Organizational interventions improving access to community-based primary health care for vulnerable populations: a scoping review

Abstract

Access to community-based primary health care (hereafter, ‘primary care’) is a priority in many countries. Health care systems have emphasized policies that help the community ‘get the right service in the right place at the right time’. However, little is known about organizational interventions in primary care that are aimed to improve access for populations in situations of vulnerability (e.g., socioeconomically disadvantaged) and how successful they are. The purpose of this scoping review was to map the existing evidence on organizational interventions that improve access to primary care services for vulnerable populations. Scoping review followed an iterative process. Eligibility criteria: organizational interventions in Organisation for Economic Cooperation and Development (OECD) countries; aiming to improve access to primary care for vulnerable populations; all study designs; published from 2000 in English or French; reporting at least one outcome (avoidable hospitalization, emergency department admission, or unmet health care needs). Sources: Main bibliographic databases (Medline, Embase, CINAHL) and team members’ personal files. Study selection: One researcher selected relevant abstracts and full text papers. Theory-driven synthesis: The researcher classified included studies using (i) the ‘Patient Centered Access to Healthcare’ conceptual framework (dimensions and outcomes of access to primary care), and (ii) the classification of interventions of the Cochrane Effective Practice and Organization of Care. Using pattern analysis, interventions were mapped in accordance with the presence/absence of ‘dimension-outcome’ patterns. Out of 8,694 records (title/abstract), 39 studies with varying designs were included. The analysis revealed the following pattern. Results of 10 studies on interventions classified as ‘Formal integration of services’ suggested that these interventions were associated with three dimensions of access (approachability, availability and affordability) and reduction of hospitalizations (four/four studies), emergency department admissions (six/six studies), and unmet healthcare needs (five/six studies). These 10 studies included seven non-randomized studies, one randomized controlled trial, one quantitative descriptive study, and one mixed methods study. Our results suggest the limited breadth of research in this area, and that it will be feasible to conduct a full systematic review of studies on the effectiveness of the formal integration of services to improve access to primary care services for vulnerable populations.

Introduction

Health systems are struggling to provide equitable access to community-based primary health care (hereafter, ‘primary care’) services [1, 2]. The access to primary care services is worse for populations in situations of vulnerability (hereafter, ‘vulnerable populations’) such as poor, immigrant, and aboriginal citizens in Canada and Australia [3–6]. Emerging evidence from Canada and Australia shows that various reforms are aiming at improving access to care, but may not be well adapted to vulnerable populations [7, 8].

These access problems can pertain to the way care is offered as well as to the actual ability of people to seek, reach and engage with the care [9]. Organizational interventions might target both adjustments to the way care is delivered as well as targeting the development of people’s capacity to obtain care [9]. While access-related problems for vulnerable populations have been documented, few reviews have looked at the evidence regarding how successful programs have been at addressing access issues for these populations [10].

Knowledge remains scant about the actual scope of interventions that go beyond the establishment of specific programs aimed at improving the usual way primary care is delivered for vulnerable populations. Therefore, the purpose of this scoping review was to describe the nature and breadth of published research studies in peer reviewed academic journals on organizational interventions improving access to primary care services for vulnerable populations, and reducing consequences of poor access in these populations.

Review

Methods

As part of the Australian-Canadian IMPACT program (Improving Models Promoting Access-to-Care Transformation), a scoping review was chosen to (i) map relevant studies regardless of the design, theoretical rationale, and discipline; and (ii) identify a candidate research focus for a subsequent systematic review [11, 12]. Scoping reviews are used to identify knowledge gaps, set research agendas, and identify implications for decision-making. Specifically, scoping reviews are aimed to explore the breadth of available evidence in a research domain (main available research studies), and map the concepts underpinning this domain, which can lead to plan and conduct a systematic literature review if enough evidence to answer a specific question [13, 14]. Scoping reviews typically include five iterative stages: definition of the research question, identification of the relevant studies, selection of the studies, charting of the data, collating, summarizing and reporting the results. We included studies with all types of design (comprehensive approach), followed an iterative process (e.g., adjustment of the search strategy), and involved experts (the last four co-authors) throughout.

