Introduction

On 28 March the General Dental Council (GDC) removed the requirement for a patient to first see a dentist before any treatment by a dental care professional (DCP). The decision was described as 'controversial' in the April 2013 edition of the BDJ, with support coming from The British Society of Dental Hygiene and Therapy, The British Association of Dental Nurses and The Office of Fair Trading, countered by strong reservations from the British Dental Association, which called the GDC's decision 'misguided'.1 The new arrangements came into force on 1 May 2013.

The GDC stressed that the decision was made with patient safety as the utmost priority, and that it followed a detailed review of evidence. An important component of this body of evidence came from a literature review on direct access in dental and other health fields commissioned by the GDC in April 2012. The review was intended to inform the GDC about any expansion of direct access evidence that may involve increased risk to patients, either by treatment or through failure to recognise and refer problems outside DCPs' clinical remit. This paper is an edited version of the results of that literature review, presented to the GDC in July 2012. The full Report may be found at http://www.gdc-uk.org/newsandpublications/research/pages/research.aspx

Background

Direct access has been legal for some years in a number of countries, US states and Canadian provinces, both for dental hygienists and, perhaps more controversially, for dental therapists, who are trained to perform a considerable range of restorative treatment otherwise undertaken by dentists. This summary focuses on three areas examined by the review:

  1. 1

    Evidence about the impact of direct access in jurisdictions where it operates, including risks and benefits to patients/clients and any other impacts for example, on attendance, patient/client attitude or the attitudes of other affected healthcare professionals

  2. 2

    Challenges that the introduction of direct access has presented in those countries and services, how relevant these are to dental services in the UK and any evidence of these challenges being managed and risks mitigated

  3. 3

    Completeness, robustness and credibility of the available evidence.

Methods

The literature review involved searching for studies evaluating or describing direct access arrangements or issues pertinent to such arrangements in both dental and other healthcare fields. Extensive enquiries were made to dental organisations worldwide. However, it should be noted that as the GDC commission was for a rapid evidence review, selection and grading of the relevant literature was not exhaustive. This is particularly true with regard to grey literature and to papers with restricted access. Searches were restricted to post-1993, the year of the Nuffield Report.2

We searched eight online sources of published literature (Medline, CinAHL, PsycINFO, SCI, SSCI, Cochrane Database of Systematic Reviews, Business Source Premier, Google scholar), representing a wide range of disciplines and journal types using a systematic search strategy. The team also made efforts to contact:

  • Educational institutions running dental hygiene/therapy and dental nurse training to identify aspects relevant to any extension of direct access to these practitioners

  • DCP professional associations in the UK and in countries where direct access has been instigated. For example, each US state has different arrangements regarding direct access to dental hygienists

  • Relevant bodies in other professions where direct access has been established, for example regarding nurse practitioners in the UK.

The reference lists of studies included in the review were scrutinised for any pertinent studies. Publications were checked independently by two team members, and a decision made as to their inclusion in the final review using criteria outlined in Table 1.

Table 1 Inclusion and exclusion criteria
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The initial screening stage resulted in a shortlist of articles including titles and abstracts. In the second stage, eligibility assessment was performed independently by two reviewers, with any disagreements being resolved by consultation with the third reviewer. The third stage involved retrieval of the eligible articles in full text. Final selection of the studies to be included in the review was further assessed and discussed within the team until consensus was reached. One reviewer extracted data from the included studies and a second checked the extracted data. Disagreements were resolved by discussion with the third reviewer.

Methodological quality was measured by reference to checklists developed by the Critical Appraisal Skills Programme (CASP)3 and the Scottish Intercollegiate Guidelines Network (SIGN).4 The use of such tools ensures the extraction of pertinent data to allow an appraisal of the overall methodological quality of individual quantitative studies as very poor, poor, moderate or good. In addition, the level of evidence was noted: ie Level I: systematic review (or meta-analysis) of all relevant randomised controlled trials; Level II: randomised controlled trial; Level III: (1) pseudo-randomised controlled trials (alternate allocation or some other method); (2) comparative but non-randomised studies; cohort studies; case control studies; interrupted time series with a control group; (3) comparative studies with historical control, two or more single-arm studies or interrupted time series without a parallel control group; Level IV: case series, either post-test or pre-test/post-test, non-comparative studies.

