A systematic review of oral health outcomes produced by dental teams incorporating midlevel providers

ASSOCIATION

REPORT

A systematic review of oral health outcomes produced by dental teams incorporating midlevel providers J. Timothy Wright, DDS, MS; Frank Graham, DDS; Catherine Hayes, DMD, DrMedSc; Amid I. Ismail, BDS, MPH, MBA, DrPH; Kirk W. Noraian, DDS, MS, MBA; Robert J. Weyant, DMD, DrPH; Sharon L. Tracy, PhD; Nicholas B. Hanson, MPH; Julie Frantsve-Hawley, RDH, PhD

ral health varies widely around the world and differs between specific segments of populations within individual countries. Dental caries is the most common chronic disease in children1 and adults,2 and in developed countries it disproportionately affects those of lower socioeconomic status. In the United States, the majority of the population has access to dental care. How-

O

Dr. Wright is the Bawden Distinguished Professor and the chair, Department of Pediatric Dentistry, School of Dentistry, The University of North Carolina, Chapel Hill. He also is the immediate past chair, Council on Scientific Affairs, American Dental Association, Chicago. Dr. Graham maintains a private practice in orthodontics in Teaneck, N.J., and is a senior attending dentist, Department of Dentistry, and senior attending dentist, Orthodontic Residency Program, Einstein College of Medicine, Montefiore Medical Center, Bronx, N.Y. Dr. Hayes is the director, Special Projects, Health Resources in Action, Boston. She also is a member of the American Dental Association (ADA) Critical Review Panel, ADA Center for Evidence-Based Dentistry, American Dental Association, Chicago. Dr. Ismail is the dean, Kornberg School of Dentistry, Temple University, Philadelphia. Dr. Noraian maintains a private practice in periodontics, Bloomington, Ill., and Urbana, Ill. He also is a member of the Council on Scientific Affairs of the American Dental Association, Chicago. Dr. Weyant is a professor and the chair, Department of Dental Public Health, School of Dental Medicine, University of Pittsburgh. He also is a member of the American Dental Association (ADA) Critical Review Panel, ADA Center for Evidence-Based Dentistry, American Dental Association, Chicago. Dr. Tracy is the assistant director, Center for EvidenceBased Dentistry, Division of Science, American Dental Association, Chicago. Mr. Hanson is a health science research analyst, Department of Scientific Information, Division of Science, American Dental Association, Chicago. Dr. Frantsve-Hawley is the senior director, Research Institute and Center for Evidence-Based Dentistry, Division of Science, American Dental Association, 211 E. Chicago Ave., Chicago, Ill. 60611, e-mail [email protected]. Address reprint requests to Dr. Frantsve-Hawley.

A B ST RACT Background. The authors conducted a systematic review on this research question: “In populations where nondentists conduct diagnostic, treatment planning, and/or irreversible/surgical dental procedures, is there a change in disease increment, untreated dental disease, and/or costeffectiveness of dental care?” Methods. The authors searched 12 electronic databases for articles published through February 2012 and hand searched relevant articles. They assessed the risk of bias of included studies and extracted data. Results. The authors screened 7,701 citations, resulting in 18 observational studies that met the inclusion criteria. They judged 13 of the studies to be at high risk of bias, five at moderate risk and one at low risk. The authors found no data regarding cost effectiveness, irreversible diagnostic procedures or diseases other than caries. Conclusions. The authors concluded that the quality of the evidence was poor. They found that in select groups in which participants received irreversible dental treatment from teams that included midlevel providers, caries increment, caries severity or both decreased across time; however, there was no difference in caries increment, caries severity or both compared with those in populations in which dentists provided all irreversible treatment. In select groups in which participants had received irreversible dental treatment from teams that included midlevel providers, there was a decrease in untreated caries across time and a decrease in untreated caries compared with that in populations in which dentists provided all treatment. Clinical Implications. Generalizability of results to populations other than those studied is limited owing to the age of some of the studies, as well as to clinical and methodological heterogeneity; consequently, the conclusions should be viewed with caution. Key Words. Access to care; American Dental Association; dental personnel; caries; dental auxiliaries; dental economics; dental public health; dental team; evidence-based dentistry. JADA 2013;144(1):75-91. JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 75