Definition of the research questions

The specific research questions of the scoping review were as follows. What are the types of organizational interventions in primary care aiming at improving access for vulnerable populations? What are the documented impacts in terms of avoidable hospital admissions, emergency department presentations and unmet needs for care?

Identification of the relevant studies

This stage involved searching the following bibliographic databases: MEDLINE, Embase and CINAHL. The search strategy was designed by all co-authors, then validated and performed by a specialized librarian (example is presented in Appendix 1). The search was expanded using references in the selected studies and pertinent existing literature reviews (citation tracking). Given the scoping nature of our work, the grey literature was not searched.

Eligibility criteria were as follows: quantitative, or qualitative, or mixed methods study conducted in countries in the Organization for Economic Cooperation and Development (OECD); published in English or French between January 2000 and March 2014 (2000 was chosen as it corresponds to a shift, worldwide, towards community-based primary health care); about (i) vulnerable populations, i.e., socioeconomically disadvantaged (e.g., uninsured), racial and ethnic minorities (e.g., indigenous people), people with one or more chronic health condition (including mental illness), (ii) access-related interventions in primary care organizations, i.e., primary care setting, medical home, community health center (e.g., community mental health service), primary care services in other settings (e.g., school-based health care program), specialized care integrated in primary care settings (e.g., psychiatric team in a medical home), and (iii) evaluated impact on reduction of at least one of the following consequences of poor access: hospitalization, or emergency department admission, or unmet health care needs [9].

Selection of the studies

This stage consisted of an iterative process in which (contrary to a systematic review process) we searched the literature, refined our search strategy based on the new findings in the identified articles (e.g., if a new organizational intervention type has been identified we included it in searched words of database - MeSH to retrieve more studies), asked experts (JH, GR, GJ, J-FL) to share their personal files, and tracked citations in selected references and literature reviews. Using the eligibility criteria, relevant publications were selected by one researcher with extensive experience in systematic reviews (VK) [15–17] and in case of doubt discussed with another researcher (PP). The selection of records (title/abstract) was very sensitive, and the selection of full-text papers was specific. It was easy to exclude bibliographic records that were obviously not relevant. In case of doubt regarding a record, the corresponding full-text paper was automatically screened. Excluded full-text papers were obviously not relevant.

Charting the data

The following data were extracted from each included study: (i) author, year of publication, study country; (ii) study design (e.g., randomized controlled trial); (iii) study population (e.g., sample size); (iv) vulnerability context (e.g., elderly patients); (v) main characteristics of the intervention; (vi) other elements (e.g., cost); (vi) outcomes (hospitalization, emergency department admission and unmet health care needs).

Collating, summarizing, and reporting the results

We used a three-step qualitative synthesis: (Step 1) a classification of organizational interventions, (Step 2) a classification of access dimensions and outcomes of intervention, and (Step 3) a ‘dimension/outcome’ pattern analysis. Specifically, we conducted a theory-driven qualitative content analysis to classify interventions, dimensions and outcomes [18]. For each included study, we extracted key sentences eliciting the type of intervention, dimension and outcome (derived from previous classification and conceptual framework).

Step 1. Classification of organizational interventions

Interventions assessed in the included studies were categorized using the following financial and organizational types of intervention derived from the checklist of the Cochrane Effective Practice and Organization of Care Review Group (EPOC) [19]. The EPOC provides different categories (e.g., financial intervention) and subcategories of intervention. Based on the description of interventions in the included studies, the first author (VK) assigned them to the EPOC categories and sub-categories. Typically, this classification was straightforward. In case of doubt, the study was discussed with the second author (PP) and the final classification was based on consensus.

• 1. Continuity of care via case management: Coordination of assessment, treatment and arrangement for referrals.

• 2. Formal integration of services: Bringing together services across sectors or teams (all services at one time).

• 3. Clinical multidisciplinary team: Creation of a team with professionals from multiple disciplines (or new team members).

• 4. Continuity of care via arrangement for follow-up.

• 5. Revision of professional role: Shifting of roles among healthcare professionals, or expansion of role to include new tasks.