Qualitative studies set out to answer different types of questions, and it was therefore not appropriate to grade them alongside quantitative studies. We performed a global assessment of study quality, that is, strong, moderate or weak. Strong studies are likely to include triangulation of data, respondent validation, evidence of data saturation, clear exposition of methods of data collection and analysis, and reflexivity.

Results

Figure 1 shows the process of evidence identification and appraisal for the dental papers. One hundred and thirty-nine full text papers were retrieved and accessed for relevance. Of those, 35 were judged to have empirical evidence of sufficient relevance and quality for inclusion. These papers were then evaluated for quality using the appropriate CASP/SIGN checklists and the levels of evidence typology. The level of evidence ranged from Level III-2 to Level IV.

Figure 1: Flow chart of publications found via search of dental direct access literature.
figure 1

(One publication appears in both quantitative and qualitative groups)

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Figure 2 shows the results of the second search to identify non-dental health related papers.

Figure 2
figure 2

Flow chart of publications included from search of non-dental healthcare direct access literature

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Impacts, including risks and benefits

Evidence on the impact of direct patient access to GDPs comes predominantly from papers relating to the role of dental hygienists and dental therapists in the US. Nineteen studies from the US were reviewed, including six dealing with dental health aide therapists (DHATs) in the state of Alaska. Of the non-US papers, four relate to the UK, four to Australia, two to Norway, and one each to New Zealand, Sweden, Spain, Italy and Canada. Of the 35 papers, 23 deal with dental hygienists, 7 with dental therapists, 1 with dental assistants, 1 with denturists, and 3 with both hygienists and therapists. However, some papers did not examine direct access arrangements as such, but rather compared knowledge, clinical decision-making, costs etc pertaining to DCPs and dentists. As such they provide relevant information on the appropriateness of different professional groups assuming greater autonomy in their clinical activity.

Eight factors emerged from the review of dental studies as the potential major impacts, including risks and benefits, of introducing direct access.

Potential negative impacts

Risks to patient safety

In seven studies that examined aspects of patient safety,5,6,7,8,9,10,11 none provided any evidence of increased risk. Quality of evidence: moderate/good in five of seven studies.

However, two of these mentioned evidence of deficiencies in facilities and equipment, one in respect to radiographs,6 and another to sterilisation and equipment.8 Both these studies refer to the Alaska DHATs, who work in remote and under-served tribal localities. Quality of evidence: moderate/good in two of two studies.

Two descriptive Scottish papers do not present data directly pertaining to safety issues and extended duties dental nurses (EDDNs) acting under direct access arrangements.12,13 However, no significant adverse events have been recorded in this programme in over 168,000 fluoride varnish applications (personal communication, Childsmile Central Evaluation and Research Team, Glasgow Dental School, June 2012).

Risks relating to diagnosis and referral decision-making

Eleven studies were found that looked at the quality of DCPs' referral decision-making. Four found evidence of poor specificity (that is, referring a high proportion of problematic cases but also a significant number of non-problematic cases), leading to over-referral and unnecessary consultations.10,14,16 While one study noted good agreement between DCP and dentist regarding DCP referral decisions,17 others reported under-referral18 or problems in getting dentists to accept referrals.19 One US study reported good uptake of referrals by adult patients,20 but another reported a low uptake of referrals from a school dental service.15

Two European studies found knowledge and training deficiencies regarding oral cancer detection among dental hygienists,21,22 while a UK sample survey reported a lack of confidence among hygienists and therapists in their own ability to detect possible oral cancer.23 None of these three studies compared DCPs' knowledge with that of dentists. Quality of evidence: moderate/good in 10 of 11 studies.

Support to patients

Seven studies looked at aspects of DCPs' knowledge or support to patients regarding smoking cessation,21,22,24,25, diabetes26, child abuse27 and domestic violence.28 All but one24 found deficiencies in DCPs' knowledge or support to patients, but there is no evidence from these studies to suggest that dentists were any better in these respects. Quality of evidence: moderate/good in five of seven studies.

Concerns and lack of knowledge of professional and patients regarding direct access.

Both dentists and patients in several studies have shown mixed views about DCPs providing treatment. These findings contradict the conclusions of studies involving patients of DCPs (see 'patient satisfaction' below). Studies conclude that the introduction of direct access will require education and the preparation of information for health professionals, patients and parents.23,29,32 Quality of evidence: moderate in five of five studies.

