Homeless adults’ access to dental services and strategies to improve their oral health: a systematic literature review

Globally, the oral health of homeless adults is poor (De Palma et al. 2005; Conte et al. 2006; Luo and McGrath 2006; Collins and Freeman 2007; Daly et al. 2010a; Simons et al. 2012; Figueiredo et al. 2013; de Pereira et al. 2014; Ford et al. 2014) and is reflected as observed need for restorative dental treatment (De Palma et al. 2005; Luo and McGrath 2006; Figueiredo et al. 2013; de Pereira et al. 2014; Ford et al. 2014), the presence of calculus or gingival bleeding on probing (De Palma et al. 2005; Luo and McGrath 2006; Collins and Freeman 2007; Daly et al. 2010a; Figueiredo et al. 2013; Ford et al. 2014). There is also a high need for emergency dental treatment by homeless adults (Conte et al. 2006; Figueiredo et al. 2013). In Adelaide, over two-thirds of homeless adults felt they needed dental treatment (Parker et al. 2011).

Having a need for dental treatment, does not always result in seeking care (Simons et al. 2012; Ford et al. 2014). Populations reliant on publicly funded dental programs are affected by system-level barriers to care. In the United States (US), dentists were discouraged from taking on Medicaid patients by poor remuneration rates, denial of claims and a high administrative burden (Nebeker et al. 2014). In Canada, a lack of dentists willing to accept publicly funded patients limited their access to care (Bedos et al. 2003). Cuts to US Medicaid dental programs resulted in an increase in dental presentations to hospital emergency departments, suggesting that dental care could not be considered as isolated from other healthcare systems (Cohen et al. 1996).

A better understanding of how and where homeless adults access dental care, the factors that prevent access and the strategies that have been used to promote oral health to that population will assist in the development of dental programs to facilitate regular preventive dental visits and improved oral health. In 2003, two review articles were published about homelessness and oral health; one in the United Kingdom (UK) (British Dental Association 2003) and one in the United States (US) (King and Gibson 2003). They highlighted the poor oral and general health of homeless people, the barriers they faced when accessing health care and suggested how dental access could be improved.

This review updates the literature describing programs to improve homeless adults’ access to dental services and to promote oral health.

1. How and where do homeless people seek dental care and advice?

2. What barriers prevent homeless adults from accessing dental care?

3. What strategies exist for the promotion of oral health to homeless people?

The review included studies written in English, based in developed countries, published after 2003, and that reported primary research focussing on homeless adults. Studies of young adults and adolescents were included if participants made independent oral health decisions. It excluded studies that focussed on homeless mothers making care decisions about their children’s dental care and homeless young children.

The MEDLINE via OvidSP, PubMed, Cumulative Index to Nursing Allied Health Literature (CINAHL) and Scopus databases were searched using Boolean operators and the following keywords: homeless, roofless, houseless, rough sleeper, couch surfer, shelter, hostel, dental and oral health.

The search was conducted by a single reviewer (J. Goode). After removing duplicates, the titles of the remaining studies were screened and irrelevant studies excluded. The abstracts of the remaining studies were reviewed for relevance by two reviewers (J. Goode, H. Hoang) before the full text was reviewed. Reference lists of the selected studies were searched for additional references.

The methodological quality of the selected studies was assessed and scored using the Mixed Methods Appraisal Tool (MMAT) (Pluye et al. 2011). Studies meeting all of the assessment criteria scored one; scores of less than one indicated that fewer criteria had been met (Pluye et al. 2011). Two reviewers (J. Goode, H. Hoang) independently assessed and rated the studies and any disagreements were resolved through discussion or with a third reviewer (L. Crocombe).

Data extracted from the reviewed articles included country, participant details, study design and a description of the findings that related to the three review questions. Extracted data were analysed and common themes were recorded and sorted to produce a narrative description of the theme.

From a pool of 235 articles, 22 met the inclusion criteria (Fig. 1). Quality analysis outcomes are reported in Tables 1–4. The characteristics and main findings of the studies are shown in Table 5. Eight studies were conducted in the UK, seven in the US, two in Australia, two in Canada, two in Ireland and one in Sweden.

Fig. 1.  Search strategy for the systematic review.

Table 1.  Qualitative critical review form analysis of seven studies

Table 2.  Quantitative critical review form analysis of three studies

Table 3.  Mixed-methods critical review form analysis of two studies

Table 4.  Quantitative descriptive review form analysis of 10 studies

Table 5.  Characteristics of selected studies of homeless adults’ access to dental services and strategies to improve their oral health

The review found that homeless people access dental care from dental practitioners (Hill and Rimmington 2011; Parker et al. 2011; Simons et al. 2012), students of dentistry (Lashley 2008; Seirawan et al. 2010; Abel et al. 2013) and dental hygiene (Rowan et al. 2013), doctors (Lashley 2008; Van Hout and Hearne 2014) and hospital emergency departments (EDs) (Robbins et al. 2010; Figueiredo et al. 2016). Dental visits were commonly made by homeless people for dental problems (Hill and Rimmington 2011; Parker et al. 2011; Coles et al. 2013). Problems were often self-managed using prescription or illicit drugs, alcohol or self-treatment (Van Hout and Hearne 2014). Alternatively, symptomatic relief was sought from doctors (Lashley 2008; Van Hout and Hearne 2014) or at an ED (Robbins et al. 2010; Figueiredo et al. 2016). In Toronto, homeless people were over twice as likely as people living on low incomes to attend an ED with a non-traumatic dental problem and almost half of those homeless people who did attend an ED for dental care made multiple visits (Figueiredo et al. 2016).

