Person‐centred integrated care for people living with Parkinson's, Huntington's and Multiple Sclerosis: A systematic review

Abstract Introduction People living with long‐term neurological conditions (LTNCs) have complex needs that demand intensive care coordination between sectors. This review aimed to establish if integrated care improves outcomes for people, and what characterises successful interventions. Methods A systematic review of the literature was undertaken evaluating multisectoral integrated care interventions in people living with Parkinson's disease (PD), Multiple Sclerosis (MS) and Huntington's disease (HD). Strength of evidence was rated for the different outcomes. Results A total of 15 articles were included, reporting on 2095 patients and caregivers, finding that integrated care can improve people's access to resources and reduce patients' depression. UK studies indicated improvements in patients' quality of life, although the international literature was inconclusive. Few programmes considered caregivers' outcomes, reporting no difference or even worsening in depression, burden and quality of life. Overall, the evidence showed a mismatch between people's needs and outcomes measured, with significant outcomes (e.g., self‐management, continuity of care, care experience) lacking. Successful programmes were characterised by expert knowledge, multisectoral care coordination, care continuity and a person‐centred approach. Conclusions The impact of integrated care programmes on people living with LTNCs is limited and inconclusive. For a more person‐centred approach, future studies need to assess integrated care from a service‐user perspective. Patient and Public Contribution Thirty people living with LTNCs were involved in this review, through defining research questions, validating the importance of the project, and increasing the researchers' understanding on what matters to service users. A patient and public involvement subgroup of representatives with lived experience on PD, MS and HD identified the need for more person‐centred integrated care, with specific concerns over care fragmentation, care duplication and care continuity. This was key to data analysis and formulating the characteristics of successful and unsuccessful integrated care programmes from the perspective of service users. The discrepancy between service users' needs and the outcomes assessed in the literature point to user‐driven research as the solution to address what matters to patients and caregivers.

project, and increasing the researchers' understanding on what matters to service users.A patient and public involvement subgroup of representatives with lived experience on PD, MS and HD identified the need for more person-centred integrated care, with specific concerns over care fragmentation, care duplication and care continuity.This was key to data analysis and formulating the characteristics of successful and unsuccessful integrated care programmes from the perspective of service users.The discrepancy between service users' needs and the outcomes assessed in the literature point to user-driven research as the solution to address what matters to patients and caregivers.

K E Y W O R D S
Huntington's disease, integrated care, Multiple Sclerosis, multisectoral, Parkinson's disease, person-centred outcomes