• 6. Institution incentive: Financial reward to the organization or providers for doing specific action.

• 7. Capitation: Set amount per patient.

Step 2. Classification of access dimensions and outcomes

Interventions assessed in the included studies were categorized using the ‘Patient Centered Access to Healthcare’ conceptual framework in terms of outcomes and dimensions [9]. First, the key outcomes were threefold: reduction of avoidable hospitalization, emergency department admission, and unmet health care needs (Fig. 1). These outcomes were chosen because they are commonly proposed in the literature and institutionalized in research funding and governmental agencies [20–23]. For example, numerous studies demonstrated that increasing access to primary care services is associated to an improvement of these three outcomes. As another example, these outcomes were chosen by the Canadian Institutes of Health Research as national priorities for primary care studies and research teams [24]. Second, the key dimensions of access were as follows.

Fig. 1

The ‘Patient Centered Access to Healthcare’ conceptual framework. Note: Conceptual framework adapted by the IMPACT program led by the last four co-authors (www.impactresearchprogram.com) from Levesque et al. [9]

• 1. Approachability: Existence of reachable services.

• 2. Availability: Getting services in time.

• 3. Affordability: Financial capacity necessary to use services.

• 4. Acceptability: Cultural and social acceptance of services.

• 5. Appropriateness: Fit between services needed and obtained.

Step 3. ‘Dimension/outcome’ pattern analysis

Patterns were suggested when groups of studies on similar interventions were associated with similar access dimensions and similar outcomes (positive versus no effect). Within groups, each study had the same weight regardless of their design. We looked for ‘dimensions of access to primary care services and outcomes’ patterns (dimension-outcome patterns). We grouped studies that shared a given type of outcome (e.g., emergency department admission) and we searched for their shared conditions (presence/absence of each access dimension). Outcomes were categorized and coded as “positive” (reduction of avoidable hospitalization, emergency department admission, and unmet health care needs) or “no effect” (no reduction). For each group, a pattern is suggested when all studies (or almost all) had similar outcomes and access dimensions (vote counting). This pattern analysis was conducted without and with consideration of the vulnerable population type (e.g., elderly patients versus uninsured persons).

Results

Search results

The search results are outlined in a flow chart (Fig. 2). Out of 8,694 records, 6,943 were not eligible based on the title and/or the abstract, and 1,721 were excluded based on the full-text publications. An additional nine eligible studies were identified through citation tracking and personal files of researchers, leading to include 39 studies in total (Fig. 2).

Fig. 2

Flow Chart

Description of included studies

Twenty-six studies were conducted in the USA [25–51], six in Canada [52–57], three in the UK [58–60], two in New Zealand [34, 61], one in Australia [62] and one in Italy [63] (Table 1). Thirty-six were quantitative studies including 11 randomized controlled trials [35–43, 49, 51, 55, 62], 22 non-randomized studies [25, 27–34, 44–48, 51, 53, 54, 58–60, 63, 64], three quantitative descriptive studies [26, 52, 61], and three mixed methods studies (Table 1) [34, 50, 56]. Twenty-five studies (64.1 %) concerned patients with chronic conditions, and 14 examined (35.9 %) socioeconomically disadvantaged populations (Table 2).

Table 1 Description of included studies

Table 2 Vulnerability context

Thirty-five studies (89.7 %) concerned organizational interventions, including revision of professional roles [61, 62], clinical multidisciplinary teams [44, 45, 50, 52, 54], formal integration of services [26, 29, 31, 33, 34, 41, 46, 53, 56, 64, 65], and continuity of care via case management [27, 30, 32, 35–40, 43, 47, 49, 51, 55, 60, 63] or arrangements for follow-up [48, 57]. Four studies (10.3 %) concerned financial interventions, namely institution incentives [28, 58, 66] and capitation [25].