The inability to pay for dental care was the most cited factor preventing uptake of dental services (De Palma and Nordenram 2005; Robbins et al. 2010; Hill and Rimmington 2011; Parker et al. 2011; Simons et al. 2012; Ford et al. 2014; Van Hout and Hearne 2014; Caton et al. 2016). Knowing that safety net dental insurance would cover the cost of care increased the likelihood of seeking care by homeless adults (Robbins et al. 2010). The process of registering for government assistance, which enabled government-funded dental care, could be seen as onerous by homeless people (Simons et al. 2012; Van Hout and Hearne 2014).

In the US, over one-third of homeless adults did not know where to find dental care (Conte et al. 2006). Dental services were poorly advertised (Hill and Rimmington 2011; Rowan et al. 2013), but even when government-funded care was available and clinic location known, there was a poor uptake of care by homeless people (Ford et al. 2014).

Dental care can be a low priority for homeless people, especially during periods of drug and alcohol misuse (De Palma and Nordenram 2005; Van Hout and Hearne 2014; Caton et al. 2016). Homeless people were more likely to seek emergency rather than comprehensive dental care (Coles and Freeman 2016).

Psychosocial factors also affected the uptake of dental services by homeless people (Caton et al. 2016). Higher levels of dental anxiety and dental phobia were found in the homeless adult population than in the general population (Coles et al. 2011) and affected access to dental care (Collins and Freeman 2007).

The attitudes of dental health service providers to homeless people affected the uptake of services by homeless adults. Homeless adults reported being treated with a lack of respect (De Palma and Nordenram 2005) and having bad experiences at dental practices (Caton et al. 2016).

Several strategies have been developed to improve access to dental care for homeless adults, including the development of homeless-dedicated dental services (Seirawan et al. 2010; Hill and Rimmington 2011; Simons et al. 2012; Rowan et al. 2013). A key feature of these services was that dental service staff worked in close collaboration with homeless support agencies. Dental team members visited community centres, shelters and hostels to build and maintain good working relationships with support organisations (Simons et al. 2012; Caton et al. 2016).

Another important feature of dental services for the homeless was that they were located in close proximity to the homeless population. This involved delivering outreach dental programs, including on-site dental screening examinations at homeless hostels, shelters and drop-in centres (Lashley 2008; Simons et al. 2012; Caton et al. 2016). These programs gave the opportunity to identify treatment needs, provide oral hygiene advice and referral to a fixed-site clinic (Simons et al. 2012). On-site treatment was also provided using dental vans (Simons et al. 2012) and portable dental equipment (Simons et al. 2012; Abel et al. 2013). Fixed-site homeless dental clinics were co-located with other homeless health services to provide a ‘one-stop-shop’ for homeless health (Seirawan et al. 2010; Simons et al. 2012; Rowan et al. 2013).

Oral health care was also provided by universities (Lashley 2008; Seirawan et al. 2010; Abel et al. 2013; Rowan et al. 2013; Pritchett et al. 2014). Students of dentistry (Seirawan et al. 2010) and dental hygiene students (Rowan et al. 2013) provided care at fixed-site clinics within homeless support agency sites and postgraduate dental students used portable dental equipment to provide care within a homeless women’s shelter (Abel et al. 2013). Outreach screening examinations resulted in referral to university dental teaching clinics (Lashley 2008). Outreach programs involving dental (Pritchett et al. 2014) and nursing students (Lashley 2008) provided homeless adults with well-received oral health advice (Abel et al. 2013; Rowan et al. 2013; Pritchett et al. 2014).

In the US, homeless people who were engaged with drug rehabilitation and social welfare programs could receive extensive dental treatment, whereas those not engaged with programs could only receive emergency dental care (Seirawan et al. 2010). Homeless drug users felt that drug rehabilitation centres made good sites for dental clinics (Van Hout and Hearne 2014). However, delivering outreach dental services at hostels and shelters tended to exclude homeless people living in bed-and-breakfast accommodation and those aged over 40 years, and resulted in them having a poorer uptake of dental services compared to those living in shelters or using drop-in centres (Gray 2007).

