health services, including health visits. Several types of Community Health Workers (CHWs) in the UK focus on mental health support for older adults (Hodges et al., 2023). These involve, more specifically, mental health nurses who provide specialised care and social workers who offer support and resources (Hodges et al., 2023).
CHWs link communities and healthcare practitioners significantly where access to healthcare services is restricted or difficult (Hartzler et al., 2018). Since CHWs are frequently locals, they can recognise and address these communities' particular health needs and issues (Ingram et al., 2008). The importance of CHWs increases when caring for older adults aged 60 and above, as stated by the World Health Organisation (2022). The senior population frequently struggles with various health difficulties, such as chronic illnesses, physical impairments, and mental health issues (Pel-Little et al., 2021). Multimorbidity, or the co-existence of many medical diseases in one person, is a problem that frequently affects older adults (Khan et al., 2022). This might include physical limitations like poor hearing or movement, chronic illnesses like diabetes and heart disease, and mental health difficulties like depression or dementia (Khan et al., 2022). The interactions and compounding of these disorders often complicate treatment and management. Multimorbidity's complexity necessitates thorough, coordinated care, a significant problem for global healthcare systems (Khan et al., 2022). It emphasises the necessity for comprehensive strategies considering all of an aged person's health demands.
CHWs can effectively provide the ongoing care and assistance needed to manage these health concerns. Older people's health outcomes can be considerably improved by their help with duties including medication management, health education, and care coordination (Pereira et al., 2022). The role of CHWs in providing care for older adults is exciting in the United Kingdom (Hodges et al., 2023). The proportion of adults 65 and older has increased from 15% in 1985 to 18% in 2015 and is expected to reach 24% by 2045, indicating that the UK has an ageing population (Government Office for Science, 2016). This demographic transition creates severe issues for the healthcare system, mainly overseeing older people's health (National Academies Science Engineering Medicine, 2023). By providing care and support to older people in their homes and communities, CHWs may play a significant role in resolving these issues.
The impact of CHW interventions (such as direct Care like primary medical care and mental health counselling) on the mental health of older people in the UK requires further study despite the potential benefits of these programmes (Hodges et al., 2023). By performing a quantitative structured literature review to assess the impact of CHW interventions on the outcomes for older people in the UK mental health, this study intends to close this gap. This study is timely and pertinent since it can offer helpful information that will help to enhance healthcare practises and policies, which will benefit the ageing population in the UK by enhancing their mental health and quality of life using community care.
The healthcare system has significant challenges due to this demographic transformation, highlighted by the Government Office for Science, notably in providing adequate care for older adults. In the UK, there are many facets to caring for older adults, including home care, residential care, and hospital care (Abdi et al., 2019). In the United Kingdom (UK), the older adult population is principally served by the National Health Service (NHS) and social care organisations (NHS England, 2016). Nevertheless, this system faces several challenges, including increased demand, a need for healthcare experts, and limited resources (NHS England, 2016). The complex healthcare needs of older individuals, who usually have several chronic illnesses and require continual assistance and care, are even more challenging (Kuluski et al., 2017).
These days, community health workers (CHWs) are essential medical workforce members (Mayfield-Johnson et al., 2020). CHWs offer various services, such as health education, preventive care, and assistance in managing chronic diseases (Esperat et al., 2023). Due to their ability to provide care in people's homes and for the local community, they are ideally adapted to assist the ageing population. CHWs can boost the standard of care provided, expand access to care, and alleviate the burden on other healthcare sectors (Greenlee et al., 2023). However, Baker and Clark (2020) posit that many older people in the UK struggle with physical and mental health.
Physical health problems that plague older people regularly, such as diabetes, heart disease, and arthritis, greatly lower their quality of life and call for ongoing management (Booker and Content, 2020). Mental health concerns, such as dementia, depression, and anxiety, are more prevalent among older adults due to the stigma attached to mental health and the barriers to receiving the necessary care (Lavingia et al., 2020). Multimorbidity in this context describes how seniors have physical and mental health disorders, such as dementia, depression, and anxiety. People may be deterred from receiving the necessary therapy because of the stigma around mental health, which can worsen these conditions (Kuluski et al., 2017). The relationship between stigma and multimorbidity is complex, though further research is needed (Suls et al., 2019). While stigma may function as a deterrent to receiving care, other aspects such as service accessibility, socioeconomic status, and the quality of care must also be considered (Nyblade et al., 2019).