ASSOCIATION REPORT

ever, for substantial segments of the population in urban and rural areas, access to health care and dental care is limited.3 Organizations around the world involved in health care continue to explore mechanisms to improve oral health in the general population and reduce the marked disparities that continue to exist. Several determinants influence disparities in oral health, and access to dental care— although essential—is not sufficient to reduce these disparities. To address these issues in the United States, alternative models of dental care delivery have been proposed. Some workforce models include alternative dental providers who perform irreversible procedures, surgical procedures or both who historically have been called “dental nurses” or, more recently, “dental therapists.” The details of the entire scopes of practice of these providers are different for each country in which they work and, in many cases, have changed across time.4 For the purposes of this review, we will call these providers “midlevel providers”—any oral health care provider whose training and responsibilities are between those of dental team members recognized by the American Dental Association (ADA) (oral preventive assistants, dental assistants, expanded-function dental assistants and dental hygienists) and those of a licensed dentist. Although midlevel providers differ greatly in terms of supervision, training, populations served and scope of practice, all are intended to increase access to dental care and improve oral health, primarily of children. Researchers have conducted narrative4 and systematic reviews5,6 to evaluate midlevel providers. However, significant gaps remain in knowledge related to the impact of these providers on oral health outcomes and cost effectiveness. Given the diversity of health care delivery systems that exist around the world and the introduction of new and proposed oral health care delivery systems in the United States, on Oct. 13, 2011, the ADA House of Delegates mandated “that the American Dental Association, through the appropriate ADA agencies, conduct and report on a systematic review of the literature on non-dentist workforce models which exist or are under development in the [United States] and other countries that include diagnosis, treatment plan formulation and/or the performance of irreversible and/or surgical dental procedures” (midlevel providers), via Resolution 41H-2011.7 The ADA conducted the systematic review described here in response to that resolution. 76

JADA 144(1)

http://jada.ada.org

METHODS

This report summarizes the methods used to conduct the systematic review, including all details about the literature search, screening procedures, application of inclusion and exclusion criteria, rating of the evidence, assessment of the evidence and presentation of the contents of the evidence to the reader. The research question. On Oct. 28, 2011, the ADA Council on Scientific Affairs (CSA) requested the input of other ADA Councils, including the Council on Dental Practice; the Council on Dental Benefit Programs; the Council on Access, Prevention and Interprofessional Relations; the Council on Communications; the Council on Dental Education and Licensure; the Council on Government Affairs; and the Council on Ethics, Bylaws and Judicial Affairs to construct the research question for this systematic review. The CSA discussed the question at its meeting on Nov. 3, 2011. On Nov. 8, 2011, the Councils held a conference call to further refine the question and select members of the work group. The question as finalized by all interested parties was this: “In populations where non-dentists conduct diagnostic, treatment planning, and/or irreversible/surgical dental procedures, is there a change in disease increment, untreated dental disease, and/or cost-effectiveness of dental care?” The question focuses on evaluating workforce models that include midlevel providers who may have been trained to perform diagnostic, treatment-planning and surgical and restorative procedures. However, in practice, they also may have been trained to provide preventive and educational care. This review evaluates a model of provision of dental care that utilizes all of the potential services of midlevel providers. ABBREVIATION KEY. ADA: American Dental Association. AIAN: American Indian or Alaska Native. CEA: Cost-Effectiveness Analysis. CINAHL: Cumulative Index to Nursing and Allied Health Literature. CSA: Council on Scientific Affairs. dmfs: Decayed, missing or filled surfaces (in primary teeth). DMFS: Decayed, missing or filled surfaces (in permanent teeth). dmft: Decayed, missing or filled teeth (primary). DMFT: Decayed, missing or filled teeth (permanent). DT: Dental therapist. EURONHEED: European Network of Health Economics Evaluation Databases. HSRProj: Health Services Research Projects in Progress. ICS: International Collaborative Study. LILACS: Literature in the Health Sciences in Latin America and the Caribbean. RCT: Randomized controlled trial. SDS: School dental service. SIGLE: System for Information on Grey Literature in Europe. WHO: World Health Organization.

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT

Systematic review work group. After submission of information regarding potential panel members by other ADA Councils, the CSA selected seven panelists (referred to in this article as the “work group”) on the basis of their extensive experience in evidence-based dentistry to conduct this systematic review in collaboration with members of the staff of the ADA’s Center for Evidence-Based Dentistry (S.L.T., N.B.H., J.F.-H.). The work group of volunteers was chaired by a pediatric dentist in academia (J.T.W.) and also included three public health dentists (C.H., A.I.I., R.J.W.) and three dentists in private practice (F.G., K.W.N. and a third). All work group members submitted forms disclosing any conflicts of interest (the disclosed information is summarized at the end of this article). Literature search and screening procedure. Search methods for identification of studies. The work group developed a broad literature search strategy to maximize the likelihood of capturing all pertinent studies at the expense of also capturing unrelated studies. Examples of search terms are “dental therapist,” “dental nurse,” “dental assistant” and “dental hygienist.” Appendix 1 in the supplemental data to the online version of this article (found at http://jada.ada.org) lists the literature search terms and strategy. The work group, in collaboration with staff from the ADA Center for Evidence-Based Dentistry (S.L.T. and J.F.-H.), developed the search strategies. In January and February 2012, they searched the following electronic databases for peer-reviewed articles, gray literature and government reports: MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Literature in the Health Sciences in Latin America and the Caribbean (LILACS), Cochrane Database of Systematic Reviews, OpenGrey (System for Information on Grey Literature in Europe [SIGLE]-based), Scirus, Science.gov, Cost-Effective Analysis (CEA) Registry, European Network of Health Economics Evaluation Databases (EURONHEED), ClinicalTrials.gov and Health Services Research Projects in Progress (HSRProj). In addition, they contacted 20 organizations to request citations that could be applicable to the research question (Appendix 2 in the supplemental data to the online version of this article [found at http://jada.ada.org] provides a list of the organizations contacted). They also contacted government officers and researchers for aid in finding current data about the caries severity and untreated caries in patients