Description of the organizational interventions

Continuity of care via case management

This organizational intervention is designed to coordinate different medical and social services via a case manager (i.e., a nurse) who closely works with PCP [27, 30, 32, 35–40, 43, 47, 49, 51, 55, 60, 63]. A case manager is responsible for assessment of care needs, development of care plan in collaboration with other health care professionals, regular follow-up and liaison of services. In the identified studies majority of participants were elderly patients with multiple chronic conditions and functional disabilities [35, 38, 39, 49, 51, 55, 59, 60, 63]. Other categories of the patients were uninsured [30, 40, 47] and formerly incarcerated people [37, 43], children with special health care needs [27, 32], and patients with psychiatric disorders [36].

Formal integration of services

This organizational intervention targets to bring all services (medical and social) at one point [44, 45, 50, 52, 54]. Four types of intervention strategies have been used in the identified studies. The first strategy was to bring together primary care and secondary/tertiary services, i.e., integrate specialists into primary care settings such as mental health teams [29, 41, 42, 65], community service teams [26], and alcohol-substance abuse counselors [31]. The second strategy was for brokers or community health workers to identify proactively eligible patients (e.g., in the emergency room) and assign them to a primary care practitioner [31, 33, 34, 46]. Third, a network was developed and integrated services using a ‘single entry point’ (integration of home care, rehabilitation and hospital services) with 24/7 telephone access [53, 64]. Fourth, informatics-based integration allowed virtual monitoring of complex health conditions from primary care to hospital-based services (telehomecare) [56]. The main categories of vulnerable populations targeted by this intervention were patients with low income or uninsured [26, 31, 33, 34, 46], patients with mental health problems [29, 41, 65], and elderly patients with multiple chronic conditions [53, 56].

Clinical multidisciplinary team

This organizational intervention is based on two approaches - creation of a team with healthcare professionals from multiple disciplines [45, 50] or addition of a new member to the existing team (i.e., local indigenous health workers [62] or ethnic group representative [44], a dietitian [52], a nurse practitioner in a team of mental health professionals [54]).

Continuity of care via arrangement for follow-up

This organizational intervention is based on close follow-up either post discharge [57] or on a predefined frequency [48] to ensure timely access to services.

Revision of professional role

A new role has been assigned to provide a different care in one study (a social worker of local ethnicity trained in skin infection recognition) [61].

Institution incentive and capitation

These organizational interventions are based on financial incentives to provide a financial reward for performing specific action [28, 58, 66] or to award a certain amount per patient seen [25, 67].

Pattern ‘dimension-outcome’

Regarding access dimensions and outcomes, the characteristics of studies on local/regional interventions and state/national interventions are described in Appendix 2 and 3, respectively. The dimension-outcome patterns are summarized in Table 3. The pattern analysis revealed one pattern. Results of the 10 studies on interventions classified as ‘Formal integration of services’ showed that in almost all cases these interventions were associated with three dimensions of access (approachability, availability and affordability) and reduction of hospitalizations (four/four studies), emergency department admissions (six/six studies), and unmet healthcare needs (five/six studies) (number of studies with a positive outcome/number of studies assessing this outcome). Various research designs were used: non-randomized (n = 7), randomized controlled (n = 1), quantitative descriptive (n = 1), and mixed methods (n = 1). These 10 studies were reported across 12 papers (Table 1) [26, 29, 31, 33, 34, 41, 42, 46, 53, 56, 64, 65].

Table 3 Pattern dimension-outcome

A possible subpattern has been found in the category of organizational interventions "Continuity of care via case management": reduction of unmet health care needs in the studies associated with two dimensions of access - approachability and availability [27, 32, 36]. Non-randomized (n = 2) and randomized controlled (n = 1) designs were used. However, considering a limited number of identified studies a conclusion on the 'dimension-outcome' pattern cannot be made.

Discussion

This scoping review included 39 studies of organizational interventions aimed at improving access to primary care for vulnerable populations (patients with chronic conditions and socioeconomically disadvantaged people), which have evaluated the impact of these interventions on hospitalization, emergency department admission, or unmet health care needs. Results revealed one ‘dimension-outcome’ pattern: the formal integration of services in which the reduction of hospitalization, emergency department admission and unmet health care needs was associated with three dimensions of access (approachability, availability and affordability), specifically for patients with low income or uninsured, patients with mental health problems, and elderly patients with multiple chronic conditions.

