Discussion
Our study found a wide range of factors affecting the implementation and sustainability of interventions addressing oral health and related health behaviours among people experiencing SMD. By categorising the factors according to domains of the socioecological model,20 we attempted to provide a theoretical context to the study findings. The study found the need to reorient healthcare services for people experiencing SMD so that they acknowledge the inherent challenges of the people experiencing SMD better. Dedicated funding over a longer duration of time is essential to ensure specialist and sustainable health services are available for people experiencing SMD. Additionally, placing more trained staff, including support workers, can help provide a more targeted intervention for people experiencing SMD. Our findings emphasised the role of interpersonal factors (relationships between service providers and service users) as crucial in delivering and implementing health interventions. In addition to the presence of a positive relationship with the service providers, in terms of trust, mutual respect and non-judgemental communication, our study also found the need for the availability of training for healthcare providers. A systematic review of the global literature was conducted as part of our project to identify evidence on the implementation and sustainability of health interventions to improve oral health and related health behaviours in people experiencing SMD.21 This review reflects the findings of the present paper and finds moderate evidence that trust, resources and motivation levels are required to improve the implementation and sustainability of health interventions. Similarly, our findings related to training for staff were also found in a previous study that reported that ‘challenging behaviour’, of service users, often as a result of underlying social and health issues of people with SMD, can be a barrier in delivering the intervention.22
The location and time at which the health interventions are delivered to people experiencing SMD can make a difference in their implementation and sustainability. For instance, people experiencing SMD can find it challenging to access services very early in the mornings or later in the evenings, due to the timing of their jobs, probation appointments or even their preferences. Expecting people experiencing SMD to adhere to appointment times without understanding the inherent challenges faced by this group could set the interventions up for failure. A scoping review reiterates our findings and reports that rigid appointments were criticised in other studies and suggested that longer duration of appointments to address complex needs and flexible timings would make it easier for support workers and people experiencing homelessness to arrive at the health centres.23
At a more macrolevel, the intersection between health and housing has been widely and globally recognised as affecting people experiencing SMD.24 25 The interventions encompassing changes at the environmental, organisational and interpersonal levels will only be successful if they are implemented in cohesion with improving the social determinants of health. Housing-first interventions, especially those integrating housing with mental health interventions, have shown promise in helping people exit homelessness.26 Furthermore, issues related to oral health, other health conditions and health behaviours among people experiencing SMD were often dealt with and viewed separately by services and health professionals. However, these conditions often coexist and are interrelated. Unhealthy behaviours, such as smoking, alcohol and substance use, are associated with poor oral health27 28 and mental health conditions.29 There is also a link between mental health conditions and poor oral health status,30 which collectively are also linked to other chronic diseases.31 In such an overlapping plethora of disadvantages, there is a need to create an integrated pathway of care that addresses the health conditions of people experiencing SMD in a cohesive manner. The transient nature of people experiencing SMD, in terms of lack of fixed address, being in and out of prison and the complexities brought upon by mental health conditions and substance use—all need to be considered to make the interventions more implementable and sustainable. Recent National Institute for Health and Care Excellence guidelines recognise the need for targeted approaches and integrated multidisciplinary health and social care services for people experiencing homelessness, underpinned by co-design and co-delivery of services for sustained engagement with service users.32 Having trained staff could help with better patient preparedness, given that people with SMD can often present with multiple health conditions at the same time and may not necessarily have the same level of communication skills as some of the other patients. It is also important to give due importance to health promotion and preventative services in order to reduce the burden of unhealthy behaviours in people experiencing SMD. This has also been reflected in other UK and global literature, with studies finding that improved awareness about maintaining health and knowledge about the availability of interventions encouraged behaviour change through the active involvement of people experiencing SMD.33 34
Strengths and limitations
Our study brings to the forefront the need to inclusively tackle multiple disadvantages faced by SMD groups to improve their healthcare. By interviewing a large number of practitioner stakeholders across England, we attempted to cover the extensive experiences of people planning and delivering the interventions. Our study also captured insights from people experiencing SMD, who are often underrepresented in research. We involved their participation from the early stages of the project in setting up the study documents and recruitment strategies, as well as by including them as study participants. The themes and results generated from our study hence explored the perspectives of service providers and service users, ensuring that the recommendations represent the experiences of both. We also had multiple interviewers speak with both groups of participants. This ensured there was flexibility in the way the questions were asked and we could eliminate the chances of bias from any single interviewer. A limitation of our study was that we recruited fewer people with experience of SMD than service providers, which could have risked the themes being more defined by the experiences of service providers. We have, however, attempted to assess the themes from each participant group's perspective individually in order to draw comparisons and ensure representation from service providers as well as people with experience in SMD. We also acknowledge that there is limited representation in the sample of people experiencing SMD from ethnic minorities or non-English-speaking backgrounds and from regions in England other than North East England. Our sample included fewer females experiencing homelessness as compared with males. Previous evidence has shown that women often experience more hidden forms of homelessness and are therefore not as present in the same organisations or services that were used to recruit men.35 Females, ethnic minorities and non-English-speaking people experiencing homelessness might face unique challenges (such as less knowledge of services, challenges in accessing health interventions and barriers due to language), which merits further research. We found that people who were in the midst of experiencing challenging situations related to SMD provided less depth of data. Nonetheless, those further in the recovery journey were able to reflect on and provide useful insights. While some themes in our results, such as integrated and cohesive services, were more defined by perspectives about support for mental health and substance use, the same can also be extrapolated in relation to oral health and smoking cessation services. The benefits of integrating smoking cessation services with oral health have long been discussed.36 37 In addition, our study found very little information related to the implementation of diet-related interventions, which reflects the general paucity of interventions addressing poor diet in this population.
Implications and conclusions
We found that dedicated funding, integrated and inclusive services, trained healthcare providers, health promotion services and buy-in from service providers are important for the implementation and sustainability of interventions for oral health and substance use in people experiencing SMD.
Health interventions for people experiencing SMD need to be tailored or distinct from those that are aimed at the general population. A ‘one-size-fits-all’ approach to health and social care for people experiencing the combined effects of homelessness, substance use and repeat offending creates challenges as it does not account for the various socioeconomic difficulties of the SMD population. Treating homelessness as a public health issue, as well as a societal issue, is needed to reduce some of the disparity experienced by people experiencing SMD. Further research is needed to strengthen the evidence base for improving health outcomes for people experiencing SMD. This could focus on intervention development, co-producing interventions with people with experience of SMD and the evaluation of the implementation of interventions looking to improve oral health but also other aspects of health behaviours, especially interventions for improving diet.