Addressing these challenges with physical and mental health requires the work of CHWs (Johnson et al., 2022). According to Yao et al. (2023), they can provide tailored care, assist patients in controlling their illnesses, and make it easier for people to access non-traditional healthcare options. To best meet each person's requirements and circumstances, CHWs offer customised care (Johnson et al., 2022). The management of chronic illnesses, encouraging the patients' mental health, and helping them with daily duties are a few examples of this. CHWs also act as a link between the patient population and the more significant healthcare industry (Lloyd et al., 2020). Patients can work with them to coordinate with numerous healthcare professionals, negotiate challenging medical procedures, and access extra resources as necessary (Johnson et al., 2022).
Furthermore, because they frequently have a thorough grasp of the communities they work with, CHWs can address social and cultural issues that may impact health (Colvin et al., 2021). As a result, they have a diverse role that includes direct care, advocacy, education, and coordination (Colvin et al., 2021). More research is needed to fully understand how CHW treatments have impacted older individuals' physical and mental health outcomes in the UK. This study aims to fill this knowledge gap and greatly aid in developing proper plans for enhancing senior care in the UK.
1.1 Background
1.1.1 CHWs in Older Adults Care
The breadth and diversity of the literature on CHWs in aged care reflect the multidimensional role that CHWs play in global healthcare systems. Numerous facets of CHW interventions have been studied, such as their duties, functions, training, and service offerings. The unique function of CHWs as bridges between medical services and communities is a recurrent theme in the literature. CHWs are frequently better suited to recognise and address these groups' particular health problems because they are locals in their areas (Lewin et al., 2021; Glenton et al., 2021). This is especially important while caring for older adults because CHWs may offer tailored support and care to senior citizens in their homes and communities.
The effectiveness of CHW interventions in enhancing health outcomes and lowering healthcare expenditures has been shown in numerous research (Knowles et al., 2023; Berini et al., 2022). As an illustration, it has been demonstrated that CHWs improve older adults’ patients' access to preventative care, encourage medication adherence, and lower the number of hospital admissions (Knowles et al., 2023; Sokan et al., 2022). Less is known regarding the impact of CHW interventions on health outcomes, especially those that pertain to physical and mental health. Because of this, this study aims to close a gap in the literature by conducting more in-depth research in this field.
1.1.2 Role of CHWs in Older Adults Care
Numerous studies have been conducted on the function of Community Health Workers (CHWs) in providing care for the elderly. Assisting older folks with their emotional needs, educating them about their health, and managing medicines are just a few of the duties that CHWs typically carry out (Hodges et al., 2023; Glenton et al., 2021).
A thorough evaluation by Kennedy et al. (2021) found that CHWs can aid older people with chronic diseases manage their symptoms. In addition to teaching patients about their conditions, CHWs can provide them with lifestyle adjustment advice and support so they can adhere to treatment plans. They can also keep track of symptoms and inform medical staff of any changes (Hartzler et al., 2018). Additionally, CHWs can offer social and emotional support, enhancing one's mental health and quality of life (Mistry et al., 2021). This is crucial for older people with social isolation or mental health issues. However, the effectiveness of CHWs largely depends on their training and expertise. They may not provide the most effective care or advice if not adequately trained.
Despite this challenge, as stated by Kennedy et al. (2021), older people with chronic illnesses benefited from CHW interventions regarding their health outcomes. The study, however, was primarily concerned with a particular population group, so its conclusions might not apply to other contexts. The usefulness of CHW interventions in enhancing older patients' medication adherence was also emphasised by Hodges et al. (2023). More high-quality research is required to support these findings, as the review also pointed out that the included studies' quality could have been more consistent.
These findings demonstrate that CHWs can be crucial in caring for older adults. More research is necessary to completely comprehend the effect of CHW interventions on senior people's health, as the data is only nascent.
1.1.3 Impact of CHW Interventions on Physical and Mental Health
Research has explicitly studied the effects of Community Health Worker (CHW) treatments on older people's physical and mental health. For instance, a study by Mbuthia et al. (2022) demonstrated that CHW interventions significantly improved blood pressure control in older hypertensive people. The study included a total of 10 randomised controlled trials with 4,230 participants. The mean age of the participants was 60.5 years. The study found that CHW interventions significantly reduced systolic blood pressure (SBP) by -4.22 mmHg (95% CI: -6.35, -2.09) and diastolic blood pressure (DBP) by -2.16 mmHg (95% CI: -3.36, -0.96). The study also found that CHW interventions significantly improved blood pressure control (RR 1.22, 95% CI: 1.07, 1.39). The subgroup analysis showed that CHW interventions were more effective in studies where CHWs received training (SBP: -4.59 mmHg, 95% CI: -6.95, -2.23; DBP: -2.36 mmHg, 95% CI: -3.71, -1.01). However, the study's small sample size and brief follow-up period were its main limitations, which might impact how generalisable its findings are.
Kennedy et al.'s (2021) assessment of the literature on mental health discovered that CHW-led interventions helped lessen depressive symptoms in older people. The review highlighted CHWs' ability to provide mental health therapies in community settings. The specific interventions led by CHWs varied across the studies included in the review. However, the review does not provide detailed information about the specific interventions used in each study. The interventions generally involved CHWs providing support and care to older adults with complex health needs, including various health conditions and challenges.
