1.1 Background and Rationale

As the number of people living with dementia (PLWD) in the United Kingdom continues to rise [1], so too does the number of carers of PLWD navigating a range of complex needs, including medical, emotional, social and practical challenges, frequently exacerbated by social isolation and barriers to accessing support [2, 3]. Post-diagnostic support (PDS) is essential for improving the quality of life for PLWD and carers of PLWD [4]. However, this support is often hindered by a lack of health system organisation and inequalities in its provision [4]. Addressing the PDS needs of carers of PLWD requires a comprehensive approach that incorporates medical, psychological and social support. Social prescribing (SP) is one such approach, addressing the non-clinical needs of carers of PLWD through community-based interventions typically provided by voluntary and community groups, such as support groups, arts and crafts activities, and physical activities [5, 6]. Evidence suggests SP can promote social engagement, reduce loneliness and enhance overall well-being [5, 7, 8]. However, integrating SP into dementia care is challenging due to inconsistent service provision, a lack of implementation guidelines or referral processes, insufficient funding and limited stakeholder alignment on how SP should be instigated or hosted [9-11].

Therefore, a comprehensive systematic review (CISR) to identify, describe and explore how carers of PLWD engage with SP interventions is required to examine the mechanisms, processes and circumstances involved and inform future implementation strategies and improve dementia care outcomes. This paper is Part 2 of a two-part series that reports the mechanisms, processes and outcomes of SP for both PLWD (Part 1) and carers of PLWD (Part 2). The series' results were split due to the differing needs of the two groups and the heterogeneity and breadth of the evidence identified in the original review. This approach enables detailed exploration, interpretation and evaluation of the findings. Part 1 of the two-part series, reporting findings for PLWD, is reported elsewhere and is submitted ‘in press’ [12].

1.2 Operating Definition

Both Part 1 (PLWD) and Part 2 (carers of PLWD) of the CISR define SP as ‘a means for trusted individuals in clinical and community settings to identify non-medical, health-related social needs and connect individuals to non-clinical supports and services within the community by co-producing a social prescription’ [13 (p. 9)]. This definition emphasises two core components: (1) the connector, a trusted individual who provides holistic support and a personalised care plan, and (2) the co-produced care plan, developed in equal partnership to address non-medical health-related needs.

2.1 Data Sources

Multiple electronic databases (MEDLINE, EMBASE, PsycINFO, CINAHL, Scopus and Cochrane/CENTRAL), grey literature sources (EThOS and CORE) and reference lists of included studies were searched.

2.2 Inclusion and Exclusion Criteria

Inclusion and exclusion criteria were based on the PICOTS (Population, Intervention, Context, Outcomes, Timing, Setting) framework, targeting studies involving both PLWD and carers of PLWD who engaged with the core elements of the SP pathway in community settings (see Table S1 in Supporting Information). To address SP complexity and guide screening decisions, a figure representing possible pathways of SP, adapted from Husk et al. [14] in alignment with the working definition set for this review, was used (Figure 1) [12].

2.3 Search Strategy

The search strategy was developed with an academic librarian, who used relevant keywords and database-specific terms for SP and dementia to tailor the search. A sample of the search string carried out in MEDLINE (Ovid) is provided in Supporting Information File S1. The search focused on UK-based studies in English from 1 January 2003 to 15 June 2023 without methodological restrictions.

2.4 Study Selection

After de-duplication in EndNote V.20, citations were imported into Rayyan for screening [15]. Two reviewers (J.M. and S.W.) independently assessed titles, abstracts and full texts, with disagreements resolved by a third reviewer (E.P.).

2.5 Data Extraction

Data relating to PLWD and carers of PLWD were extracted separately into a Microsoft Excel template designed to capture study characteristics and findings related to the review questions. Two authors (J.M. and S.W.) duplicated data extraction on 10% of studies to check accuracy, with adjustments made as necessary.

2.6 Quality Assessment

The Gough's Weight of Evidence (WoE) framework [16] was used to assess study quality. This framework was purposefully selected to appraise studies in this review due to its suitability for assessing diverse types of evidence, including qualitative, quantitative and mixed-methods research. Given the complexity of SP interventions and the varied methodological approaches used in the included studies, a flexible and comprehensive appraisal tool was essential. The Gough (WoE) framework enables a structured evaluation of both methodological quality and relevance to the review questions, supporting a more nuanced synthesis of findings. Its use is well established in systematic reviews that draw on heterogeneous evidence, particularly within health and social care research.

