Utilising clinical settings to identify and respond to the social determinants of health of individuals with type 2 diabetes—A review of the literature

Abstract Type 2 diabetes (T2DM) is increasing in global prevalence. It is more common among people with poor social determinants of health (SDoH). Social determinants of health are typically considered at a population and community level; however, identifying and addressing the barriers related to SDoH at an individual and clinical level, could improve the self‐management of T2DM. This literature review aimed to explore the methods and strategies used in clinical settings to identify and address the SDoH in individuals with T2DM. A systematic search of peer‐reviewed literature using the electronic databases MEDLINE, CINAHL, Scopus and Informit was conducted between April and May 2017. Literature published between 2002 and 2017 was considered. Search results (n = 1,119) were screened by title and abstract against the inclusion and exclusion criteria and n = 56 were retained for full text screening. Nine studies met the inclusion criteria. Review and synthesis of the literature revealed written and phone surveys were the most commonly used strategy to identify social determinant‐related barriers to self‐management. Commonly known SDoH such as; income, employment, education, housing and social support were incorporated into the SDoH assessments. Limited strategies to address the identified social needs were revealed, however community health workers within the clinical team were the primary providers of social support. The review highlights the importance of identifying current and individually relevant social determinant‐related issues, and whether they are perceived as barriers to T2DM self‐management. Identifying self‐management barriers related to SDoH, and addressing these issues in clinical settings, could enable a more targeted intervention based on individually identified social need. Future research should investigate more specific ways to incorporate SDoH into the clinical management of T2DM.


| BACKG ROU N D
Diabetes prevalence has increased globally over the past three decades, with type 2 diabetes (T2DM) accounting for 85%-90% of all diagnoses (Diabetes Australia, 2015; World Health Organisation [WHO], 2016). People at socio-economic disadvantage are more likely to develop T2DM and are more susceptible to suboptimal selfmanagement due to the consequences of poor social determinants of health (SDoH) (Australian Institute of Health & Welfare [AIHW], 2014[AIHW], , 2016. This socially influenced health disparity suggests a need to investigate strategies to optimise healthcare provision so that social disadvantage and SDoH are acknowledged and incorporated into the standard practice of T2DM care. Social determinants of health are described as 'the societal conditions in which people are born, grow, live, work and age' (WHO, 2003). More specifically they include; early childhood development, education, employment, food security, housing, economic status, social support and healthcare access (Centres for Disease Control & Prevention [CDC], 2013;WHO, 2003). Social determinants influence both good and poor health. If a person is born into an affluent society with quality education, positive life circumstances, opportunity and healthcare access, the likelihood of good health is increased. To the contrary, when a person's lifespan is permeated with poor education, low economic status, unemployment, inadequate housing and limited access to quality healthcare, it is probable that their health status will be of poor quality, and they will have a shorter life expectancy (WHO, 2003).
Sustainable change towards improved SDoH requires political and social influence (Marmot & Wilkinson, 2006). Essential advocacy and action are underway at population and community levels (Keleher & MacDougall, 2016;Marmot & Wilkinson, 2006;Solar & Irwin, 2010); however while the approaches to address the causes of poor SDoH are occurring, the immediate and individual needs of people who live in circumstances contrary to a healthy life also require attention.
Despite the increasing prevalence of T2DM, especially amongst those at social disadvantage with poor SDoH (AIHW, 2014(AIHW, , 2016Diabetes Australia, 2015;WHO, 2016), there are currently no published guidelines on how to consider T2DM and SDoH simultaneously, particularly at a clinical level. Living with suboptimal SDoH impedes the lifestyle choices essential for effective T2DM self-management (Royal Australian College of General Practitioners [RACGP], 2016). Therefore, including strategies that identify and account for SDoH-related barriers may augment usual care by allowing additional interventions to be instigated as part of standard clinical practice. This may be an additional step towards improving health outcomes for people with T2DM.
Health services could embed SDoH as part of standard practice.
Identifying SDoH-related barriers to T2DM self-management could provide health professionals with insight into their clients' life circumstances. Understanding an individual's SDoH and the associated health disparities could then help health professionals to develop more contextualised interventions (Baum et al., 2013;Newman, Baum, Javanparast, O'Rourke, & Carlon, 2015). The limited guidance to enable such an approach is stemmed from an overall deficit of supportive policies, frameworks and structure (Baum et al., 2013).
This may also explain the lack of guidelines to incorporate SDoH into the clinical management of T2DM.
Although considering non-medical issues is not the main focus in clinical settings, the relationship between poor SDoH and the ability to self manage diabetes is supported by an extensive evidence base (Brown et al., 2004;Kumari, Head, & Marmot, 2004;Marmot, 2005;WHO, 2003). Therefore the formal incorporation of SDoH into usual clinical management of T2DM deserves more in-depth consideration and strategic progression.
Incorporating SDoH into T2DM clinical care; by identifying, considering and subsequently addressing the related self-management barriers could improve T2DM outcomes by enabling the ability to make the positive lifestyle choices required for effective T2DM self-management. This in turn, could help reduce the personal suffering that often accompanies the burden of living with diabetes.