| INTRODUCTION
6][7][8] Both motor and non-motor features result in selfmanagement difficulty, increased dependence, and caregivers' burden.With more than 600 neurological conditions, 9 it is crucial to understand the commonalities across conditions for a better integrated service response.
Evidence shows that people living with Parkinson's disease (PD), Multiple Sclerosis (MS) and Huntington's disease (HD) have common unmet needs that negatively impact on their experiences of care and care outcomes: ,24,26,36 People living with rare neurological diseases, such as those impacted by HD, seem to face additional needs, as reported in the National Neurological Patient Experience Survey 2018/2019 37 from more than 10,000 people; this resulted in a follow-up report specifically looking at the needs of people living with rare neurological diseases 38 .Particularly looking at HD, their needs differ from PD and MS, due to its rare and hereditary nature, whose impact is stated in the literature as: isolation, 39 lack of professional and public awareness 31,36,39 ; limited resources (e.g., many long-term facilities not accepting HD patients) 29,31,36 ; and familial needs.35,39 Some of these extended needs were explored by a recent survey where, even within a rare disease scope, people with HD and other choreas experienced higher difficulties in accessing care.Reasons for this were the small number of experts who usually work at public and private institutions, expensive consultations, long waiting lists and lack of knowledge amongst clinicians. 40 These un needs demonstrate how fragmented care delivery undermines the capability to meet the complex care needs of people living with LTNCs.Policy suggests an integrated care response is needed. 41,42 The concepts evolved through time and taken several definitions.43,44 This review adopted the definition from the World Health Organization (WHO) 41,45 because it aligns with the multisectoral care required in LTNCs-integrated care is delivered by a coordinated multidisciplinary team of providers working across settings and levels of care, through intersectoral and multisectoral actions. A multisectoral approacs understood as the collaboration between various stakeholder groups from: "macro (society structures at national or governmental levels), meso (middle groups of organizations like communities, voluntary sector or neighbourhoods) and micro (local individual level e.g., personal networks) societal levels of action" 46 (p.8) to achieve policy, health and practice related outcomes.
Integrated care has shown improvements in other long-term conditions like cancer, diabetes and cardiovascular diseases, [47][48][49][50][51] increasing patient satisfaction, perceived quality of care, and access to care.Little is known though about its impact on people living with LTNCs.A 2010 rapid review 52 pointed out that despite the growth in models of care being tested for people with LTNCs, the evidence base about the best models to adopt remained underdeveloped.The review highlighted that multidisciplinary work alongside clinical nurse specialists could improve care continuity, but patient-focused outcomes were largely absent from the studies included.Indeed, the authors reported that fewer than half of the studies undertook any assessment from service users' perspective.With little comparative information available, the authors questioned if users' feedback reflected their gratitude for receiving any service, or rather if the model being tested was better than the standard of care.
The current review expands on the work by Parker et al. 52 by taking a multisectoral approach to integrated care, a more developed and up-to-date concept than continuity of care by Freeman et al. 53 ; second, it will specify a rare neurological condition (HD) aiming to build knowledge across prevalent and rare neurological conditions, for better services response; third, it will provide an update on the last two decades since Parker's search was conducted in 2006; lastly, it will employ a systematic and rigorous search with a service-user perspective lenses to meet the gap on person-centred outcomes.
To date, no systematic literature review has gathered knowledge across prevalent and rare LTNCs to understand the effect of integrated care programmes on this population.Therefore, this review aims to identify the key characteristics of successful integrated care programmes tested in people living with PD, MS and HD and their outcomes on patients and caregivers.

| Search strategy and selection criteria
The research team conducted a systematic review of the international evidence, examining the characteristics and impact of integrated care programmes in people living with PD, MS and HD.
The protocol was registered on PROSPERO (number CRD42022 314740). 54The review is reported in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines 55 (Supporting Information S1: Appendix 1).Outcome measures were graded for strength, to report where there was greater or lesser strength (or certainty) in the evidence.
| 3 of 16 This approach infers certainty based on two factors: the methodological quality of the individual studies and the plausibility of each study finding. 66It is important that any assessment of the strength of evidence considers the quality and volume of studies, but also considers consistency. 67This evaluation draws on work by Hoogendoorn, 67 with principles from the GRADE and CERQUAL rating schemes, 66,68 and work from Baxter. 51,69To evaluate the strength of the evidence comparator labels were used.The rating scale was as follows: 'stronger evidence' represented generally consistent findings (more than half) in multiple studies with a comparator group design; 'weaker evidence' represented generally consistent findings in one study with a comparator group design and several noncomparator studies, or multiple noncomparator studies; 'very limited evidence' represented an outcome reported by a single study; and finally, 'inconsistent evidence' represented an outcome where fewer than 75% of studies agreed on the direction of effect.
United Kingdom and international evidence with comparator and noncomparator studies were separately rated, and then an overall rating effect across study type was provided.Each outcome reported was recorded either by a plus '+' meaning that the study reported an improvement for this outcome, by an equal sign '=' meaning no significant change, or by a minus sign '−' meaning a decline for this outcome.Following rating in individual studies, overall ratings were achieved across all evidence, grouping these in relation to patients, caregivers and resource use/system impact.Strength of evidence appraisal was undertaken by the research team (S.B. P., M. C. and D. K.) at a series of meetings to establish consensus.
The quality of the included studies was independently appraised by two authors (S.B. P., D. K.) applying the Critical Appraisal Skills Programme. 70For studies with comparative designs, the authors considered sources of potential bias based on the Cochrane Handbook. 71Disagreements were resolved by discussion and consensus with a third author (M.C. P.).