However, the review pointed out that most of the studies it did include were conducted in low- and middle-income nations. As a result, its conclusions might not be directly applicable to wealthy nations like the UK. These studies indicate that older people's physical and mental health can benefit from CHW therapies. More high-quality research is required to validate these results and comprehend the mechanisms through which CHW treatments improve health outcomes, as available evidence still needs to be provided.
1.1.4 Current Research and Limitations
The significant variation in approaches used in the examined studies reflects the diversity of research in this area. Much research uses quantitative techniques to determine how CHW interventions affect health outcomes, including cohort studies and randomised controlled trials. These techniques offer solid proof of interventions' efficacy, but they could ignore the complexities and subtleties of CHW interventions (Lockwood et al., 2019). For instance, Quantitative research requires standardisation to ensure the intervention is applied consistently across all participants (Lockwood et al., 2019). However, CHW interventions are often tailored to the individual needs and circumstances of each patient, which can vary widely (Yan et al., 2022). This individualised approach can be challenging to capture in a standardised research design. Also, CHW interventions often aim to improve various outcomes, including physical health, mental health, social well-being, and healthcare access (Yakubu et al., 2022). Some of these outcomes, particularly those related to social well-being and quality of life, can be complex and multifaceted, making them challenging to measure accurately with quantitative methods.
The evaluated research indicates that Community Health Worker (CHW) interventions can benefit older people's physical and emotional health. The significant findings include improving chronic disease management, medication adherence, and mental health outcomes. These results show the CHWs' ability to improve aged care and meet the health demands of this population.
However, these studies by Mbuthia et al. (2022) and Kennedy et al. (2021) also have some drawbacks. The generalizability of such research may be constrained by the use of small sample numbers, brief follow-up times, or specialised demographic groups. Additionally, many studies need to adequately control for confounding variables, which could skew the results. A noteworthy gap in the literature is the absence of high-quality studies explicitly looking at the effect of CHW interventions on the physical and mental health of older adults in the UK. These restrictions highlight the need for more thorough and narrowly focused research.
1.2 Review Gaps and Justification
CHWs offer a variety of interventions that are adapted to the needs of older people. These include care coordination, medication management, health education, and preventive care (World Health Organisation, 2020). According to Finlay et al. (2021), CHWs can significantly improve older people's mental health and well-being by providing them emotional support and companionship.
A study by Ellis et al. (2020) found that measures of chronic illness management, such as blood pressure control or diabetes management, are frequently included in physical health outcomes. Many mental health outcomes concentrate on anxiety or depressive symptoms. However, some studies also track more general outcomes, such as quality of life or medical use (Raghupathi et al., 2020).
Hodges et al. (2023) state that CHWs can enhance older adults' physical and mental health. However, the success of CHW interventions appears to depend on several variables, including the kinds of interventions offered, the training and support received by CHWs, and the characteristics of the older people getting care, according to conflicting findings (Hodges et al., 2023).
Although the above assertions shed essential information on the function of CHWs in providing care for older adults, they also draw attention to significant knowledge gaps (Johnson et al., 2022). For instance, more studies must examine the precise processes through which CHW interventions enhance health outcomes. Additionally, most research concentrates on the person's health outcomes, paying little attention to the broader effects of CHW treatments on healthcare systems or communities (Jack et al., 2017). As most studies only have short follow-up times, more significant research is needed to examine the long-term effects of specific CHW interventions (Kangovi et al., 2018).
Additionally, most studies in the literature focus on low- and middle-income nations, with fewer studies looking at the function of CHWs in high-income nations like the UK (Ahmed et al., 2022). Since only some of the findings apply to the UK setting. As a result, this emphasises the need for additional expert research in this field. Overall, while the literature provides evidence of the potential benefits of CHW interventions in older individuals' care, further research is necessary to fully understand their impact on older adults' physical and mental health (Johnson et al., 2022; Hodges et al., 2023).
The precise mechanisms by which CHW treatments improve health outcomes require further study (Adams et al., 2021). Knowing these elements can help you gain crucial insights into improving the efficacy of CHW interventions. These information gaps underscore the need for more in-depth and rigorous research on the impact of CHW treatments on older individuals' physical and mental health in the UK (Kennedy et al., 2021). The results of this study can be used to develop valuable plans for boosting senior care and satisfying their healthcare needs.
1.5 Review Questions
This study intends to evaluate how CHW interventions have affected older individuals' mental health outcomes in the United Kingdom. Following is the leading review query:
How do Community Health Workers (CHWs) interventions affect the mental health outcomes of older individuals in the United Kingdom?