treated by midlevel providers and the current status of midlevel providers in the countries with studies included in this systematic review. They considered all submitted citations for inclusion. One author (S.L.T.) hand searched references of review articles and other relevant articles about dental workforce models to identify additional references for possible inclusion. Criteria for considering studies for this review (inclusion and exclusion criteria). The work group decided on broad inclusion criteria with the goal of capturing all pertinent studies. They included all study types (such as experimental, observational and descriptive studies) without placing limits on dates, age of study, language or country. They included peerreviewed publications, government reports and dissertations and theses. They excluded editorials, opinion pieces, educational pieces, narrative reviews, abstracts without full-text availability and raw data such as those from national oral health surveys. The work group included studies in which investigators evaluated populations of any demographic, including people of any age, sex, race, country or socioeconomic status who received diagnostic or irreversible oral health care from midlevel providers. The work group included studies even if their authors did not describe duties of the alternative provider explicitly in the article, but only if a term such as “school dental service” (SDS) was used and the country was known to employ dental therapists in the SDS. The work group excluded studies involving students in educational training programs. This review focused on irreversible and surgical procedures, so the work group excluded articles if the alternative providers performed only reversible procedures in the study. They considered cavity preparations and extractions to be irreversible or surgical procedures. They excluded studies regarding counseling and education, as well as studies regarding tobacco-use cessation and orthodontic auxiliary providers and denturists. They also excluded studies focused on alternative providers who screen patients as opposed to diagnosing disease. For a study to be eligible for inclusion, the work group required that it include a comparison group such as populations receiving irreversible care from midlevel providers versus those receiving no care or care by dentists, or populations receiving care from midlevel providers at two intervals (the first typically occurring before or early in the implementation of a program involving the use of midlevel providers, JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 77

ASSOCIATION REPORT

the second being a later period). The work group excluded studies in which investigators compared two groups treated by dental therapists and those in which investigators reported disease severity at a single point in time. The diseases of interest were caries, periodontal disease, oral cancer, trauma and malocclusion. Articles whose authors described oral health status also were eligible for inclusion. The work group excluded studies whose authors predicted future dental disease. Outcomes of interest were health outcomes (that is, disease increment or severity [as long as a comparison group was provided, such as two points in time] and untreated dental disease) and cost effectiveness. The work group excluded studies regarding the technical quality of restorations, as well as studies in which investigators reported patient or provider satisfaction. We defined the outcomes as follows: dDisease (caries) incidence is a measure of the number of people who develop new caries lesions within a specified interval. The incidence rate is the proportion of people in a defined population who develop one new caries lesion in a defined interval. One also may compute an incidence rate as the proportion of people in a population who had no disease (were caries free) at baseline but developed at least one caries lesion in a defined interval. dCaries increment is a measure of new caries lesions developed during a specified time interval, which is commonly measured as a change in decayed, missing because of caries or filled teeth or surfaces (either permanent [DMFT/S] or primary [dmft/s]). dCaries severity is a measure of the number of current and past caries lesions (decayed, missing or filled because of caries) in a person at a given time. It is expressed as DMFT/S or dmft/s. dCaries prevalence is the number of people with at least one caries lesion (decayed, missing or filled because of caries). The prevalence rate is the proportion of people in a defined population who have at least one caries lesion at a specific point in time. dCost effectiveness is the total cost of providing care (including training, salary, materials and overhead) and the effect of the care on the population’s disease burden. For caries, it is the total cost of saving one DMFT/dmft during a specified period and related societal costs (workforce, education and so forth). Screening and data extraction procedures. Two work group members screened each citation against the inclusion and exclusion 78

JADA 144(1)

http://jada.ada.org

criteria independently, then reviewed their findings in collaboration. The work group also developed a data extraction form, and two work group members extracted all data independently. Articles not available in English were reviewed for applicability to the project by dental experts with fluency in the language of the article. Assessments of risk of bias and quality of included studies. Quality of evidence encompasses a variety of factors, including risk of bias and study design. All included studies were rated for risk of bias independently and in collaboration (by one work group member and by N.B.H.) by using a checklist modified from the one published by Downs and Black,8 as shown in Appendix 3 in the supplemental data to the online version of this article (found at http:// jada.ada.org). The work group chose this checklist because it was a highly rated, validated checklist for assessing the risk of bias of observational studies.9 Table 18 delineates the criteria for categorizing the risk of bias for this review. If there were discrepancies between work group members in categorizing the risk of bias, a third rater (S.L.T. or J.F.-H.) arbitrated the scoring. Data synthesis. The work group intended to conduct a meta-analysis of the data if possible. Peer review. This systematic review underwent an extensive peer-review process that involved topic experts, evidence-based dentistry experts and stakeholders including representatives of state dental societies. Appendix 4 in the supplemental data to the online version of this article (found at http://jada.ada.org) lists all the reviewers and organizations that agreed to participate and returned comments by the designated deadlines. The ADA CSA approved the final manuscript of this article on Aug. 30, 2012. RESULTS