| Aim of the review
This literature review aimed to explore methods and strategies used in clinical settings to identify and address the SDoH of individuals with T2DM. It is worth noting the word 'address' and its synonyms should not be interpreted as resolving the SDoH issue.
Instead, the correct interpretation is the strategies used to accommodate for the identified SDoH issue. For example, if it had been identified that a patient has limited transport options which would

What is known about this topic
• Social issues directly influence health, and are called social determinants of health (SDoH).
• Type 2 diabetes (T2DM) is more common among people with poor SDoH.
• SDoH are usually considered at a population level, not individually or clinically.

What this paper adds
• This is the first known literature review on how SDoH are incorporated into the clinical management of T2DM.
• Identified SDoH should be individually relevant, and considered a barrier to T2DM self-management by the person with T2DM.
• There is a gap in formal methods and strategies to incorporate SDoH into usual clinical care for people with T2DM. therefore impact their healthcare access, then arranging appropriate transport could alleviate the consequences of these SDoH issues.
The initial focus on identifying individuals' SDoH-related issues was to gain insight into what factors were included, and how and when SDoH identification could be incorporated into routine T2DM clinical care. Strategies and recommendations to address the identified SDoH issues were then explored to determine how the related barriers to T2DM self-management could be addressed.

| Systematic approach
The varied methodologies used in the reviewed studies (Table 3) indicated the suitability of an integrative approach to the literature review (Whittemore & Knafl, 2005), however it's iterative and interpretive nature is similar to that of a scoping review (Arksey & O'Malley, 2005

| Search strategy
The PRISMA protocol (Liberati et al., 2009) (WHO, 2003). This publication was considered important because it preceded an increasing evidence base concerning the influence of social determinants on health. The keywords were combined to obtain the primary search results.
Titles and abstracts were screened to ensure all of the included articles discussed clinical settings, identification and/or addressed the SDoH-related issues of individuals with T2DM. Incorporating the keywords (or their synonyms) identification* and/or address* into the search strategy appeared to eliminate pertinent articles, thus manual screening of titles and abstracts was necessary. After the initial screening and duplicate removal, the full text of the articles were read in brief. The inclusion and exclusion criteria were then applied to the remaining articles ( Table 2).
The search identified 1,244 articles. One hundred and twenty-five duplicates were removed, leaving 1,119 articles. Title, abstract and text screening reduced the remaining articles to 56. The inclusion and exclusion criteria were applied to these 56 articles.
Nine articles remained and were included in the review. Figure 1 outlines the process followed to identify, screen for eligibility and to include and exclude articles.