CHAPTER TWO
METHODOLOGY
2.1 Introduction
This chapter describes the methodology used in this review, thoroughly explaining the organised procedures utilised to respond to the review question. The methodology is essential since it ensures that the review's and the findings' integrity. A thorough overview of the review process will be given in this chapter through a discussion of the review's architecture, search strategy, data management, and data analysis methodologies.
2.2 Rationale and Review Question
2.2.1 Review Question
The review question addressed by this investigation is: "How do Community Health Worker (CHW) interventions affect older adults' mental health outcomes in the United Kingdom?"
2.2.2 Review Design
Through a structured literature review, this review utilises a quantitative methodology. The decision to use a quantitative method is justified since it enables a systematic and impartial investigation of the influence of CHW interventions on mental health outcomes (Han et al., 2018). Quantitative techniques offer quantifiable and numerical statistics demonstrating interventions' efficacy (Mohajan, 2020). The decision to do a structured literature review is warranted since it enables a thorough and organised analysis of the available research, which broadens our understanding of the subject (Paul et al., 2021). Additionally, it makes it possible to spot gaps in the existing body of knowledge, which directs future review initiatives (Paul et al., 2021).
Given that outcomes related to mental health may be evaluated and analysed objectively, this review takes a quantitative approach (Kohne et al., 2023). In line with positivist paradigm principles, it pursues knowledge by methodical data collecting and numerical analysis (Park et al., 2020). A structured literature review methodology is used to assess the body of research and generate thorough and impartial insights into the influence of CHW interventions on mental health outcomes. This approach enables the identification of knowledge gaps, which directs future research efforts and aids in the growth of evidence-based practices in mental health interventions (Hempel et al., 2019).
2.2.3 Review Design
This study's review design used a structured literature review with a particular emphasis on quantitative research. For several reasons, this design was chosen. To minimise bias and ensure the review can be replicated, it searches for and chooses studies by an established process (Jahan et al., 2016). This is crucial in the health review field, where solid, trustworthy evidence is required. Because it explicitly emphasises quantitative studies, the structured literature review design stands out from others, such as narrative or systematic reviews (Noble and Smith, 2021). Contrary to narrative reviews, which use a more arbitrary and qualitative manner of summarising literature, the structured literature review uses a strict and repeatable methodology for locating, choosing, and evaluating quantitative research (Xiao and Watson, 2017). This approach prioritises quantitative data and statistical analysis, enabling a more impartial assessment of the effect of CHW interventions on mental health outcomes.
Second, the review question's emphasis on quantitative studies is consistent with its goal to evaluate the influence of CHW therapies on mental health outcomes in older persons (Kennedy et al., 2021). Data from quantitative research, such as RCTs and cross-sectional studies, can be utilised to calculate the effect of CHW interventions on the outcomes of older persons' mental health (Setia, 2016). RCTs are considered the gold standard in health research due to their ability to demonstrate cause-effect relationships and control for confounding variables (Curley and Lin, 2020). Cross-sectional studies, on the other hand, provide a snapshot of the population at a specific point in time, offering valuable insights into the current body of knowledge (Setia, 2016).
Transparent methods, a scientific approach, and replicability are fundamental in a well-conducted literature review, especially in health research (Smith et al., 2021). Transparent methods involve explicitly outlining the review process, promoting credibility. A scientific approach employs rigorous principles, ensuring objectivity in study selection and analysis (Sikorski, 2021). Replicability allows other researchers to verify findings independently, bolstering the review's reliability (Plesser, 2018). A structured literature review focusing on quantitative studies provides precise details of searches, inclusion criteria, and data analysis. Quantitative synthesis methods like meta-analysis assess study quality using consistent criteria (Pigott and Polanin, 2019). The review gains credibility by providing insightful data on the efficacy of CHWs and interventions for mental health.
2.3 Search Strategy
2.3.1 Databases
For this analysis, databases are crucial because they give access to peer-reviewed research about CHW interventions and mental health outcomes. By ensuring a thorough and organised literature search through databases, the review can be based on various reliable and pertinent quantitative studies (Bramer et al., 2018). The following databases were chosen for the academic literature search: PubMed, PsycINFO, and CINAHL (Oermann et al., 2021). A helpful tool for health-related review, PubMed is a comprehensive database that includes information on preclinical sciences, nursing, dentistry, veterinary medicine, and healthcare systems (Rodgers and Ritskes-Hoitinga, 2021). The American Psychological Association's PsycINFO database, which gives users access to material pertinent to mental health outcomes, is a crucial resource for psychological, social, and behavioural sciences (Townsend et al., 2023). According to Behrend (2020), CINAHL (Cumulative Index to Nursing and Allied Health Literature) is the most complete nursing and allied health literature repository. The selection of these databases guarantees that the research on CHW interventions and outcomes for older persons' mental health is broadly and multidisciplinaryly covered (See Appendix 1). Since some studies may have been published in less accessible or non-indexed places, it is doubtful that all research on CHW therapies and outcomes for older persons' mental health will be discovered. The inclusivity of the review may also be constrained by language hurdles and publishing bias, necessitating the recognition of any potential gaps in the literature (Mengist et al., 2020).
2.3.2 Keywords/Boolean Operators
To create research questions and choose keywords for literature searches, the PICO framework is employed (Eriksen and Frandsen, 2018). PICO stands for the following in this analysis of CHW interventions and outcomes for mental health in older individuals:
P - Population: Older adults in United Kingdom
I - Intervention: Community Health Worker (CHW) interventions
C - Comparison: usual care and different intervention
O - Outcome: Physical and Mental health outcomes
Applying the PICO framework ensures that the search is concentrated on pertinent studies relating to CHW interventions and mental health outcomes in older individuals, providing a more focused and efficient literature review approach.
In order to achieve a thorough search, the search technique used keywords, Boolean operators, and subject headers. The search string is presented in Table 1.
Table 1: Search String