Referrals to dental services were made by non-dental health professionals. Registered nurses who gave health checks referred clients to dental services. More referrals occurred from shelters employing nurses than from those shelters that did not (Gray 2007). The ‘Something to Smile About’ program (STSA) trained support agency staff to give oral health education and help connect homeless people with dental services. This had the potential benefit of building a network of oral health advocates who worked with homeless people on a daily basis. However, support workers felt their homeless clients had more pressing needs, such as food and shelter, and that those needs have priority over dental care. The STSA program failed to affect the most at-risk homeless group: single young adult males (Coles et al. 2013). Support workers involved in the STSA program found contact details of dentists who treated homeless people, oral health information leaflets and supplies of oral health products to be valuable resources (Coles et al. 2013). The STSA program highlighted the need for oral health messages to be delivered at an appropriate time and not at a time of crisis (Coles et al. 2013).

Homeless people can become overtaken by their ‘homeless identity’ (Coles and Freeman 2016, p. 58), making them less able to maintain oral hygiene and organise and attend dental appointments (Coles and Freeman 2016). During such periods, homeless people prioritised the short-term over the longer-term issues, making them more likely to seek emergency rather than preventive dental treatment (Coles and Freeman 2016). To accommodate this, dental services needed to be flexible and respond to the immediate needs of the homeless person (Caton et al. 2016). One aspect of this flexible approach was the ability for homeless people to drop in for care without an appointment (Simons et al. 2012).

Mobile dental services were expensive to set up and maintain, required extensive logistical planning and were prone to disruption from unexpected events, such as not being able to park the dental van due to roadworks (Simons et al. 2012). There were high rates of failure to attend dental appointments (Caton et al. 2016). Less than half of the homeless adults attending a mobile dental service in London completed their recommended treatment plan (Simons et al. 2012). Similar findings were reported for other dental services dedicated to homeless people (Seirawan et al. 2010; Hill and Rimmington 2011). Dental staff found missed appointments and incomplete treatment plans to be the least rewarding aspect of working with homeless people (Hill and Rimmington 2011). In the UK, missed appointments resulted in fines for some homeless individuals (Coles and Freeman 2016) or being excluded from some dental practices (Caton et al. 2016).

Service providers were also affected financially when emergency treatment was provided to homeless people who were unable to pay for their treatment and ineligible for free care (Simons et al. 2012). Support agency and dental support staff spent time and effort following up with clients, ensuring documentation was completed and encouraging attendance (Lashley 2008; Simons et al. 2012). The University of Southern California homeless dental clinic only provided comprehensive treatment for those enrolled in a rehabilitation or social welfare program. This reduced the number of missed appointments and improved the efficiency of the clinic (Seirawan et al. 2010).

This review found several barriers prevented homeless people from accessing dental care; cost, fear of the dentist or dental treatment, not knowing where to find dental care, feeling embarrassed about their teeth, dental care being a low priority, previous unpleasant experiences at the dentist and having to be registered to receive government benefits. Cost was the most commonly reported barrier to receiving dental care and when it was removed as a barrier, the likelihood of seeking care improved. Previous bad experiences at the dentist included the perception of feeling unwelcome. Dental services provided by students were well-received by the homeless population. However, there is evidence that dental student attitudes’ towards treating homeless people worsen as they progress through their dental course (Major et al. 2016) and that despite working with underserved populations as part of their university training, dentists were unlikely to treat homeless people as part of their everyday practice (McQuistan et al. 2010).

Dental service providers should not operate in isolation, but work collaboratively with other homeless service providers. This enables them to connect with the homeless population through an established network. The process of developing and maintaining collaborations and outreach programs was time-consuming, and constant effort was required to keep the services running effectively and efficiently.

In addition to being within the reach of homeless people, services need to be flexible, provide the opportunity to drop-in for an appointment and respond to the immediate dental needs of a homeless person. Drop-in appointments offer maximum flexibility, but may result in people having to wait, on the day, for an appointment, which, in itself, has been identified as a barrier to dental care (Jaafar et al. 1992; Daly et al. 2010b; Freeman et al. 2011).

Homeless people were more likely to attend non-emergency dental appointments when they were moving on from homelessness, such as when they were enrolled in a rehabilitation program. It is therefore important to maintain a connection with the homeless by visiting shelters and centres regularly to provide oral health advice, information about available dental services, screening examinations and oral health products.

This review was limited by the methodological quality of the studies included. The studies often had small convenience samples that increased the risk of selection bias. The transient nature of the homeless population made long-term follow up difficult. Studies were located in different countries, which meant that generalisations could not always be drawn regarding barriers and services. However, this review gave a valuable insight into how homeless people access dental services, the barriers they face and the strategies used by service providers.

The uptake of dental services by homeless adults was affected by cost, fear of the dentist, the perceived attitude of dental service providers and dental care being a low priority. Improving access to dental services for the homeless population requires collaboration with other support service providers, dental care being provided near the homeless populations and flexibility by dental service providers.

The authors declare that they have no conflicts of interest.