Description of the studies. Results of the search. The figure (page 80) shows the results of the literature search and screening process. The work group queried five major databases (MEDLINE, Embase, CINAHL, LILACS, Cochrane Database of Systematic Reviews), resulting in 5,070 unique citations. Three authors (S.L.T., N.B.H., J.F.-H.) and an assistant screened the titles and abstracts of these citations independently and in pairs according to the inclusion and exclusion criteria. Any citation that they selected for possible inclusion passed on to the next level of screening, following the philosophy of casting a wide net to find all relevant resources. In addition, S.L.T. searched seven supplementary databases and Web sites (OpenGrey,

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT

Scirus, Science.gov, CEA Registry, TABLE 1 HSRProj, ClinicalTrials.gov and Criteria for categorizing risk of bias in the EURONHEED) independently. included studies.* Because of the nature of searching and retrieving citations RISK OF BIAS FEATURES OF STUDY TYPE (METHODOLOGICAL from these databases, it was not QUALITY SCORE) possible for the work group memLow (19-27) Well-conducted randomized controlled trial (RCT) bers to screen these in collaborawith masked outcomes measurement tion. This process resulted in Observational study that includes a comparable 1,381 citations. S.L.T. also comparison group and provides adequate description of study population, sample size screened the titles and abstracts justification, statistical analysis (including power of the articles submitted by calculations and adjustment for confounding), clear external organizations, the artidefinition of exposures and interventions and outcomes, consideration of limitations, conclusions cles submitted or identified by supported by results and identification of funding government officials and source researchers and the articles idenModerate (10-18) Comparison study (including RCT) in which more tified by means of hand searches than one of the following domains are not adequately described: study population, sample size of references of relevant articles justification, statistical analysis (including power for possible inclusion. Much of the calculations and adjustment for confounding), literature that was found to be definition of exposures and interventions and outcomes, limitations, identification of funding related to this topic was in govsource, conclusions supported by results ernment reports and universityHigh (0-9) Cross sectional study at a single point in time based resources such as master’s Survey theses and dissertations, the Administrative record review majority of which was found by Comparison study in which several of the following domains are not described adequately: study hand searching reference lists. In population, sample size justification, statistical total, at least 24 manuscripts, analysis (including power calculations and containing an estimated 1,250 refadjustment for confounding), definition of exposures and interventions and outcomes, erences, were hand searched. limitations, identification of funding source and Combined, 7,701 citations were conclusions supported by results screened for inclusion or exclu* Modified from a scale by Downs and Black. sion. Of these, 7,190 were excluded. At least one author (S.L.T., N.B.H., J.F.-H.), alone or in conjunction whether the article addressed the question and with another author or a research assistant, met the inclusion criteria. Of these 193 studies, conducted full-text reviews of the remaining 511 the work group excluded 127. Then, working citations. Of these, 296 were excluded with reaindependently, one work group member and one sons, 21 could not be retrieved and one could not staff member of the ADA Center for Evidencebe translated within the given time frame. Of Based Dentistry (S.L.T. or N.B.H.) critically these excluded studies, 55 articles not available appraised and extracted the remaining 66 in English were reviewed for applicability to the studies. Forty-eight of these articles were exproject by dental experts with fluency in the cluded in face-to-face meetings and conference language of publication. The articles these calls. The final selection of 18 articles was made experts translated were published in Bulgarian, by means of a consensus process consisting of Dutch, French, German, Italian, Japanese, Norsecuring the majority agreement of the work wegian, Polish, Portuguese, Romanian, Russian, group through group discussion. Spanish and Swedish. The work group was Included studies. The literature search unable to retrieve 21 articles because some yielded 18 studies meeting the inclusion criteria, libraries that are not part of the ADA library’s as shown in Table 210-27 (page 81). The studies were conducted in Australia, Canada, Hong lending system (for example, libraries outside Kong, New Zealand and the United States. They the United States) did not fulfill the requests or included no data regarding diseases other than because some older publications were unavailcaries for which midlevel providers performed able because of their age. irreversible procedures. Similarly, they included The work group distributed among its memno data regarding the outcomes of interest for bers (J.T.W., C.H. or a third) the 193 studies midlevel providers performing irreversible diagthat were judged to be potentially relevant to nostic procedures such as excisional biopsies for the research question for consideration of 8

JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 79

ASSOCIATION REPORT

Unique records identified through primary electronic database (MEDLINE, Embase, CINAHL, LILACS, Cochrane) searching, screened by work group members independently according to title and abstract (n = 5,070)

Additional records identified through other sources (OpenGrey, scirus.com, science.gov, Cost Effectiveness Analysis Registry, HSRProj, Clinicaltrials.gov, EURONHEED) screened independently according to title and abstract (n = 1,381)