P
I
C
O

Search Expressions Combined With
Older adults in United Kingdom

AND
Community Health Worker (CHW) Interventions

AND
Usual care and different intervention

AND
Physical and Mental health outcomes

AND

OR
OR
OR
OR
OR

Older adults
Elderly*
Geriatric
United Kingdom
1 OR 2 OR 3 OR 4
Community Health Worker
CHW
Health Worker*
6 OR 7 OR 8

Mental health
Depression
Anxiety
Psychological well-being
10 OR 11 OR 12 OR 13

MeSH (Medical Subject headers) phrases were used as subject headers to further the search. As an illustration, the word "Mental Health" from MeSH was used to refer to various mental health-related topics. This combination made a thorough and narrowly focused search of the literature possible (Salvador-Oliván et al., 2019).
Truncation was employed as a search tool to make sure that all variants of a keyword that were relevant to the search were included (CSU, 2023). The keywords "elder*" were used, for instance, to capture "elderly", "elder", "elders", and "elderly's". This method expands the search and guarantees that all pertinent literature is included (Salvador-Oliván et al., 2019).
2.3.3 Delimiters
This review used language and time period as delimiters (Bulthuis et al., 2020). Due to language proficiency and guaranteeing that the studies were understood completely, only papers published in English were included (Dobrescu et al., 2020). This standard delimiter in review allows for a more manageable pool of studies. Furthermore, limiting the study to English publications was feasible for an unfunded dissertation, as it reduced translation costs and time (Nowell et al., 2017). However, it might have introduced language bias and excluded valuable non-English literature (Jackson and Kuriyama, 2019). To mitigate risks, consulting experts and conducting supplementary searches for non-English studies could enhance the review's comprehensiveness (Gusenbauer, M. and Haddaway, 2020). The time period was set from 2013 to the present to ensure the relevance and currency of the review. Healthcare practices and policies, including the role and training of Community Health Workers, have evolved significantly over the past decade. Therefore, focusing on this time period ensures the review reflects current practices and knowledge in the field (Luft et al., 2020).
2.3.4 Inclusion and Exclusion Criteria
Table 2: Inclusion and Exclusion Criteria
Criteria
Inclusion
Exclusion

Population
older adults (aged 60 and above) in the United Kingdom.
Studies not involving older adults (aged 60 and above) or not based in the United Kingdom.

Intervention
interventions delivered by Community Health Workers (CHWs).
Studies not examining interventions delivered by CHWs.

Comparison
of usual care and different intervention
Studies not measuring mental health outcomes.

Outcome
mental health outcomes (e.g., depression, anxiety, quality of life).

Study Design
Randomised controlled trials (RCTs) and cross-sectional studies.
Qualitative studies, case reports, reviews, and opinion pieces: grey literature, unpublished thesis/dissertations.

Language
English.
Studies not published in English.

Time Period
2013 to the present.
Studies published before 2013.