Formal integration of services means bringing all primary medical and social service providers together, typically with mental health service professionals, to meet the needs of the disadvantaged population. This is similar to ‘seamless care’ in inter-professional education (transversal integration) and inter-organizational pharmaceutical care (vertical integration) where students from multiple health disciplines, hospital and community pharmacists, formally do teamwork together, respectively [68, 69]. This also refers to ‘shared care’ or ‘collaborative care’ in mental health for instance, which consists of “a structured system for achieving integration of care across multiple autonomous providers and services with both primary and secondary care practitioners contributing to elements of a patient’s overall package of care” where “mental health experts work with first-line care providers in the delivery of mental health promotion, illness prevention, detection and treatment of mental illnesses, as well as rehabilitation and recovery support [70, 71].” For example, in the identified intervention studies formal integration was mainly done through teams including both primary care physicians and specialized health service providers in mental health, alcohol and substance abuse, and home care programs. An illustration of formal integration is a medical home (called Family Medicine Groups in Quebec or Family Health Teams in Ontario, Canada) when parents in situation of vulnerability are informed about all available services (approachability) to get them in time (availability) and free (affordability) including transcultural child mental health support if needed [72].

Our results indicate that the most commonly evaluated dimensions of access were approachability, availability and affordability for interventions targeting vulnerable populations. The most commonly evaluated type of intervention was continuity of care via case management; this type was not associated with a reduction of hospitalization and emergency department admission, although we did find in a recent systematic review that this type of intervention is effective for elderly patients with dementia [16, 17].

In addition, our results suggest a research gap in looking at vulnerability and access to primary care services from a patient perspective. Specifically, a paucity of research regarding reduction of hospitalization, emergency department admission, and unmet service needs outcomes with regard to five types of intervention (clinical multidisciplinary teams, revision of professional role, continuity of care via arrangement for follow-up, institution incentive, and capitation). Moreover, this work suggests a need for more research on these outcomes as well as the acceptability and appropriateness dimensions of access.

Ultimately, patients’ and caregivers’ ability to identify healthcare needs, and to know where to access primary care, as well as the ability to engage with care in order to receive what is actually appropriate could be the crucial gaps in access for vulnerable populations in certain contexts. This illustrates the challenge of embedding patient’s self-efficacy in policies. This scoping review suggests it can be easier to target structural resources and clinical behaviors (supply-side perspective) to adapt services to the needs, expectations and abilities of patients, rather than to empower patients and caregivers to more broadly engage in care access, which is what the Australian-Canadian IMPACT program is seeking to accomplish.

While only one ‘dimension-outcome’ pattern was found in this review, the limited number of included studies on patients in situation of vulnerability and the theory-driven approach may have precluded finding others. For example, we found few studies on the three outcomes of interest outside the formal integration of services and case management. This might reflect the fact that few innovations have been evaluated or published yet. For instance, several organizational innovations have been put in place in OECD countries to improve access to primary care (i.e., advanced access) [73]. Although numerous articles describe primary care organizational innovations for vulnerable populations, few report on the evaluation of these innovations. While three main databases were searched, subsequent systematic review may include an exhaustive search of evidence in multiple databases (including management databases, e.g., Health Business Elite), the grey literature, and citation tracking (e.g., in Scopus) with selection of bibliographic records and full-texts by two independent reviewers. However, the broad criteria of our search make it less likely that important articles were missed. Another implication for future review is derived from the focus of this scoping review on three outcomes and the limitation of the EPOC classification. Studies on other outcomes (i.e., health status) were excluded, while they can be considered. The EPOC classification of interventions pointed to key components of interventions, while other components can be considered. Various intervention elements appeared across different EPOC categories, suggesting the need for an inductive and finer grained typology of interventions to inform future practice. For example, the above-mentioned IMPACT program, led by the last four co-authors, is developing an inductive taxonomy of organizational interventions for improving access to primary care for vulnerable populations. This taxonomy could be useful for planning future research and reviews, improving practice and developing policies.