Reference lists of manuscripts hand searched (n = at least 24; references, n = at least 1,250), as well as submissions by government officials, stakeholders and researchers; screened independently according to title

Records excluded (n = 7,190)

Records screened (n = 7,701)

Full-text articles assessed for eligibility by work group members in pairs (n = 511)

Full-text articles excluded, with reasons (n = 296; number of those translated, n = 55) Full-text articles unable to be retrieved (n = 21) Full-text articles unable to be translated in the time frame (n = 1)

Articles excluded by work group members, with reasons (n = 127)

Articles reviewed by work group members in more detail for eligibility (n = 193)

Articles evaluated and discussed in face-to-face meeting and conference calls (n = 66)

Articles excluded in face-to-face meetings and conference calls (n = 48)

Studies included in qualitative synthesis (n = 18)

Figure. Literature search and screening process results. CINAHL: Cumulative Index to Nursing and Allied Health Literature. Cochrane: Cochrane Database of Systematic Reviews. EURONHEED: European Network of Health Economic Evaluation Databases. HSRProj: Health Services Research Projects in Progress. LILACS: Literature in the Health Sciences in Latin America and the Caribbean.

oral cancer. Lastly, they contained no data regarding these providers’ cost effectiveness. Table 34,28-30 (page 82) lists the countries with workforce models involving the use of midlevel providers for which we found studies meeting 80 JADA 144(1)

http://jada.ada.org

the inclusion criteria. Table 3 also includes the midlevel providers’ titles, the services they provided, the settings in which they were allowed to serve and the patients for whom they were allowed to provide care. The supervision of the

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT TABLE 2

Descriptions and risk of bias of the included studies. AUTHOR, YEAR

COUNTRY

SETTING AND POPULATION DESCRIPTION

RISK OF BIAS

Roder,10 1973

Australia

Schoolchildren, urban and rural, treated versus not treated through the South Australian School Dental Service (SDS)

Moderate

Roder,11 1976

Australia

Schoolchildren, state capital and country, treated versus not treated through the South Australian SDS

Moderate

Medcalf,12 1983

Australia

High school students from all five Western Australian SDS centers

High

Riordan and Colleagues,13 1993

Australia

Schoolchildren receiving care from Western Australian SDS compared with matched children receiving care from private dentists

Low

Gaughwin and Colleagues,14 1999

Australia

Comparison of high school students in South Australia involved in four dental care scenarios (SDS, private dental care, care by a variety of providers and no recent care for at least two years)

Moderate

Armfield and Spencer,15 2008

Australia

Children in the SDS throughout Australia

High

Curry and Colleagues,16 1974

Canada

Schoolchildren in the Oxbow pilot project compared with schoolchildren in other areas of Saskatchewan

High

Lewis,17 1981

Canada

Schoolchildren enrolled in the Saskatchewan Health Dental Plan receiving care in school clinics

High

Trueblood,18 1992

Canada

Indian and northern communities in Canada receiving care from dental therapists

High

Chan and Colleagues,19 1985

Hong Kong

Six schools comprising participants and nonparticipants in the School Dental Care Service

High

Lo,20 1987

Hong Kong

Primary schoolchildren from 53 schools participating and three schools not participating in the School Dental Care Service

Moderate

Chan and Colleagues,21 1990

Hong Kong

Primary schoolchildren participating and not participating in the School Dental Care Service

High

Fulton,22 1951

New Zealand

Schoolchildren from two provinces including both rural and urban settings and registered versus not registered in the SDS

High

Fulton,23 1951

New Zealand and United States

Children in the New Zealand SDS compared with children from seven areas of the United States

High

Davies,24 1959

New Zealand

Military servicemen having experienced dental treatment by five different provider combinations

High

New Zealand and United States

Schoolchildren from one community each in New Zealand (five schools) and the United States (three schools)

Moderate

Hunter,26 1984

New Zealand

Population oral health survey of schoolchildren in the SDS

High

Wetterhall and Colleagues,27 2010

United States

Five dental clinics in Alaska involving American Indian and Alaska Native children

High

Beck,25 1967

midlevel providers in each workforce model varied among, and sometimes within, countries. Although the work group implemented multiple search terms for “midlevel dental providers” (see details in Appendix 1 in the supplemental data to the online version of this article), they identified only studies regarding dental nurses and therapists that met the inclusion criteria. Because of the heterogeneity of the study types, comparison groups, countries of implementation and age of study, we could not combine the data in a quantitative manner. Furthermore, no statistical assessment of heterogeneity was possible. We have not provided information about sta-

tistical significance because statistical results often were not reported and, when they were reported, the investigators had used parametric statistical tests that did not account for clustered (caries) data or data that did not follow a normal distribution. The work group organized the results in tabular form according to outcome (caries severity and untreated caries) and categorized the studies according to the type of comparison the investigators had used (time series or comparison group). From these tables, the work group members assessed the data qualitatively to determine the conclusions and then discussed the conclusions until they achieved consensus. JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 81