| Critical review, data extraction and analysis
Each study was critically reviewed using the McMasters critical appraisal tools for both quantitative and qualitative studies depending on the methodology used (Law et al., 1998;Letts et al., 2007). One study used mixed methods; therefore, both quantitative and qualitative McMasters appraisals were conducted for that study (Loh, Jaye, Dovey, Lloyd, & Rowe, 2015). The reviewed studies were then summarised and collated for comparison and interpretive analysis (Table 3). Commonly known SDoH (WHO, 2003) provided a reference for determining which SDoH were identified, and how frequently they were included (Table 4). The methods and strategies used to elicit this information were also ascertained during the study reviews (Table 5).

| General characteristics of studies
Seven of the nine studies included in the review were quantitative, one was qualitative and one used a mixed method design. Only one study intentionally investigated the value of identifying and addressing the SDoH-related issues of individuals with T2DM in a clinical setting. The remaining studies did not purposefully investigate identifying and/or addressing SDoH-related needs; however their methodology indirectly included these factors. Five of the nine articles were written by the same authors using the same data set. Each article reported separate interactions and relationships between T2DM and SDoH using different statistical analyses to investigate the specific issues considered in each study. Each study was published individually, and met the inclusion criteria for the current review. Consequently these five studies were appraised individually. All studies included a description of their ethics or approval procedures. Table 3 provides an overview of the articles included in the review.

| What was included?
Although identifying SDoH issues was not the primary focus for most of the reviewed studies, all embedded SDoH screening into their study protocol. Identification of social need was conducted as part of the study design or within participant descriptions, or both. Overall, SDoH factors included; income, employment, access to medical/healthcare, education, health literacy, social support, social exclusion, subjective social status (social gradient), serious psychological distress (stress), financial constraints, transport, food security, housing and early life.

| When and how was it done?
All studies completed the SDoH assessment prior to commencing the research protocol. Various approaches were used to gather the desired information. These were: written surveys (self-administered and assisted), phone surveys, health clinic databases and records, and medical chart entries. Table 5 provides a summary of the strategies and methods used to assess the SDoH-related issues of individuals.

| Addressing SDoH-related issues
Only one of the nine studies included specific strategies to address the identified SDoH-related needs of people with T2DM (Gimpel et al., 2010). The provided support was guided by the participant's identified social need obtained in the initial SDoH assessment.
Community health workers undertook a care coordination/case management role which involved assisting study participants to navigate the healthcare system independently. Examples of CHW assistance included arranging translation services, home visits, appointment reminders, supporting health education strategies, and teaching participants how to use public transport. Enrolment in the program also involved cost reduction of consultations and medications for participants. This strategy addressed financial constraints and issues associated with low income (Gimpel et al., 2010). Walker et al.'s five studies (2014aWalker et al.'s five studies ( , 2014bWalker et al.'s five studies ( , 2015aWalker et al.'s five studies ( , 2015bWalker et al.'s five studies ( , 2015 demonstrated multiple interactions and relationships between T2DM and SDoH. Consequently, they recommended SDoH be incorporated into T2DM management and interventions. Their recommendation did not provide any insight into how to address SDoH issues. However, the authors did recommend further Area/region identification* of SDoH issues rather than on an individual level

Published in a peer-reviewed journal
Policy/upstream approaches to addressing* SDoH (only) rather than on an individual level research be conducted to inform and improve self-care and outcomes for people with T2DM by incorporating SDoH-based strategies (Walker et al., 2014a). Use of the same data set for these five studies is acknowledged and discussed in the limitation section of this review.
The remaining three studies acknowledged the relationship between SDoH and T2DM; however none of the studies provided any specific recommendations or strategies about how to incorporate SDoH in into T2DM care (Loh et al., 2015;Rose, 2005;Rosland et al., 2014).