Conclusion

While there appears to be a limited number of published research studies about organizational interventions aimed at improving access to primary care for vulnerable populations, our scoping review showed that there are enough studies for a future systematic review to test the following hypothesis: formal integration of services (increased approachability, availability and affordability of primary care services) could be associated with a reduction of hospitalization, emergency room admission and unmet health care needs. Not surprisingly, our results also suggest approachability, availability and affordability could play an important role in access to care for vulnerable populations. Considering that this scoping review included all types of evidence, and suggests access to primary health care services for vulnerable populations could be improved by formal integration of services, future research can provide stronger evidence on finer grained types of interventions and other types of outcome.

Appendices

Appendix 1

Example of search strategy in Embase database

• 1. translational research/(5528)

• 2. integrated health care system/(6588)

• 3. Case Management/(7314)

• 4. Knowledge Management/(762)

• 5. exp quality control/(220922)

• 6. health care quality/(153298)

• 7. Organi?ational innovation*.tw. (71)

• 8. innovat*.ti. (14842)

• 9. Organi?ational change*.tw. (1807)

• 10. organi?ational model*.tw. (548)

• 11. (diffusion adj2 innovation*).tw. (504)

• 12. Integrated delivery system*.tw. (569)

• 13. Integrated Health Care System*.tw. (325)

• 14. Integrated Health* System*.tw. (544)

• 15. (program or programs or programme or programmes).tw. (468596)

• 16. medical care team*.tw. (56)

• 17. interdisciplinary health team*.tw. (11)

• 18. healthcare team*.tw. (1537)

• 19. health care team*.tw. (2704)

• 20. case management.tw. (7055)

• 21. managed care.tw. (15501)

• 22. knowledge management.tw. (838)

• 23. healthcare quality.tw. (1068)

• 24. health care quality.tw. (1756)

• 25. quality of health care.tw. (4484)

• 26. quality of healthcare.tw. (1334)

• 27. quality management.tw. (5531)

• 28. quality assurance.tw. (17475)

• 29. case coordination.tw. (25)

• 30. (intervention or interventions).tw. (582350)

• 31. multidisciplinary team*.tw. (12026)

• 32. or/1-31 (1321868)

• 33. health care access/(34233)

• 34. health care availability/(7450)

• 35. Healthcare Disparity/(5959)

• 36. exp patient attitude/(217912)

• 37. (availab* adj2 (healthcare or health care or health service*)).tw. (1393)

• 38. (access* adj2 (healthcare or health care or health service*)).tw. (9122)

• 39. access*.ti. (40638)

• 40. program* accessibility.tw. (20)

• 41. program* availability.tw. (62)

• 42. affordability.tw. (2214)

• 43. approachability.tw. (103)

• 44. appropriateness.tw. (13616)

• 45. or/33-44 (311948)

• 46. 32 and 45 (86444)

• 47. exp child health care/(47406)

• 48. exp community care/(63087)

• 49. Mental Health Services/(31280)

• 50. exp Primary Health Care/(86682)

• 51. General Practice/(43336)

• 52. child health service*.tw. (444)

• 53. infant health service*.tw. (16)

• 54. community nurs*.tw. (1833)

• 55. community mental health service*.tw. (588)

• 56. community health service*.tw. (551)

• 57. community pharmac* service*.tw. (123)

• 58. maternal health service*.tw. (246)

• 59. preventive health service*.tw. (361)

• 60. (senior center* or senior centre*).tw. (462)

• 61. (center* for the aged or centre* for the aged).tw. (334)

• 62. primary care.tw. (76389)

• 63. primary health care.tw. (11687)

• 64. primary healthcare.tw. (2676)

• 65. general practice.tw. (21225)

• 66. family practice.tw. (3694)

• 67. family medicine.tw. (6162)

• 68. or/47-67 (285192)

• 69. 46 and 68 (15001)

• 70. Vulnerable Population/(6013)

• 71. Poverty/(23599)

• 72. Unemployment/(7459)

• 73. Homelessness/(5938)

• 74. chronic disease/(97466)

• 75. mental disease/(118256)

• 76. exp *mental disease/(664947)