ASSOCIATION REPORT TABLE 3

Titles and scopes of practice of midlevel dental providers, according to country.* COUNTRY

MIDLEVEL PROVIDER TITLE

SERVICES PROVIDED Diagnosis

Treatment Planning

Irreversible or Surgical Procedures

SETTING AND PATIENTS

Australia

Dental therapist (historically in some states, dental nurse)

Has varied across time, according to state and practice setting (public or private); some states allow

Has varied across time, according to state and practice setting (public or private)

Preparation of primary and permanent teeth for restorations; extraction of primary and permanent teeth depending on the state; emergency treatment for pulp exposure

School Dental Service: historically, children In some states, permitted to work in private dental practice and allowed to treat adults

Canada

Dental therapist (historically in Saskatchewan, dental nurse )

No

No

Preparation of primary and permanent teeth for restorations; extraction of primary and permanent teeth

Saskatchewan: a variety of settings; Manitoba: private practice; other provinces: First Nations reserves

Hong Kong

Dental therapist

No

No

Preparation of primary and permanent teeth for restorations; simple extraction of primary and permanent teeth

Government dental service (mainly School Dental Care Service); explicitly prohibited from private sector

New Zealand

Dental therapist (historically, dental nurse)

Yes

Yes

Preparation of primary and permanent teeth for restorations; extraction of primary and permanent teeth (before 1977, only primary teeth)4

Schools: historically, children to age 13 years; currently, children to age 19 years and adults (after receiving additional training and as part of a team in conjunction with dentists); can work independently with consultant supervision of dentist, but few do

United States (Alaska)†

Dental health aide therapist

Yes (standing orders in place)

Yes (standing orders in place)

Pulpotomies of primary teeth; uncomplicated extractions of primary and permanent teeth; atraumatic restorative treatment procedures,30 cavity preparation and restoration

Public health system, remote locations, Native Americans, underserved children and adults, patients with public insurance or no insurance

* Sources: Nash and colleagues,4 Lobene and Kerr28 and Nash and colleagues.29 † Source: Community Health Aide Program Certification Board.30

Excluded studies. Appendix 5 in the supplemental data to the online version of this article (found at http://jada.ada.org) includes a list of studies excluded at the full-text level of review, along with the reasons for their exclusion. Risk of bias of included studies. Table 2 summarizes the risk of bias of each included study. The work group judged 12 studies12,15-19,21-24,26,27 to be at a high risk of bias, five10,11,14,20,25 to be at moderate risk and one13 to be at low risk. Seven of the studies10,11,16,22-24 were published before 1980, five12,17,19,20,26 between 1981 and 1989 and the remaining six13-15,18,21,27 between 1990 and 2012. All of the data are from observational studies, most of which were either retrospective or cross sectional in nature. The work group found no ran82 JADA 144(1)

http://jada.ada.org

domized controlled trials in which the investigators evaluated the effect of various workforce models on health or cost-effectiveness outcomes. Effect of midlevel providers on disease increment (severity, DMFT). Investigators in seven studies reported results regarding caries increment or severity at a minimum of two periods in populations treated by dental therapists.12,15-18,24,26 The work group judged all of these to be at a high risk of bias. The studies were conducted in three countries: Australia, Canada and New Zealand. Table 412,15-18,24,26 summarizes the extracted data. The results of all of these studies showed a consistent trend of reduction in caries severity as measured with DMFT/dmft across time; however, the age of the

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT TABLE 4

Average caries increment and severity scores across time in populations treated by midlevel providers. STUDY, ACCORDING TO COUNTRY Australia Medcalf12 Armfield and Spencer15 Canada Curry and colleagues16 Lewis17

Trueblood18

New Zealand Davies24 Hunter26 * † ‡ § ¶ # **

PERIOD OF COMPARISON

SEVERITY MEASURE

PATIENT AGE (YEARS)

SEVERITY MEASURE RESULTS* Time Point 1

Time Point 2

Mean

No.

Mean (SD†)

No.

1978-1981 1977-2002

DMFT‡ DMFT

15 12

6.30 4.79

1,038 NR§

4.95 1.02

1,093 NR

1971-1973¶

dmft#/DMFT combined DMFT increment

7 to 13

4.70

NR

3.97

NR

Same cohort followed from age 6 to 9 All

0.96

NR

0.43

NR

0.20

NR

0.10

NR

1968-1970

1978-1988

Ratio of extractions to restorations

1980-1988

Ratio of restorations to preventive work

All

3.30

NR

0.91

NR

1954 versus 1958**

DMFT

18-21

18.5

196

17.3

62

1977-1982

DMFT

12-13

7.0

961

3.7 (2.7)

1,042

No investigators reported standard deviations unless included in the table. No investigators reported statistical significance. SD: Standard deviation, reported only for Hunter.26 DMFT: Decayed, missing or filled teeth (permanent). NR: Not reported. Groups receiving treatment by midlevel dental providers in the Oxbow region of Saskatchewan, Canada. dmft: Decayed, missing or filled teeth (primary). Patients who received regular treatment by dental nurses, but who did not receive any regular treatment by dentists thereafter.