| D ISCUSS I ON
The aim of this literature review was to explore the methods and strategies used in clinical settings to identify and address the SDoH

| Identifying social need
Social determinants of health mean that the social factors in a person's life determine their health status and outcomes (Marmot & Wilkinson, 2006). The interdependent relationship between SDoH, T2DM and health outcomes was clear in Walker et al.'s five articles (2014aWalker et al.'s five articles ( , 2014bWalker et al.'s five articles ( , 2015aWalker et al.'s five articles ( , 2015bWalker et al.'s five articles ( , 2015. The SDoH factors they included were: income, education, subjective social status, serious psychological distress, access to healthcare and social support. Although Walker et al. (2014aWalker et al. ( , 2014bWalker et al. ( , 2015aWalker et al. ( , 2015bWalker et al. ( , 2015 demonstrated an unequivocal interdependence between T2DM and SDoH, they did not indicate whether the participants regarded the SDoH-related issues as barriers to effective T2DM self-management. In contrast, Gimpel et al. (2010) used focus groups to evaluate the effectiveness of CHWs employed to screen and address the social and economic concerns of individuals with, or at risk of T2DM and depression. Their SDoH screen was completed using a modified health risk assessment survey (

Rose (2005) also assessed patient views about barriers to
T2DM self-management. The study was undertaken to inform the development of a tool to measure the socio-economic barriers for people with diabetes. Participants in the study completed a phone survey, which used a five-point Likert scale to assess socio-economic barriers to diabetes self-management. The findings were inconclusive with sample size inaccuracy identified as a possible cause. Nonetheless, the author stressed the need to investigate the socio-economic impact on diabetes outcomes, and discussed the importance of continued progression on a reliable and valid measure of socio-economic barriers to diabetes self-care (Rose, 2005).
Employment and income were two of the most frequently assessed SDoH (7/9 and 9/9 respectively). These SDoH constituents are interrelated, because employment status can affect level of income, and insufficient income can increase financial constraints.
The three studies that included financial constraints (Gimpel et al., 2010;Rose, 2005;Rosland et al., 2014) incorporated the consequences of personal income status, which provided some insight into how this SDoH factor can be a barrier to T2DM self-management.
Lack of income and financial constraints also limit healthcare access when people cannot afford adequate healthcare (Keleher & MacDougall, 2016;WHO, 2003). Limited access to healthcare is a known barrier to achieving good health (WHO, 2011). All of the reviewed studies included access to medical/healthcare, which highlights the importance of asking people about their healthcare access, and prioritising it in an SDoH assessment.

Included in screening
Access to medical/healthcare 9/9 studies Ability to access health services is also limited by a lack of transport (Keleher & MacDougall, 2016; New South Wales Council of Social Service [NCOSS], 2012). This association is widely acknowledged throughout the literature (AIHW, 2016;WHO, 2011WHO, , 2003. Rosland et al. (2014) qualified this by including questions on how transport deficits contribute to reduced healthcare access. Despite the well-defined relationship between transport and healthcare access, only three studies included transport in their SDoH screening (Table 4).
Insufficient transport, employment and income can also exacerbate social exclusion as a lack of these can inhibit people's ability to access social networks (Keleher & MacDougall, 2016). Seven of the nine reviewed studies incorporated social support, and Healthy lifestyle behaviours are integral to optimal T2DM self-management (Egger, Binns, & Rossner, 2011;RACGP, 2016). In addition, effective diabetes self-management depends on adequate health literacy, which is augmented by quality education (Kim, 2016;Kim & Lee, 2016). Education is a widely recognised SDoH factor  Walker et al. (2014aWalker et al. ( , 2014bWalker et al. ( , 2015aWalker et al. ( , 2015bWalker et al. ( , 2015 and Rosland et al. (2014) used an assessment tool to measure social positioning. This SDoH assessment item was subjective, and asked individuals' to indicate their perceived position within society. It was not specified how this perception extended to T2DM self-management; however, social positioning has a well-known relationship with health status (Marmot, 2003;WHO, 2003) and renders it deserving of more in-depth investigation into the value of including it in an SDoH assessment.
Food security, housing, addiction and early life are also well recognised SDoH (AIHW, 2016;CDC, 2013;Marmot, 2003;WHO, 2011WHO, , 2003, as is their relationship with the self-management of T2DM (WHO, 2003;Yu & Raphael, 2004). Rosland et al. (2014) were the only authors to consider these SDoH factors. However because of their well-known association to health, their inclusion in an SDoH assessment requires also further exploration.
Stress is arguably one of the most critical aspects to consider when identifying an individuals SDoH (Marmot & Wilkinson, 2006;WHO, 2003)-related barriers to T2DM self-management. It can occur as a 'result of social and psychological circumstances' (WHO, 2003). The studies by Walker et al. (2014aWalker et al. ( , 2014bWalker et al. ( , 2015aWalker et al. ( , 2015bWalker et al. ( , 2015 and Rosland et al. (2014) incorporated stress in their SDoH assessment. They measured it in individually relevant terms; however the perceived impact of stress on T2DM self-management could not be interpreted.
Stress is increased with the coexistence of insufficient income, unemployment, social exclusion, inadequate transport, poor housing and food insecurity. This harmful accumulation of SDoH factors leads to people feeling they lack control over their lives (Keleher & MacDougall, 2016;WHO, 2003); in turn, this affects T2DM self-management (Brown et al., 2004;WHO, 2003;Yu & Raphael, 2004).
The evident multifactorial and interconnected nature of SDoH confirms that no single SDoH constituent works in isolation (Brown et al., 2004). Consequently, the convoluted and expan-