Potential positive impacts

Increased access to dental care, both preventive and restorative

Ten studies provide evidence that the deployment of dental therapists and dental hygienists (and in one study, dental assistants) in indirect or general supervision or unsupported by a dentist resulted in greater access to and use of dental services by under-served groups and communities.6,8,15,19,20,33,37 Quality of evidence: moderate/good in seven of ten studies.

There is a limited amount of evidence regarding the work of dental nurses or dental assistants. One study examined the impact on access of a new type of dental assistant ('scaling assistants') in Maine, US,37 and concluded that workforce data suggested an increase in access to dental care. In the UK, EDDNs may effectively act under direct access in limited settings of day nursery and primary schools, in that they provide preventive care, including fluoride varnish treatment, with only general supervision from a dentist. Routinely collected monitoring data from the Scottish Childsmile programme12,13 indicate that in addition to any gain in the protection of children's teeth, access to restorative care is likely to have been increased. In over 108,000 appointments for fluoride varnish application completed in 2011, 22% resulted in parents being recommended to take their child for care from a dental practice, usually because untreated caries had been detected by the EDDNs (Personal communication, Childsmile Central Evaluation and Research Team, Glasgow Dental School, June 2012).

Cost savings to patients and the public purse

Three studies10,38,39 suggest variable and at most modest benefits regarding cost savings to the patients and service providers. Quality of evidence: moderate/good in two of three studies. The evidence for savings in dentists' time or other resources is inconclusive.20,37,38 Quality of evidence: moderate in one of three studies.

Patient satisfaction

Six studies gave consistent findings that patient satisfaction was high and/or dental anxiety low among dental hygienist and dental therapist patients.15,33,35,36,40,41 Two report higher satisfaction among patients of independent dental hygienist practices than among dentists' patients.33,41 Quality of evidence: moderate/good in four of six studies.

Higher job satisfaction among dental therapists and hygienists

One US and one UK study found that job satisfaction was higher when DCPs worked to their full remit and training.19,23 Quality of evidence: moderate in two of two studies.

Challenges/mitigation of risk

Potential barriers to direct access identified through the direct access literature search relate to practitioner and patient attitudes towards an extended DCP role. Attitudes among both dentists and patients tended to be more positive with direct experience of working with or being treated by DCPs, and DCPs themselves were confident in their abilities to work more independently.23,30,32,42 Five approaches to the mitigation of risk were identified:

Limitations of clinical remit, patient groups or settings.

Commonly limitations of the DCPs' clinical remit relate to restorative treatments, particularly those classed as 'irreversible.' There are examples of such limitations being widened over time or varying according to levels of experience, training or supervision. In some models patient groups have been limited to children, the elderly, the under-served (defined by the spatial distribution of dentists and their patient base), those on welfare benefit (for example, Medicaid, Medicare). Specified settings are commonly public service clinics or walk-in centres (as opposed to private practice), schools, care homes or other residential settings. There was no found evidence demonstrating the value of restriction by patient group or setting.

Stipulated levels of experience, qualification or training

Some models of direct access have stipulated levels of experience, qualification or training required by DCPs working independently or under general supervision. Again no evaluation material has been found which tests or compares restrictions of this kind.

Formal supervision

Formal supervision by dentists is a common, but not universal, method of regulating DCPs working directly with patients. These arrangements may involve a 'named dentist', as in the Alaska DHAT model. This dentist monitors activity, provides advice by telephone or audio-visual link, and accepts referrals.

Audit and inspection

Audit and inspection arrangements may exist outside supervision by a dentist. For example, the Alaska DHAT model maintains close audit returns of local performance.

Line management

DCPs may have a line management structure such as exists within the Childsmile oral health improvement programme in Scotland with its use of EDDNs working in schools and nursery schools, answerable to a programme coordinator and ultimately the Director of Dental Public Health within each Health Board.