| Patient and public involvement (PPI)
This systematic review was conducted with a PPI group composed of

| RESULTS
Database search identified 20,765 articles (Figure 1), following deduplication this yielded 11,861 papers.A total of 11,617 articles were excluded on title and abstract screening.One reference could Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow-chart for study selection.
not be retrieved despite contacting the author institution and the journal editor.A total of 243 full-text studies were screened and 229 excluded on full-text screening leaving 14 eligible studies.][74][75][76][77][78][79][80][81][82][83][84] 73 with less including house/safety/environment and financial needs. 76Some characteristics were harder to clarify due to limited reporting, like data access, transfer between providers and updating of data.For example, Connor et al. 73 mentioned a patient portal and a notebook, but it is unclear how/if other teams had access to the system, how each tool was used and how the care plan was updated.

| Studies outcomes
The review identified an extensive range of outcomes from the included literature summarised in Table 2 (Supporting Information S1: Appendix 6).Integrated care evidence was stronger for three outcomes: improved/decreased depression in patients, no impact in caregiver's burden and improved people's access to resources.UK studies indicated an improvement in patients' quality of life.

| Patient outcomes
Most studies focused on reporting patient outcomes, particularly clinical outcomes, related to disease progression and motor symptoms, 63,73,75,77,78,81,83,84 with varied scales and outcomes measured.Their impact presented inconclusive evidence, with a mixture of improvement, no significance and decline.Nonmotor symptoms, mental well-being, health related quality of life and quality of life were less reported, with inconsistent evidence.Nonmotor symptoms and health-related quality of life were assessed in international literature but not in UK studies.Depression was assessed in only one UK study, 78 showing improvement, which was supported by international evidence 73,84 showing strong evidence.
Quality of life was assessed in two UK studies 78,82 showing an improvement.Internationally there was inconsistent evidence and overall, it remained inconsistent.Other outcomes: education, information received, self-management/self-efficacy; unmet needs identified and needs met; collaboration between providers; continuity of care; and perceived care were found in only four international studies 63,73,80,84 and neither in United Kingdom.These studies presented inconsistent or very limited evidence.Needs being met 80 showed improvement for motor and personal care needs.Collaboration between providers 73 showed improvement, and continuity of care and perceived care showed both improvement and no significance. 63,73,80

| Caregiver outcomes
A few studies assessed caregivers' outcomes, reporting on depression, burden, and quality of life.Indeed 71% of the studies did not assess caregiver's outcomes.However, the few that did, 63,75,77,78,84 revealed high and increasing burden.Depression and quality of life was only reported by Trend et al. 78 and showed no difference.
Burden was the most assessed outcome for caregivers, as reported in four international studies.Three studies 63,77,84 showed no difference and one 75 showed that caregiver's burden worsened through the study.In Trend et al.'s 78 paper caregiver's burden was high with 10% of caregivers found in danger of being unable to continue caring.
Through the programme carer's strain remained unchanged.In Fleisher et al.'s 75 studycaregivers' strain increased mild to moderate after 1 year in the study, and some that withdrew were under severe strain.Munoz et al. 74 assessed caregiver's burden postintervention but without baseline data it was not possible to establish its impact.

| Resource use and system outcomes
Outcomes related to resources use/system impact were varied: frequency of appointments, access to resources and healthcare utilization.Most of the outcomes assessed showed very limited evidence, being reported by individual studies which did not allow for a comparison across the literature.Only one UK study 83 reported on this category, showing a reduction in length of stay in hospital; conversely one international study 79 showed no difference.Admissions to the hospital were assessed in three studies 76,79,85  difference and one 76 showing a reduction.The increase or decrease of appointments with different professionals could be seen as positive or negative depending on how care was perceived by people.However, most studies that reported on healthcare utilization did not report on patients' experience.Only one outcome showed strong evidence in this category: improved access to other resources, reported by two international studies. 73,803 | Integrated care programmes characteristics

| Facilitating factors
When exploring the characteristics of the integrated care programmes 73,78,80,82,84 that shown higher certainty (stronger and weaker strength) of improving people's outcomes, these had in common all four characteristics: 1. Specialist staff leading care.The teams were led by specialist staff in their disease-related areas, hosted at hospitals and specialist centres.