studies and different environmental fluoride exposures limit the applicability of the results to the current U.S. population. Other potential confounding variables (such as population disease level and socioeconomic level) and modifying factors (such as duration of the study and location of the practice) not evaluated by the investigators (listed in Appendix 6 in the supplemental data to the online version of this article [found at http://jada.ada.org]) may have influenced these findings significantly. On the basis of these results, the work group concluded that in select groups who have received irreversible dental treatment by teams that included midlevel providers, caries increment and severity decreased across time. Investigators in 12 studies10,13,14,16,19-21,22-25,27 compared populations treated by dental therapists with another population. The other population was treated by dentists in private practice, had not received dental care recently or was undefined and described as not being enrolled in an SDS. One13 of the studies had a low risk of bias, four10,14,20,25 had a moderate risk

and seven16,19,21-24,27 had a high risk. These studies were conducted in five countries: Australia, Canada, Hong Kong, New Zealand and the United States (specifically, Alaska). Table 5 provides a summary of the extracted data. Of the six studies in which investigators reported statistical significance, the work group judged that one13 had a low, three14,20,25 a moderate and one21 a high risk of bias and that all five showed that populations receiving care from dental therapists had no statistically significant differences in caries severity (DMFT or DMFS) from that in populations not receiving treatment by midlevel providers (either not enrolled in an SDS, having received private care or not having received care recently). One study’s results showed no statistically significant differences for 10 of the 12 groups studied.10 The other studies had a high risk of bias, did not include reports of statistical significance and had inconsistent results (mixed,22,24 same but significance not reported,23 better16 or worse19,27). On the basis of these results, the work group concluded that in select groups who received irreversible dental treatJADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 83

ASSOCIATION REPORT

TABLE 5

Average caries increment and severity scores of populations treated by midlevel providers versus a comparison group. STUDY

COMPARISON

PATIENT AGE (YEARS)

MEAN DMFT* Midlevel Provider† Mean

(SD§)

Comparison Group‡

No.

Mean (SD)

No.

Statistical Significance

Australia Enrolled versus not enrolled in school dental service (SDS) (industrial area)

13-15 (age and sex pooled)

10.92¶

342

9.41¶

386

NR# for age and sex pooled data; however, four of six groups individually reported not statistically significant

Enrolled versus not enrolled in SDS (agricultural area)

13-15 (age and sex pooled)

10.90¶

308

10.39¶

259

NR for age and sex pooled data; however, all groups individually reported not statistically significant

Riordan and colleagues13

Enrolled versus not enrolled in SDS

12

0.95 (1.359)

100

0.71 (1.336)

100

Not significant (P = .077)

Gaughwin and colleagues14

Care by SDS versus care by private dentists

14-16

1.87** (SE†† 0.26)

130

2.57** (SE 0.38)

129

Not significant analysis of variance P > .05

2.37** (SE 0.54)

52

Roder10

Care by SDS versus no recent care (2 years)

Canada Dental therapists (DTs) in the Oxbow region of Saskatchewan, Canada, versus other areas of Saskatchewan served by dentists (1973 data)

7-13

3.97‡‡

544

4.57-5.44‡‡

NR

NR

Chan and colleagues19

Enrolled versus not enrolled in SDS

9-11

1.59¶

209

1.15¶

36

NR

Lo20

Enrolled versus not enrolled in SDS

9-11

1.1

392

1.0

254

Not significant

Chan and colleagues21

Enrolled versus not enrolled in SDS

9-11

0.76

167

0.76

118

Not significant

Curry and colleagues16

Hong Kong

* † ‡ § ¶ # ** †† ‡‡ §§

DMFT: Decayed, missing or filled teeth (permanent). See Table 3 for descriptions of the types of midlevel providers. See Table 2 for descriptions of the comparison groups in each study. SD: Standard deviation. Calculated from data reported in study. Weighted mean based on number of participants. NR: Not reported. Decayed, missing or filled surfaces (in permanent teeth). SE: Standard error. Decayed, missing or filled teeth (primary) and DMFT. Site E: A dental clinic in a small trailer adjoining a modern medical facility, served by one therapist who was based solely in the village and supervised by a dental director. This study site was judged to be the most representative site for comparison purposes. ¶¶ AIAN: American Indian or Alaska Native.

ment from teams that included midlevel providers, there was no difference in caries increment and severity compared with that in populations in which dentists provided all irreversible treatment. The work group members found no evidence that would enable them to determine the effect of the administration of irreversible or surgical procedures by midlevel dental providers on other oral diseases (such as periodontal disease or oral cancer). 84 JADA 144(1)

http://jada.ada.org

Effects of midlevel providers on untreated dental disease. The investigators in five studies12,15,16,24,26 compared untreated dental disease at a minimum of two time points in populations treated by dental therapists. The work group judged all of these to have a high risk of bias. The studies were conducted in three countries: Australia, Canada and New Zealand. Table 6 provides a summary of the extracted data. All studies show a consistent reduction in untreated caries as measured across time; how-

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT

TABLE 5 (CONTINUED)

STUDY

COMPARISON

PATIENT AGE (YEARS)

MEAN DMFT* Midlevel Provider† Mean

(SD§)

Comparison Group‡

No.