• 77. exp *aged/(16069)

• 78. frail elderly/(5142)

• 79. very elderly/(9994)

• 80. Minority Group/(8274)

• 81. Disabled Person/(12980)

• 82. exp "Drug Use"/(150974)

• 83. medically uninsured/(315)

• 84. illegal immigrant/(131)

• 85. immigrant/(8277)

• 86. indigent/(329)

• 87. lowest income grouup/(0)

• 88. medically underserved/(262)

• 89. refugee/(5352)

• 90. exp Terminally Ill patient/(4703)

• 91. vulnerab*.tw. (76118)

• 92. poverty.tw. (13629)

• 93. high risk population*.tw. (8227)

• 94. high risk patient*.tw. (28251)

• 95. complex patient*.tw. (1884)

• 96. complex need*.tw. (851)

• 97. sensitive population*.tw. (315)

• 98. disadvantaged.tw. (6913)

• 99. (underserved or under served).tw. (5638)

• 100. indigen*.tw. (18928)

• 101. tribes.tw. (2017)

• 102. native*.tw. (124764)

• 103. aboriginal*.tw. (5424)

• 104. low income.tw. (17600)

• 105. unemploy*.tw. (10051)

• 106. underemploy*.tw. (179)

• 107. homeless*.tw. (5781)

• 108. (street people or street person*).tw. (12)

• 109. social* stigma*.tw. (1141)

• 110. social* isolat*.tw. (4447)

• 111. inequalit*.tw. (13899)

• 112. uninsured.tw. (5190)

• 113. underinsured.tw. (459)

• 114. uneducated.tw. (402)

• 115. low educat*.tw. (4366)

• 116. poorly educated.tw. (260)

• 117. illitera*.tw. (3098)

• 118. chronic disease*.tw. (39799)

• 119. chronic* ill*.tw. (13506)

• 120. chronic condition*.tw. (10227)

• 121. aged.tw. (351635)

• 122. old.tw. (694632)

• 123. older.tw. (266367)

• 124. elderly.tw. (162147)

• 125. frail*.tw. (10361)

• 126. (senior or seniors).tw. (24681)

• 127. functional* impair*.tw. (12914)

• 128. disabled.tw. (13707)

• 129. disability.tw. (95888)

• 130. disabilities.tw. (28088)

• 131. handicapped.tw. (2633)

• 132. physically challenged.tw. (54)

• 133. mentally challenged.tw. (89)

• 134. mental disorder*.tw. (23602)

• 135. mental* ill*.tw. (21844)

• 136. psychiatric diagnos*.tw. (6839)

• 137. drug use*.tw. (42628)

• 138. drug abuse*.tw. (12151)

• 139. drug addict*.tw. (6598)

• 140. drug dependen*.tw. (4120)

• 141. drug habit*.tw. (69)

• 142. "substance use".tw. (19197)

• 143. substance dependen*.tw. (2410)

• 144. substance addict*.tw. (285)

• 145. uninsured.tw. (5190)

• 146. underinsured.tw. (459)

• 147. terminal* ill*.tw. (4662)

• 148. minority.tw. (38757)

• 149. minorities.tw. (6698)

• 150. immigra*.tw. (19128)

• 151. foreigner*.tw. (952)

• 152. refugee*.tw. (4336)

• 153. or/70-152 (2572418)

• 154. 69 and 153 (7631)

• 155. limit 154 to yr = "2000 -Current" (7118)

• 156. limit 155 to (english or french) (6891)

• 157. qualitative research*.mp. (29502)

• 158. qualitative stud*.mp. (18918)

• 159. action research.mp. (2607)

• 160. Participatory Research/(1916)

• 161. participatory research.mp. (3107)

• 162. case stud*.mp. (68678)

• 163. ethno*.mp. (67315)

• 164. grounded theory.mp. (6560)

• 165. phenomeno*.mp. (137337)

• 166. Narrative/(2274)

• 167. narrative*.mp. (16468)

• 168. biograph*.mp. (4728)

• 169. Autobiograph*.mp. (3202)

• 170. documentar*.mp. (1411)