The framework involves scoring studies across three domains: coherence (WoE A), design appropriateness (WoE B) and focus relevance (WoE C). An overall score (WoE D) was calculated for each study. One author (J.M.) performed the assessments, with 20% independently verified by another author (S.W.), which resulted in high agreement between the two reviewers. The quality assessment categorised studies as low, moderate or high quality. Typically, low-quality studies would be excluded a priori; however, a deliberate decision was made not to exclude them from this review. This decision was justified because the existing evidence base specifically addressing SP interventions for carers is diffuse in nature. Excluding lower-quality studies could potentially omit important contextual insights, novel approaches or innovative ideas that are essential for understanding the complexities and nuances of SP interventions. Furthermore, including all quality levels provides a comprehensive and transparent view of the current research landscape, clearly identifies methodological gaps and offers essential guidance for future research, policy development and practice improvements.

2.7 Data Synthesis

During narrative synthesis [17], PLWD data and carer of PLWD data were split and aligned to the review questions. Results were reported descriptively or thematically due to the heterogeneity of the data. This heterogeneity arose from the inclusion of multiple study designs, diverse intervention components, varied outcome measures and differing participant characteristics. Given these variations, a narrative approach allowed for an in-depth descriptive and thematic interpretation of the data, capturing nuances and context-specific insights effectively. The synthesis adhered to the AHRQ and PRISMA-CI guidelines for complex interventions [18, 19]. Specifically, these guidelines provided a structured approach to systematically identify patterns and relationships within the data, ensuring methodological transparency and enhancing the interpretative rigour of the synthesis. Furthermore, narrative synthesis was particularly suitable for addressing research questions where numerical aggregation was not feasible or meaningful due to the varied methodological and conceptual frameworks across studies. It enabled a comprehensive and nuanced understanding of complex phenomena, which is critical in the context of SP interventions for carers of PLWD. This paper reports the data synthesis for carers of PLWD only; the synthesis for PLWD is reported elsewhere [12].

3.1 Characteristics of Included Studies

The 52 included studies on carers of PLWD comprise 41 original articles, 10 project reports and 1 PhD Thesis, using qualitative (n = 32), quantitative (n = 4), mixed-methods (n = 12) and RCT (n = 4) designs. All were conducted in the United Kingdom: UK-wide (n = 7), England (n = 35), Scotland (n = 5), Wales (n = 2), and England and Wales (n = 3), and published between 2005 and 2023. Table 1 summarises the included studies [4, 5, 7, 8, 11, 22-68].

3.2 Heterogeneity, Focus and Nature of Available Evidence

The 52 included studies noted significant heterogeneity in study design, including carer demographics, SP intervention types, comparison groups and outcome measures.

Given the diversity of intervention approaches, outcomes measured and populations studied, conducting a quantitative synthesis was not feasible. Specifically, methodological heterogeneity (e.g., variations in study designs and outcome measurements), clinical heterogeneity (e.g., diverse population characteristics, intervention types and comparator conditions) and a general lack of standardised data necessary for calculating standardised effect sizes posed significant barriers. Attempting a meta-analysis under these conditions could have risked under-representing or misrepresenting the evidence base. Thus, the chosen narrative synthesis approach best accommodates the broad research questions and the diffuse nature of available evidence and ensures a comprehensive representation and meaningful interpretation of existing data.

Due to this heterogeneity, results are presented narratively, descriptively or thematically depending on available evidence. A concise summary of the results is visually represented in the final iteration of the logic model included in this systematic review (see Figure S1 in Supporting Information). Reporting follows the structure of the model, that is, participants, interventions/services, mechanisms, processes, reasons/circumstances and outcomes.