| Hindering factors
When exploring the characteristics of the integrated care programmes that did not show significant differences or show decline in people's outcomes, 77,81,83 it became evident that these studies focused on assessing clinical outcomes.For example, Oeseburg et al. 81 reported meeting the needs of 2/3 of the participants and a reduction in people's needs.However, the primary outcomes selected did not reflect the positive impact of the programme.The same occurred on Makepeace et al., 83 where despite clinical outcomes pointing to disease progression, data related to living with the disease did not report worsening, suggesting better living with MS.Patients highlighted improved accessibility to resources and continuity of care.Although Makepeace et al. 83 focused on motor/ functional assessments, it did report on psychological wellbeing, which was crucial to understand its positive impact.Without this, its impact would have been missed.Furthermore, these programmes had feasibility issues with coordination and continuity of care.For example, van der Marck et al. 77  In this systematic review, key characteristics of integrated care programmes that resulted in better outcomes for people living with PD, MS and HD included 1. Expert knowledge; 2. multisectoral care coordination; 3. care continuity and, 4. person-centred approach.This review also identified several obstacles to integration including issues with data access and transitions between providers and found that integrated care impact on service users remains understudied.

| Peoples' needs versus outcomes assessed
Our review shows that despite the complexity of interventions evaluated, the impact on people remains uncertain.The lack of research on the impact of integrated care on service users had been previously reported. 52Parker et al. 52 found that patient outcomes, related to personal choice, empowerment, or continuity of care were largely absent from studies.This is consistent with this review results; despite people living with PD, MS and HD reporting common needs asking for better person-centred integrated care, the most common outcomes assessed in the literature are clinical outcomes.We found strong evidence of reduction in patient's depression and improved access to resources, but other important outcomes matching people's care needs remained largely untested.Continuity of care was mostly untested despite its importance, but disease progression remained consistently tested despite the context of incurable neurodegeneration.Similarly, our review shows that caregivers' needs remain unmet despite being under severe distress. 75,78When carers views were considered 63,75,77,78,84 it was often unclear on how caregivers' needs were identified and addressed.This was not surprising considering that up to 85% of caregivers reported that their needs had not been assessed. 37Several studies 13,17,18,24,30,32

| Recommendations in developing new interventions
The In contrast, expert staff, good coordination between multisectoral providers, continuity of care and person-centred approach are essential pillars that result in improved outcomes.These suggestions are consistent with previous literature,  90 To advance integrated care for patient benefit, userdriven outcomes that reflect person-centred care are a potential solution 91,92 ; this will require involving patients and caregivers throughout the design stages to ensure relevance to users, [93][94][95] instead of systems/organisations. 96While new measures of people's experiences of care are being developed, 97 there is much more to be done to effectively understand the challenges that patients and caregivers face in negotiating the maze of services, organisations and funding and use this knowledge to deliver better care. 98Indeed, this strikes an important chord highlighting that successful integrated care interventions require multisectoral change (e.g., increase access to respite care) while focussing on person-centred long-term outcomes to capture their impact at user-level (e.g., burden).

| Strengths and limitations
The strengths of this review include an analysis of evidence strength from the perspective of patients' and caregivers' outcomes.Moreover, considers knowledge across three LTNCs, guided by patient and public contributors, adding value to the research conducted.
However, one could argue that this focussed search on integrated care programmes for people living with PD, MS and HD as exemplar conditions, could be considered a limitation as it potentially excluded other noteworthy programmes or conditions.Considering there are hundreds of LTNCs it is acknowledged that this review represents a fraction on this field.
Our database search was conducted in 2021, meaning more recent papers may have been missed.To reflect on this limitation we used Cochrane's 99 guiding checklist of when and how to update systematic reviews, considering that systematic reviews are time and resource consuming.We rerun our search strategy in MEDLINE and Google Scholar on the 9 October 2023 and did not find any papers published in this 2-year period that would change our findings and conclusions.We did identify promising studies 100,101 currently being conducted in PD that, depending on their results, may prompt the need to update this systematic review in the future.
Our data extraction was primarily led by one author (S.B. P.), this may have introduced some level of researcher bias.Steps were taken to reduce this bias by independently testing the data extraction tool and several discussions took place amongst the researchers (S.B. P.,