• 171. qualitative synthes*.mp. (229)

• 172. active feedback.mp. (106)

• 173. conversation*.mp. (11040)

• 174. discourse*.mp. (9173)

• 175. thematic.mp. (10376)

• 176. qualitative data.mp. (6953)

• 177. key informant*.mp. (3676)

• 178. focus group*.mp. (25043)

• 179. case report*.mp. (1137960)

• 180. exp Interview/(123867)

• 181. interview*.mp. (240740)

• 182. exp Observational method/(1826)

• 183. observer*.mp. (52777)

• 184. visual data.mp. (249)

• 185. (audio adj record*).mp. (2581)

• 186. Cultural Anthropology/(32392)

• 187. experience*.mp. (670612)

• 188. or/157-187 (2271697)

• 189. exp clinical study/(4260567)

• 190. exp Methodology/(2712060)

• 191. randomization/(54544)

• 192. Placebos/(185259)

• 193. Crossover procedure/(35159)

• 194. or/189-193 (5940545)

• 195. (clinic* adj25 trial*).mp. (966368)

• 196. random*.mp. (862922)

• 197. control*.mp. (5237933)

• 198. (latin adj square).mp. (2318)

• 199. placebo*.mp. (243987)

• 200. or/195-199 (5877623)

• 201. exp Comparative Study/(666277)

• 202. comparative stud*.mp. (469566)

• 203. Validation Study/(44621)

• 204. validation stud*.mp. (50401)

• 205. evaluation research/(1614)

• 206. evaluation stud*.mp. (5068)

• 207. Follow-Up/(685736)

• 208. followup.mp. (21000)

• 209. follow-up.mp. (902021)

• 210. cross over.mp. (14288)

• 211. crossover.mp. (50503)

• 212. prospective*.mp. (548205)

• 213. volunteer*.mp. (132028)

• 214. or/201-213 (2089573)

• 215. singl*.mp. (1081892)

• 216. doubl*.mp. (392712)

• 217. trebl*.mp. (253)

• 218. tripl*.mp. (76252)

• 219. or/215-218 (1456962)

• 220. mask*.mp. (51854)

• 221. blind*.mp. (236161)

• 222. 220 or 221 (284003)

• 223. 219 and 222 (164051)

• 224. 194 or 200 or 214 or 223 (9418632)

• 225. exp Health Survey/(140568)

• 226. Health Care Survey/(5933)

• 227. exp Risk/(1311750)

• 228. exp Incidence/(231106)

• 229. exp Prevalence/(360569)

• 230. exp Mortality/(512165)

• 231. cohort*.mp. (395294)

• 232. case-control.mp. (122486)

• 233. cross sectional.mp. (214289)

• 234. (health* adj2 survey*).mp. (155311)

• 235. risk.mp. (1871315)

• 236. incidence.mp. (563598)

• 237. prevalence.mp. (512194)

• 238. mortality.tw. (486678)

• 239. "case series".mp. (43403)

• 240. "time series".mp. (24993)

• 241. "before and after".mp. (171898)

• 242. prognos*.mp. (514923)

• 243. predict*.mp. (1017431)

• 244. course*.mp. (614624)

• 245. or/225-244 (4558876)

• 246. (mixed adj5 method*).mp. (9599)

• 247. multimethod*.mp. (1003)

• 248. (multiple adj5 method*).mp. (22707)

• 249. or/246-248 (33153)

• 250. qualitative.mp. (135948)

• 251. Qualitative Research/(23741)

• 252. quantitative.mp. (442547)

• 253. or 251 (135948)

• 254. 252 and 253 (48559)

• 255. 249 or 254 (79725)

• 256. 188 or 224 or 245 or 255 (10841719)

• 257. 256 not (letter/or editorial/) (10370545)

• 258. 257 not (animal not human).sh. (10070426)

• 259. 156 and 258 (6064)

• 260. limit 259 to embase (4439)

Appendix 2

Table 4 Characteristics of included studies (local/regional intervention): Access dimension and outcome

Appendix 3

Table 5 Characteristics of included studies (state/national intervention): Access dimension and outcome