3.3 Participants

Participants refer to carers of PLWD or informants of carers of PLWD. Gender information was reported in 26 of the included studies, with 22 studies reporting exclusively [25, 58] or predominantly [4, 11, 23, 29, 30, 35, 36, 38-44, 47, 53, 59, 60, 63, 64] on female participants. Age was reported in 24 of the included studies, with most (n = 14) reporting ages between 40 and 90 years [11, 23, 29, 30, 35, 36, 39, 41, 43, 47, 48, 55, 56, 59]. The relationship of the carer to the PLWD was reported in 25 of included studies [23-25, 29-32, 35-41, 43, 44, 47-49, 52, 55, 56, 59, 63, 64]: spouses (n = 24), son or daughter (n = 21), grandchild (n = 2), friend (n = 7), sibling (n = 7), daughter or son in law (n = 4), niece/nephew (n = 2), cousin (n = 2), neighbours (n = 1) and other (n = 3). Finally, eight studies reported living arrangements [31, 32, 36, 38, 39, 53, 55, 56], with most carers cohabiting with the PLWD they care for [36, 38, 39, 53, 55, 56].

3.4 Interventions/Services

46 studies reported specific kinds of SP interventions for carers of PLWD or were delivered via the carer to help support both the PLWD and the carer of the person living with dementia [4, 5, 7, 8, 11, 23, 25, 26, 29-64, 66, 67]. These were predominantly umbrella interventions, which comprise a range of activities and services, including: cognitive interventions to support carers to support PLWD, such as memory clinics and reminiscence [35, 41, 63, 64]; case management interventions, including PDS, signposting, dementia advisor services, financial welfare, advice and advocacy, Admiral Nurses, and clinical advice and information [5, 11, 30, 33, 34, 48, 50, 53, 57, 62]; psychosocial interventions like dementia cafes, support groups, community engagement group, befriending and peer support networks [4, 5, 7, 11, 23, 25, 29, 30, 32-36, 38, 39, 41, 43, 45, 47, 50, 52, 54-56, 58, 59, 67]; physical well-being interventions, such as exercise classes and leisure centre access [40]; counselling interventions, including carer counselling, relational counselling and family counselling [8, 42, 44]; arts-based and creative interventions, including art, gardening and cooking [26, 41, 46]; occupational therapy interventions [31, 37, 60]; and digital interventions, such as a digital support platform [49].

Within these umbrella interventions, activities varied considerably, as did the intervention components (e.g., individualised support or group sessions), frequency or duration of the sessions, and mode of delivery (in person, online, telephone or email), therefore, highlighting the variability of SP interventions and services for carers of PLWD.

3.5 Mechanisms and Processes

Across the studies, the connector role manifested at different points in the SP process. In 38 studies, the referrer instigated the SP process and referred the carer of the person living with dementia to a connector that was part of a separate organisation from the referrer [4, 5, 7, 8, 11, 22, 25, 26, 28-31, 33, 34, 36-40, 42, 45, 47-49, 54-64, 66-68]. However, in 6 studies, the referrer embodied the connector role [23, 35, 44, 46, 51, 65], and directly signposted, through the use of a personalised care plan, carers of PLWD to SP interventions, and in 8 studies the connector was reported as the sole instigator (no referrer) of the SP process for carers of PLWD [24, 27, 32, 41, 43, 50, 52, 53].

In 44 studies, the SP process began and was instigated by a referral [4, 5, 7, 8, 11, 22, 23, 25, 26, 28-31, 33-40, 42, 44-49, 51, 54-68]. These included: referrals from primary care settings such as GPs, Admiral Nurses, dementia navigators, mental health nurses, clinical psychologists, occupational therapists and old-age psychiatrists [4, 5, 7, 11, 22, 25, 26, 33-37, 40, 42, 44, 45, 47, 49, 51, 55, 56, 59, 61-63, 65]; secondary care services such as clinicians from memory services, memory clinics and community mental health services [5, 7, 8, 11, 23, 26, 28, 31, 33, 37-40, 44, 46, 49, 51, 54, 56, 59, 60, 64, 66]; and charities and voluntary sector organisations including Alzheimer's Society, Age UK and Alzheimer's Scotland [5, 7, 8, 26, 29, 30, 33, 35, 36, 38, 39, 44, 46, 49, 51, 54, 56, 59, 60, 64, 66]. The SP process was also instigated by self-referrals [7, 33, 35, 49, 51, 56-60, 62, 64] or family referrals [7, 47, 51, 57], highlighting the diverse number of stakeholders and networks spanning the healthcare system involved in instigating the SP process.