These approaches to regulation and patient safety are by no means mutually exclusive, or limited to arrangements for direct access to dental care. For example, in the early 1990s the following limitations on practice in physical therapy (physiotherapy) direct-access models applied in different US states: diagnosis requirements, eventual referral requirements, physical therapist qualifications, patient consent requirements and practice setting restrictions.43

There is little evidence to evaluate or compare these approaches. However, a 2005 study found no reported disciplinary actions against dental hygienists in respect to the administration of anaesthesia across 13 US states over a ten year period.11

Gaps in the evidence

  1. 1

    Despite the fact that New Zealand is generally recognised as pioneering direct access to dental care provided by DCPs, particularly therapists and nurses, only one paper34 was identified that evaluated in that country. However, a 2012 review of the global literature on dental therapists includes a 58-page account of the development, organisation and performance of the New Zealand dental therapist profession44

  2. 2

    Evaluations of long-term outcomes of dental therapists' restorations were not found6

  3. 3

    Very little research evidence pertaining to dental nurses, dental technicians, and clinical dental technicians was found

  4. 4

    The research literature is dominated by papers from the US, a reflection both of recent developments in Alaska and elsewhere in response to poor access to dental care on the part of many Americans, and the controversy regarding safety and efficacy of independent 'mid-level' practitioners

  5. 5

    Only three research studies made reference to the referral pathway from DCP to dentist.15,19,20 There is a need for more detailed evidence on the extent to which patients and families fail to follow up referral to a dentist once they or their child has received treatment from a DCP, and the extent to which any such failure of referral is associated with treatment need

  6. 6

    There was insufficient relevant and good quality evidence to be able to evaluate different models of direct access with, for example, different levels of supervision. However, anecdotal evidence45 that US dental hygiene malpractice insurance premiums are the same regardless of the level of supervision the hygienist practices under, or the range of clinical services she performs, supports Scofield and colleagues11 in their conclusion that dental hygienists successfully and safely administer local anaesthetics to dental patients under varying supervision arrangements

  7. 7

    No research evidence on the operation of shared record keeping was found, although one study describes arrangements in the Alaska DHAT service.10

Direct access in other areas of regulated healthcare

As Figure 2 shows, the literature search identified seven areas of healthcare where some form of direct access has been reported. Three of these, and 40 of the 66 identified papers, relate to nurses working under direct access arrangements. This often involved primary care settings – probably the most useful comparison for dental services. A Cochrane systematic review46 on the substitution of doctors by nurses in primary care, although not explicitly defined as direct access, is also relevant to this review.

As patient safety was the prime concern of the GDC in commissioning the review, we restricted our summarising of this evidence base to issues of patient safety, including treatment and referral quality, in three areas felt to be most relevant to primary care-based dental services: direct access to nurses in primary care, including telephone triage schemes; physiotherapy; and audiology.

Overall the evidence from the eight nursing studies is favourable, in that six found no evidence that patient safety had been compromised by use of nurses or nurse practitioners.47,48,49,50,51,52 The systematic review by Laurante46 also reports no impact on health outcomes, but cautions about study quality. Moll van Charante et al. found considerable variation among nurses making telephone-based assessments and referral decisions.53

The evidence from physiotherapy studies on patient safety or referral quality is more mixed, with eight studies concluding that direct access does not pose a risk to public safety,54,55,56,57,58,59,60,61 three with equivocal findings,62,63,64 and three with at least partially negative findings.65,66,67 The main recommendation from this latter group was the need for relevant training to improve assessment and referral skills. The findings from the two audiology studies were very positive about patient safety and direct access to such services.68,69

Finally, we note the 2006 systematic review of evidence on extended roles for allied health professionals.70 While 21 studies progressed to full review and data extraction, the authors were unable to evaluate any pooled effects as patient health outcomes were rarely considered. They conclude that health outcomes, how best to introduce such roles, or how best to educate, support and mentor these practitioners, had rarely been evaluated (systematic review, evidence level I; study quality: good).

Conclusions

Over 100 research dental and other health-related papers were identified as relevant for this review of direct access. The quality of the evidence regarding direct access issues in dental care practitioners was varied but of moderately good quality as a whole. The material on direct access in dental services was overwhelmingly related to the work of dental hygienists and dental therapists, and mostly US in origin.

There was no evidence of significant issues of patient safety resulting from the clinical activity of DCPs. In contrast, there was strong evidence that access to dental care improved as a result of direct access arrangements, of cost benefits to patients, and of high levels of patient satisfaction. Of course, if access to dental care is widened, and appropriate referrals of patients with hitherto unmet treatment needs are made by DCPs to dentists, demands on dentists' services may rise. There was some evidence that DCPs may over-refer patients to dentists, which may ensure patient safety but lead to wasteful use of resources and a high level of 'no shows' on referral.

Finally, there is evidence of ongoing training needs to strengthen the assessment and referral skills of DCPs in respect to patients with other health problems or risk factors, but little evidence that dentist are any less in need of such training.