| Addressing the identified social need
Very few tangible strategies for addressing the identified SDoHrelated issues were identified. Individual SDoH circumstances and whether they were perceived as barriers to T2DM self-management appear to be central to how and what should be addressed. In addition, targeted and formalised integration of SDoH into clinical care through collaboration and partnerships between health services, community supports and social services is required (Baum et al., 2013;Freeman, Javanparast, Baum, Ziersch, & Mackean, 2018;Newman et al., 2015). Though this provides an informative starting point, further work in the area is needed, including the development of guidelines and policies (Baum et al., 2013). Appointing CHWs to focus on enhancing social support could help address SDoH-related barriers to T2DM self-management. This notion is supported by J. Freeman (2016) and McCalmont et al. (2016) who advocate for CHWs to work as part of the clinical team to address SDoH-related issues.

Community health workers in
It is also noteworthy that participation in the program discussed by Gimpel et al. (2010) included a cost reduction of medications and treatment services. This is an important inclusion, as it addresses barriers associated with limited income and financial constraints.
This strategy was depicted as an enabler to T2DM self-management by study participants.
Though not specific to T2DM, momentum towards addressing SDoH in clinical settings has commenced in Canada and the USA (Andermann, 2013(Andermann, , 2016(Andermann, , 2018Page-Reeves et al., 2016). In particular, the 'Community Links Evidence to Action Research' (CLEAR) collaboration incorporates SDoH factors in the toolkit they have developed. The CLEAR collaboration toolkit provides general direction on SDoH screening domains in clinical settings. It also outlines a 'patient level, practice level and community level' approach to addressing identified social issues (Andermann, 2013 issues, various social support activities, and assistance with literacy and comprehension (Hunt et al., 2011). The authors concluded that CHA's services are highly effective and valued by both participants and healthcare providers. Similar assistance was described in the reviewed study by Gimpel et al. (2010). The value of including CHW/CHA input to address SDoH-related issues for individuals with T2DM and in clinical settings appears persuasive and is well supported (Andermann, 2016;Gimpel et al., 2010;Hunt et al., 2011;Naz et al., 2016).
Supporting client literacy and comprehension is an integral role of a CHW/CHA (Gimpel et al., 2010;Hunt et al., 2011). People with lower levels of education are accurately presumed to have worse health literacy (Keleher & MacDougall, 2016;Kim, 2016;Wallace et al., 2010). The 'inability for individuals to access, understand, appraise and communicate health information within the healthcare system and the wider community' (Keleher & MacDougall, 2016) contributes to reduced healthcare access, suboptimal self-management (Welch et al., 2011) and contributes to a cascade of poor health outcomes resulting from poor SDoH. Poor health literacy leads to an inability to optimise diabetes education and support services, and therefore can lead to a deficit in diabetes knowledge and understanding. In turn, this can affect an individual's ability to achieve optimal T2DM self-management (Bains & Egede, 2011;Schillinger, Barton, Karter, Wang, & Adler, 2006). The quality of diabetes care is therefore dependent on a health professional's ability to accommodate for client health literacy levels (Wallace et al., 2010).
The benefit of including diabetes education that is sensitive to health literacy is supported by Kim and Lee (2016). Their systematic review and meta-analysis of 13 relevant articles focused on strategies to accommodate for patients with low health literacy.
They found an overall improvement in glycaemic management when health literacy was addressed. This provides convincing support for the integration of health literacy into diabetes self-management interventions (Kim & Lee, 2016;Wallace et al., 2010). Consequently manual screening of titles and abstracts was necessary prior to applying the inclusion and exclusion criteria. This may have limited the search, and is therefore worthy of acknowledgement.