Table 2 shows the inclusion and exclusion criteria of the studies. The inclusion criteria ensure that the selected studies are directly relevant to the review question, focusing on the target population (older adults in the UK), intervention (CHW-delivered), and outcome (mental health). The exclusion criteria ensure the relevance and understandability of the findings by excluding research with less reliable study designs and studies that do not adhere to the language and time period standards, helping to maintain the methodological rigour of the review (Patino and Ferreira, 2018).
The review design includes a comprehensive search of quantitative studies, including cross-sectional studies and randomised controlled trials (RCTs). RCTs are preferred because they have high evidence, show cause-and-effect correlations, and account for confounding factors (Spieth et al., 2016). Cross-sectional studies are included because they offer a picture of the population at a particular period and provide essential insights into the present situation (Setia, 2016). This combination of research methods enables a thorough understanding of how CHW interventions affect older individuals' mental health.
2.3.5 Identifying Eligible Studies
According to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, only eligible studies were chosen (Page et al., 2021). The titles and abstracts of each study retrieved from the database were initially used to filter the results. Research was then obtained for full-text analysis of studies that fit the inclusion criteria (Bramer et al., 2017). Studies were further evaluated for eligibility based on the specific inclusion and exclusion criteria throughout the full-text evaluation. A PRISMA flowchart was used to record every step of the procedure, including how many studies were screened, determined eligible, and included in the review (Page et al., 2021).
2.3.6 Data Management/Storage
To guarantee that the acquired data is organised and accessible, data management and storage are essential components of the review process (Surkis and Read, 2015). Data administration in this work was accomplished using RefWorks, a reference management programme (Castillo et al., 2022). RefWorks enables effective management and archiving of references, full-text articles, and other information gathered during the literature search (Castillo et al., 2022). Additionally, it makes it easier to eliminate duplicate entries, a prevalent problem in structured reviews. RefWorks ensures the data is organised and stored securely, making the review process easier (Castillo et al., 2022). The review procedure will be fully transparent and reproducible, and an appendix will be provided.
2.4 Data analysis and synthesis
2.4.1 Data Extraction
A structured literature review must include data extraction, which entails gathering pertinent information from the chosen research (Lefebvre et al., 2019). A data extraction form particular to this review was created and utilised to standardise the procedure and guarantee that all relevant data was recorded (See Appendix 2). (Xu et al., 2022) The form had sections for study characteristics (e.g., authors, year of publication, location), participant characteristics (e.g., age, gender, health status), details of the CHW intervention (e.g., type, duration, frequency), details of the comparison group, mental health outcomes measured, and key findings.
After carefully reading each study, the pertinent information was retrieved and entered into the form. A review-specific data extraction form has several benefits. It ensures that the same data is gathered from every investigation, which is necessary for comparing and synthesising the findings (Büchter et al., 2020). When dealing with much research, it might be constructive to maintain a methodical and organised approach to data extraction (Snyder, 2019).
This strategy, nevertheless, also has certain drawbacks. It might only partially represent some of the subtleties and complexities of the research (Da, 2019), especially those that have to do with the setting and ex*****on of the CHW treatments. It also depends on how well and thoroughly the reporting in the initial trials is done. To lessen the impact of these restrictions, the data extraction form was made as thorough as possible, and any uncertainties or data gaps were documented for later consideration in the analysis and interpretation of the findings (Schmidt et al., 2021). The TIDIER framework will enhance data-gathering by methodically extracting crucial information from studies (Li et al., 2019). It helps with the screening process by identifying pertinent research, collecting data on study design and intervention, and standardising the recording of critical findings. As a result, the organised literature review is more effective, transparent, and replicable (Cotterill et al., 2018).
2.4.2 Methodological Quality Assessment
An essential step in a structured literature review is evaluating the included studies' methodology (Ma et al., 2020). The Randomised Controlled Trial (RCT) tool from the Critical Appraisal Skills Programme (CASP) is a well-known and systematic method for evaluating quantitative research studies' methodological quality and validity. It offers a methodical framework for assessing several facets of RCTs, assisting researchers, practitioners, and readers in making educated decisions on the validity and dependability of the study results (Harrison et al., 2017).