Studies reported a diverse range of individuals acting as connectors for carers of PLWD; however, inconsistency of the terms used to describe connectors was evident across all included studies, and in some cases, it was difficult to establish whether the connector was addressing the needs of the carer or the person living with dementia. Examples of individuals who were acting as connectors in studies reporting carer of PLWD data included: clinical staff such as clinical dementia leads, Admiral Nurses, link workers and well-being practitioners [4, 5, 8, 23, 26, 30, 33, 34, 39-41, 43-46, 50, 51, 53, 57, 61, 65-67]; staff from memory clinics and mental health teams [22, 25, 55, 61, 63]; multidisciplinary teams comprising of staff from different specialties such as occupational health or psychology [24, 27, 31, 36-38, 41, 47, 51, 61]; and personnel from the third sector or voluntary and community-based organisations and enterprises, including befrienders, peer supporters and dementia advisors [7, 11, 28, 29, 32, 35, 42, 44, 46, 48, 49, 51, 52, 54, 57, 58, 61, 62, 68]. It is important to note that research teams, particularly in studies that assessed the effectiveness of SP, played a significant role in facilitating these connections post-referral [56, 59, 60, 64]. Furthermore, terms relating to connectors were used interchangeably across sectors, and in some cases, roles and the connectors' place in the SP process were not explicit.

Thirty-two studies reported the mechanisms of delivery in SP interventions and services for PLWD carers [4, 7, 23, 24, 26, 29-31, 33, 34, 36, 37, 40, 42-44, 47-56, 58, 60-64]. These diverse mechanisms comprised clinical staff and specialised therapists [4, 24, 31, 37, 44, 47, 48, 55, 56, 60, 63, 64] and non-clinical staff and staff from voluntary and community sector enterprises and charities [7, 23, 26, 29, 30, 33, 34, 36, 40, 42, 43, 49-54, 58, 61, 62]. And finally, 37 studies reported the mechanism of the overarching organisation(s) that provided or commissioned the SP services or interventions for PLWD carers [4, 5, 11, 24, 26, 29-38, 40-44, 47-57, 60-64, 67]. These included: voluntary and community sector enterprises and charities, such as Age UK, Alzheimer Scotland and faith-based organisations [4, 5, 11, 24, 29, 30, 32-38, 40, 41, 43, 44, 47, 51-54, 61, 67]; public sector organisations, such as NHS services and local authorities [11, 26, 31, 33, 34, 37, 38, 40-42, 47, 50, 53, 55, 56, 60, 61, 63, 64]; integrated services, which featured collaborations between healthcare service, charities, local government, community service and/or academic institutions [48, 49, 57, 62].

3.6 Reasons/Circumstances

Of the 52 included studies, 32 reported reasons for (motivations) and/or against (barriers) participating in SP interventions for carers of PLWD [4, 7, 8, 11, 23-26, 29-48, 55, 57, 58, 66] (see Table 2). The primary reasons for participating in SP interventions included seeking emotional support, such as peer support, creation of a supportive space and emotional gains [11, 23, 26, 29, 33, 34, 36, 43, 45, 55]; practical support, including signposting, financial advice, insight into dementia and action planning [4, 30, 31, 33, 37, 41, 42, 48, 55, 57, 58, 66]; social and community engagement, such as socialisation, educating the community, engaging in meaningful activities and time away from caring [8, 23, 29, 33, 35, 36, 40, 43, 55]; increasing knowledge and/or empowerment, including increasing confidence, self-esteem and dementia knowledge [7, 29-31, 34, 38, 42, 45, 55]; and coping strategies [37, 44, 45].

Significant barriers preventing carers of PLWD from participating in SP interventions included: a lack of cultural sensitivity, where services were not tailored to specific socio-cultural needs [11, 25]; practical barriers, in particular a lack of transport options to SP services, financial costs linked to attendance, lack of local SP resources and inability to access a link worker [7, 11, 30-33, 35, 36, 38-41, 45, 48]; health and physical barriers, including physical impairments and carer ill health [36, 38, 41, 45]; psychosocial and emotional issues, such as feeling like a burden to the health system, anxiety about attending group settings and seeing others further along in the dementia journey, and SP not considering the carer's emotional or psychosocial needs [4, 11, 29, 35-37, 42-45, 48]; and finally, information and/or communication issues, such as inconsistent communication between services, a disjointed referral, a lack of information about SP, SP information too overwhelming, and poor matching of services to carer needs [24, 31, 35, 38, 39, 42, 46, 48, 58]. These themes emphasise the need for more accessible, culturally sensitive, informed and co-ordinated approaches to SP support for carers of PLWD.