| LI M ITATI O N S
Use of the same data set in the five articles by Walker et al. (2014aWalker et al. ( , 2014bWalker et al. ( , 2015aWalker et al. ( , 2015bWalker et al. ( , 2015 limited the breadth of the current literature review by reducing the total number of approaches used to identify the SDoH of individuals with T2DM in clinical settings. Although SDoH were only identified once, each study used different statistical analyses to describe separate interactions between SDoH and T2DM, and thus all were included in the review. Expanding the search to include other chronic diseases such as heart disease and stroke may have yielded more results, as the influence of SDoH on these conditions is also acknowledged (WHO, 2003), however this would have detracted from the specific focus on T2DM. Furthermore, this limitation also sheds light on the paucity of research currently done on SDoH in clinical settings, where T2DM is usually managed.

| CON CLUS ION
Social determinants of health and T2DM are interdependent, and inadequate self-management of T2DM is more common in those with poor SDoH (AIHW, 2014(AIHW, , 2016. Consequently the benefit of considering SDoH in conjunction with T2DM self-management was evident in the literature. The aim of the literature review was to explore methods and strategies used in clinical settings to identify and address the SDoH of individuals with T2DM. The literature did not reveal any specific guidelines; however, synthesis of the reviewed studies and associated literature revealed informative direction for future research.
Identifying social need in a clinical setting requires an individualised approach. Considering the individuals' personal circumstances and whether they perceive the SDoH-related issue as a barrier to T2DM self-management brings relevance to well-recognised SDoH. Thereby incorporating an individualised approach to assess SDoH-related barriers to T2DM self-management into clinical settings could enable a more targeted approach to usual clinical care.
Considering health literacy rather than education level may enhance the usability and application of SDoH assessments by allowing for improved comprehension of the terminology frequently used in T2DM care. Furthermore, accommodating for health literacy is crucial when identifying SDoH-related barriers, and when addressing SDoH-related issues. This combined with the expertise and skills of CHWs may be advantageous when devising strategies to incorporate SDoH into the clinical management of T2DM.
The impetus towards including SDoH in clinical settings has begun in Canada and the USA (Andermann, 2013(Andermann, , 2016Page-Reeves et al., 2016), and the strategies outlined in the CLEAR toolkit (Andermann, 2013) could be contextualised and then incorporated into the clinical management of T2DM.
Current efforts to advance T2DM management could be enhanced by incorporating innovative approaches that include the SDoH as part of standard clinical practice. Contextualising and progressing current approaches used in clinical settings to identify and address SDoHrelated barriers to T2DM self-management could enable this approach.
Furthermore, it is an opportunity to expand strategies that address SDoH and contribute to improved health equity in general.

ACK N OWLED G EM ENTS
The authors would like to thank James Cook University-College of Public Health, Medical and Veterinary Sciences for awarding a higher degree research grant to be spent on publication fees associated with this literature review.

CO N FLI C T O F I NTE R E S T
All authors declare that there are no conflicts of interest.

AUTH O R ' S CO NTR I B UTI O N S
The review was led by AF. SD and FB provided methodological guidance including design, search strategy, appraisal and synthesis of the reviewed articles. Literature searching was con-