2 . 3 . 4 .
Person-centred care.The interventions focused on participants' specific needs and towards developing a personalised care plan.Coordination of care.These interventions involved a care coordinator responsible for delivering the care plan and followups.The role was mostly performed by nurses, but some studies had a social care worker or used a dedicated specialist team to navigate care.Continuity of care.All these interventions were characterised by planned reviews and follow-ups.
findings from this review can support the development of future integrated care interventions.We found that operational aspects like data centralization and transfer of data between professionals were overlooked and require attention in the development of future interventions at the risk of contributing to fragmentation.Lack of data sharing is a known barrier to integration and people cannot move between services and sectors seamlessly, 44 a universally recognised problem across any country or condition.Hindering factors should be addressed to increase the success of future interventions.
30 adults living with a LTNC, either diagnosed, at risk (HD) or caring for someone impacted by a LTNC.Some PPI meetings were designed to meet with people with different disease experiences and discuss overlapping concerns.Other PPI meetings were funnelled to work specifically with people living with PD, HD and MS and subgroups met separately to voice disease-related concerns.Meetings were conducted remotely and addressed different agendas: defining research questions, discussing the value of the project, refining data extraction templates, interpreting results and deciding on recommendations for successful integrated care interventions.

Table 1
65,73,74The Netherlands, United Kingdom, and Colombia.Across the articles, a total of 11 interventions were identified for PD, 10 studies were identified, exploring seven interventions; for MS, five studies were identified, exploring four interventions; for HD, no studies were identified.Their length varied between 8 weeks and 29 months, with complex multilevel/multisectoral components, summarised in Figure2.The most prevalent sector was public health represented by secondary care, often associated but not always with primary care.The least represented sector was private care, identified in only two interventions.65,73,74Manystudies reported having a care coordinator or specialist staff delivering care.Ten of the interventions also assessed personcentred care needs, although the extent of the assessments varied between studies-interventions focused on patients' medical and psychosocial assessments, Characteristics of included studies.
but showed inconsistent evidence, with two studies showing no T A B L E 1 Public sector: local government, the civil service, the NHS and higher education.Levels of health care: Primary care-GP, dentists and pharmacists.Secondary care-Community and hospital care.Planned care or urgent and emergency care.Tertiary care-Highly specialised treatment, for example, neurosurgery.Private sector: private and independent companies, organisations and consultancy firms.Third sector/voluntary care sector: Voluntary, community and social enterprise (charities).
81cked continuity of care by failing to schedule follow-ups or to have a care coordinator to review/action the care plan as needed.Similarly, Oeseburg et al.81faced obstacles on data transfer between providers.T A B L E 1 (Continued) a Sectors/levels of care.Abbreviations: HD, Huntington's disease; M, months; MS, multiple sclerosis; n, number; PD, Parkinson's disease; RCT, randomized controlled trial; W, weeks a Sectors/levels of care.
Characteristics of models of integrated care in the included literature.Outcomes' strength of in UK and non-UK included studies.
a Newcastle independence scale showed no difference while Expanded Disability Status Scale and Functional independence measure showed decline.b Hoehn and Yahr not statistically significant, while Unified Parkinson Disease Rating Scale total score was statistically significant.c Physician examination.d Assessment of motor complications (i.e., on/off) for management, identification of motor complications.
75e findings suggest a discrepancy between people's needs and what programmes currently offer and the outcomes that are being assessed, questioning if current guidelines and integrated care policy are fit for purpose.Despite recommendations of integrated care to manage patients' complex needs, what success looks like still remains unclear.Studies that evaluated integrated care measured and reported varied outcomes (from Newcastle Independence Scale, to Expanded Disability Status Scale and Functional Independence Measure83to Hoehn and Yahr and Unified Parkinson Disease Rating Scale75), making it difficult to compare results.This shows a need for further discussions around the core outcomes that matter most to people to explore if integrated care programmes actually benefit the intended end users.Methodological consensus regarding what aspects of integrated care should be measured would allow future researchers and clinicians to make sense of all the knowledge produced and thus improve the rate of progress in developing interventions.The WHO also recently acknowledged the need to develop a core set of indicators and targets to monitor national multisectoral action plans for intersectoral global action on neurological disorders.