The structured literature review used to examine the studies considered for this evaluation employed the CASP RCT tool. This was to ensure a comprehensive understanding of the advantages and disadvantages of the methodological approaches of the studies and the overall rigor of their research designs (Munthe-Kaas et al., 2019). The CASP RCT tool encompasses different questions that provide a framework to assess the different aspects of an RCT investigation which includes the study design, randomization process, blinding, data collection and result interpretation (See Appendix 3). Each question scrutinizes each research in relation to the factors that influence its internal and external validity, as explained by Long et al. (2020).
A consistent and systematic evaluation of each trial was made possible due to the adoption of the CASP RCT tool in this review (Aveyard and Bradbury-Jones, 2019). Following Munn et al. (2018) approach, this review sought to objectively assess different methodological elements by answering the checklist question for each manuscript. This included emphasising potential biases, strengths, and weaknesses. The review procedure was made more systematic and thorough with the assistance of the CASP RCT tool (Harrison et al., 2017). It enabled the reviewer to concentrate on crucial elements of the planning, ex*****on, and reporting of each study, assisting in detecting potential biases and methodological faults (See Table 3.6). The review sought to offer an unbiased and transparent evaluation of the quality and validity of the included quantitative studies by methodically assessing each study against the CASP criteria (Long et al., 2020).
2.4.3 Data Synthesis
Data synthesis combines the results from various studies to produce a comprehensive picture of the review subject (Stern et al., 2021). A meta-analytic technique was initially thought of because of the quantitative aspect of this review. The ability to calculate pooled effect estimates by meta-analysis (Sera et al., 2019) enables a quantitative summary of the influence of CHW interventions on mental health outcomes in older individuals. However, the choice to perform a narrative synthesis was made due to the projected heterogeneity in the interventions, outcomes measured, and research designs anticipated in the literature (Xu et al., 2022).
The synthesis findings are summarised and explained using words and text in a narrative synthesis (Rai et al., 2020). It is conducive in cases where studies are too dissimilar to combine statistically, as in this review. This review's narrative synthesis adhered to the recommendations made by the Centre for Reviews and Dissemination (Campbell et al., 2018). It involves four essential components: formulating a hypothesis of the intervention's effectiveness—how, why, and for whom—exploring relationships in the data, generating a preliminary synthesis of the findings of included studies and evaluating the synthesis's robustness (Campbell et al., 2019).
By choosing a narrative synthesis, the data can be explored flexibly and thoroughly, embracing the predicted variation in the literature (Xiao and Watson, 2017). It does, however, have some drawbacks. It is primarily descriptive and does not offer a single summary measure of effect, as would be the case with a meta-analysis (Campbell et al., 2019). Additionally, the synthesis relies on the reviewers' judgement, which may introduce subjectivity. In order to overcome these drawbacks, the synthesis was carried out methodically and openly, adhering to predetermined instructions and recording all decisions and actions (Xiao and Watson, 2017).
2.5 Reporting
According to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria (Page et al., 2021), the findings of this review will be presented. The PRISMA guidelines offer a standardised format for presenting systematic or structured reviews, allowing readers to evaluate the review's calibre and repeatability (Snyder, 2019).
The PRISMA flowchart will represent the study selection procedure, showing the number of studies screened, evaluated for eligibility, and included in the review (See picture 1). In a table (See table 3.1), the characteristics of the included studies, including study design, participant characteristics, intervention details, mental health outcomes measured, and significant findings, will be summarised.
A Randomised Controlled Trial (RCT) methodology developed by The Critical Appraisal Skills Programme (CASP) will also be used to provide the findings of the methodological quality evaluation (Long et al., 2020). A narrative method will be employed for the data synthesis to summarise and explain the results of the included studies. Themes and patterns uncovered in the literature will be addressed, along with any connections and contradictions discovered (Rai et al., 2020).
2.6 Dissemination
The review's conclusions will be distributed through several media to reach various audiences. The review will be published in a peer-reviewed publication specialising in public health or interventions in the mental health field (Brownson et al., 2018). This guarantees that the review receives a close expert inspection and adds to the body of knowledge (Tawfik et al., 2019).
The main conclusions of the review will be summarised and distributed to policymakers and healthcare professionals in addition to the scholarly publication. For non-academic audiences, this summary will be presented in a way that is simple to read and understand to guide practice and decision-making (Brownson et al., 2018).
Additionally, the findings will be shared with the academic and professional sectors by presenting the results at pertinent conferences and seminars (Helmer et al., 2023). It will be possible to network, collaborate, and have dialogues with other researchers and industry stakeholders by presenting the review's findings at conferences (Edwards, 2015).
Overall, a thorough reporting and dissemination strategy will guarantee that the findings of this structured literature analysis are publicly available and contribute to effective mental health interventions for older persons in the United Kingdom (Helmer et al., 2023).