3.7 Outcomes

Positive and negative outcomes from carers of PLWD participating in SP interventions were identified in 44 studies [5, 7, 8, 11, 23-27, 29-49, 51-58, 60-64, 68] (see Table 3).

For carers of PLWD, the outcomes from SP interventions demonstrate numerous benefits. These include: enhanced independence, indicated by a reduced caring load and respite from caregiving duties, coupled with empowerment through knowledge [7, 24, 29, 31, 34, 39, 43, 45, 46, 48, 51, 52, 55, 58, 62, 68]; improved mood and well-being, including reduced stress and anxiety and improved emotional responses [11, 24, 31, 33, 37, 38, 40, 44-47, 51, 55, 58, 62, 63]; increased social connectedness, such as socialisation, peer support and a sense of belonging [5, 26, 29, 33-36, 39, 40, 42, 43, 45, 55]; mental and cognitive benefits, including better understanding of dementia, improved coping skills and normalisation of the dementia experience [11, 42, 44, 46, 55, 56, 63]; empowerment and identity, where carers retain their sense of purpose and feel valued [7, 11, 29, 30, 34, 43, 44, 46]; practical support and resources, highlighting better decision-making, assistance with financial and legal matters, and support from health services [7, 11, 25, 27, 30, 33, 41, 44, 46, 49, 51, 53-57, 62]; quality of life improvements, including enhanced well-being, resilience and confidence in caregiving capabilities [5, 23, 30, 33, 57]; positive PLWD–carer relationships, such as improved interactions with PLWD and reduced conflict [5, 8, 11, 24, 26, 30, 42, 52, 53, 55, 56, 58]; acceptance and adjustment, suggesting better coping strategies and facilitated acceptance of the dementia diagnosis [34, 37, 41, 43, 44, 55]; and finally, increased security and comfort, indicated by a sense of relief and reduced burden through continuous support [5, 27, 30, 51].

The negative outcomes included intervention suitability, where carers of PLWD felt poorly prepared because of a lack of information, or the intervention was not flexible to their support needs [11, 24, 27, 38, 61]; emotional impact, where carers experienced increased anxiety, stress from seeing others further along in the dementia journey, and the management of PLWD aggression towards carers not being adequately explored [38, 43, 49, 55, 63, 64]; service issues, such as unclear service scope, confusion about who the SP point of contact was, and negative experiences regarding staff communication during appointments [11, 24, 27, 38, 63]; activity relevance, such as limited activities matching interests and logistical difficulties with peer support systems [63]; affected PLWD–carer social dynamics, whereby the dependency on the relationship with PLWD and pre-existing family dynamics becomes strained [29, 31, 42]; and logistical challenges, where the onus on carers to locate and facilitate support, sometimes leading to employment sacrifices and long travel distances was highlighted [39, 56, 63].

Seven studies reported how outcome measures for carers of PLWD were assessed [32-34, 40, 47, 60, 64], which indicated varying assessments across several domains. These domains included: mental and psychological well-being, assessed by the Short Warwick–Edinburgh Mental Well-being Scale (SWEMWBS) [40]; mood-related outcomes, such as depression and anxiety, measured by the General Health Questionnaire 28 item (GHQ-28), the Positive and Negative Affect Schedule (PANAS), the Caregiver Strain Index (CSI) and the Hospital Anxiety and Depression Scale (HADS) [32, 47, 60, 64]; quality of life evaluated with instruments such as the EuroQol-5 dimensions (EQ-5D-5L), the Dementia Quality of Life Proxy Instrument (DEMQoL-Proxy) and the Adult Social Care Outcomes Toolkit (ASCOT) [32-34, 64]; daily activities, assessed with the Bristol Activities of Daily Living Scale (BADLS) [60]; self-management, including a sense of competence, assessed by the Sense of Competence Questionnaire (SCQ) [60]; and finally, the quality of the caregiving relationship measured using the Quality of the Caregiving Relationship (QCPR) [64].