CHAPTER THREE
RESULTS
3.1 Study Selection
The combined database search resulted in 20 articles, and five duplicates were identified and eliminated in the RefWorks data management system. After screening the titles and abstracts of the remaining 15 articles, five were found to need to be revised. After reading the full text of the remaining ten articles, four still needed to meet the criteria for inclusion. One of these studies appeared from its abstract to be suitable (Gabbay et al., 2013) but needed to be in full-text form, which was requested by the research authors without success. These studies were therefore not included. Six studies were included in the review (Charlesworth et al., 2016; Mountain et al., 2017; Woods et al., 2016; Morton et al., 2018; Mountain et al., 2014; Adams et al., 2018). Figure 1 shows the PRISMA diagram that accounts for this study selection process.

Figure 1: PRISMA Flow Diagram (Page et al., 2021).

3.2 Study Characteristics
Table 3: Study Characteristics
S/NO
Authors & Country
Number Enrolled
Diagnosis
Approach
Intervention (Delivery)
Control
Follow-up
Data Collection

1.
Adams et al. (2018)
64
Visually Impaired Older People
Randomised Controlled Trial
Community-Based Group Exercise
Control Group
6 months
Interviews, Assessments using the Short Form Falls Efficacy Scale

2.
Charlesworth et al. (2016)
300 pairs of carers and people with dementia
People with Dementia & Family Carers
Factorial Pragmatic Randomized Trial
Peer Support & Reminiscence Thera