4.1 Summary of Main Findings

The literature on SP for carers of PLWD in the United Kingdom is varied. Studies mainly focus on female carers of PLWD over 40, with various relationships between the person living with dementia and the carer. SP interventions vary in frequency and encompass activities that could be delivered exclusively for the carer or via the carer to the PLWD; some studies were unclear on this, making reporting results difficult. Services are often provided collaboratively by the NHS, charities and integrated services, with referrals from diverse sources. Connectors, including clinical, multidisciplinary and non-clinical staff from community organisations, link carers of PLWD to these interventions. However, the terminology regarding the connectors' roles and remit differs and establishing whether referrals are primarily for the person living with dementia or the carer of PLWD is difficult. Carers of PLWD participate in SP for emotional and practical support, coping strategies, social engagement, dementia education and empowerment. Barriers to participation include cultural insensitivity, practical issues, health problems, psychosocial concerns and communication challenges. Positive outcomes included improved carer mood, social connections, practical support, quality of life and better PLWD–carer relationships. However, intervention suitability, emotional impact, relevance and strained PLWD–carer relationships were associated with negative outcomes. Overall, SP for carers of PLWD hints at favourable outcomes, but its implementation is patchy, with co-ordination within the pathway lacking a uniform SP model for carers of PLWD that clearly separates their needs from the person living with dementia and addresses the logistical challenges of attending SP interventions.

4.2 Comparison With Existing Literature

This review reaffirms the inconsistent nature of SP in terms of scope, stakeholders and procedures reported in other literature in this domain [14, 70, 71]. Results in both Part 1 (PLWD) [12] and Part 2 (carers of PLWD) of this two-part series largely concur that SP is a promising intervention within dementia care but this paper (Part 2) sheds further light on the PLWD–carer relationship and the current SP pathway's lack of consideration that PLWD and carers' holistic needs are likely to be different to one another, or even at odds. Carers of PLWD identified support as a key benefit and reason for participating in SP, but the support was often generalised rather than tailored to specific carer needs. A qualitative study on culturally relevant SP for Pakistani carers also found carer-specific SP programmes lacked personalisation to the carer's holistic needs and did not consider wider cultural factors or how carers often go unnoticed and slip through the SP net due to a lack of carer self-identification [72]. This review highlights similar challenges for carers of PLWD.

The findings reflect the complexity of how and when carers of PLWD seek help, demonstrated in this review by a variety of referral routes and stakeholders within the pathway. This complexity is potentially exacerbated by the ‘hidden’ nature of caregiving and the broader social, cultural and economic influences on individuals' health [73, 74]. However, integrating such complexity within an SP model is challenging, suggesting the need for a structured model for carers of PLWD that encompasses clearly defined core components that are flexible to the inevitable contextual variables that are innate to caregiving.

4.3 Strengths and Limitations

This systematic review showcases a variety of innovative approaches offering valuable insights for policymakers and practitioners. However, it is limited by the included studies' heterogeneity, making comparison of outcomes challenging and conclusions difficult to draw. Furthermore, evidence of effectiveness was difficult to determine due to gaps in the literature, findings were difficult to generalise due to data heterogeneity, and potential biases in study selection and publication necessitate cautious interpretation, thus highlighting the need for further primary research. Another limitation of this review is that, due to its explicit focus on SP interventions for carers of PLWD, it does not include evidence on interventions aimed specifically at PLWD–carer dyads. Although initially intended to explore the dyadic approach, the complexity and extensive nature of the available evidence necessitated splitting the review into separate manuscripts targeting carers and PLWD individually. As a consequence, valuable insights concerning the feasibility, challenges and implementation complexities associated with dyadic interventions have not been captured here and merit exploration in dedicated future research.

4.4 Implications for Policy and Practice

This review identifies components of SP interventions that could be integrated into national dementia care and carer-related strategy and policy. It provides guidance on resource allocation and demonstrates the positive and negative health outcomes associated with SP for carers of PLWD. The evidence from this review supports policies that encourage person-centred, holistic approaches and greater collaboration between SP stakeholders to ensure coordinated, timely and carer-focused support.

This review provides insights into ways to improve SP service delivery by identifying reasons carers of PLWD do and do not participate in SP intervention, which can help clinical and community practitioners design tailored SP interventions in the hope of improving SP uptake and effectiveness for carers of PLWD.