Mean (SD)

No.

Statistical Significance

New Zealand Fulton22

Enrolled versus not enrolled in SDS

7-14

5.52¶

4,072; each age group, 453-544

5.30¶

139; each age group 9-36

NR

Fulton23

New Zealand SDS versus seven cities in United States

12-14

8.6

1,455

6.3-9.3

514-14,920

NR

Davies24

Care by DT versus care by dentist (1954 data)

18-21

18.5

196

19.1

62

NR

18.5

34

NR

19.0

20

NR

18.2

28

NR

Care by DT versus no care (1954 data) Care by DT versus care by dentist (1958 data)

18-21

17.3

62

Care by DT versus no care (1958 data) Beck25

New Zealand SDS versus United States

12 (sex pooled)

9.39 (SE# 0.47)

101

9.48 (SE 0.51)

101

Not significant

9-10

85 percent prevalence

20

76 percent prevalence

283

NR

United States (Alaska) Wetterhall and colleagues27

Care by dental health aide therapist at Site E§§ versus unspecified care in AIAN¶¶ population in Alaska

TABLE 6 ever, the effect of confounders and modifiers as described in the preMean levels of untreated caries across time vious section is unclear. On the basis in populations treated by midlevel providers. of these results, the work group concluded that in select groups who STUDY, COMPARISON PATIENT MEAN LEVEL OF ACCORDING AGE (YEARS) UNTREATED CARIES* received irreversible dental treatTO COUNTRY ment by teams that included Time Point 1 Time Point 2 midlevel providers, untreated caries Mean No. Mean No. decreased across time. Australia The investigators in 13 studies Medcalf12 1978-1981 15 2.36 1,038 0.94 1,093 compared populations treated by Armfield and 1977-2002 12 2.33 NR† 0.48 NR dental therapists with another popuSpencer15 lation. The other population was Canada treated in private practices, had not Curry and 1971-1973‡ 7-13 2.90§ NR 0.98§ NR received dental care recently, or was colleagues16 undefined and described as not being New Zealand enrolled in an SDS. One13 of these Davies24 1954 versus 18-21 8.3 196 6.9 62 studies had a low risk of bias, 1958¶ 10,11,14,20,25 five had a moderate risk and Hunter26 1977-1982 12-13 0.2 961 0.1 1,042 seven16,19,21-24,27 had a high risk. These * No investigators reported standard deviations or statistical significance. studies were conducted in five coun† NR: Not reported. ‡ Patients receiving treatment by midlevel dental providers in the Oxbow region of tries: Australia, Canada, Hong Kong, Saskatchewan. New Zealand and the United States § Untreated caries in primary and permanent teeth. (specifically, Alaska). Table 7 pro¶ Patients who received regular treatment by dental nurses but who did not receive any regular treatment by dentists thereafter. vides a summary of the extracted data. The data concerning untreated caries according to provider type generally lations treated by midlevel providers than in the showed lower levels of untreated caries in popucomparison populations. Investigators in all JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 85

ASSOCIATION REPORT TABLE 7

Mean levels of untreated caries of populations treated by midlevel providers versus a comparison group. STUDY

COMPARISON

PATIENT AGE (YEARS)

MEAN NUMBER OF DECAYED TEETH Midlevel Provider*

Comparison Group†

Mean (SE‡)

No.

Mean (SE)

No.

Statistical Significance

Australia Enrolled versus not enrolled in school dental service (SDS) (industrial area)

13-15 (sex pooled)

3.57§

342

6.50§

386

NR¶ for age and sex pooled data; however, P < .01 for all groups in favor of SDS

Enrolled versus not enrolled in SDS (agricultural area)

13-15 (sex pooled)

3.56§

308

6.07§

259

NR for age and sex pooled data; however, P < .01 for four of six groups in favor of SDS

Enrolled versus not enrolled in SDS (rural)

Second-year high school students (13-15)

2.95-3.68

1,161

3.86-5.54

414

Statistically significant for four of six groups

Enrolled versus not enrolled in SDS (urban)

Second-year high school students (13-15)

1.79-2.67

258

2.93-4.88

320

Statistically significant for three of six groups

Riordan and colleagues13

Enrolled versus not enrolled in SDS

12

0.14

100

0.14

100

Not significant

Gaughwin and colleagues14

SDS versus private dentists SDS versus no recent care (for the preceding two years)

14-16

0.21# (0.05)

130

0.45# (0.13) 1.24# (0.41)

129 52

P < .05 according to analysis of variance between all groups

Oxbow region of Saskatchewan versus other areas of Saskatchewan combined, served by dentists (1973 data)

7-13

0.98**

NR

2.59-3.42**

NR

NR

Chan and colleagues19

Enrolled versus not enrolled in SDS

9-11

0.3§

209

0.7§

36

NR

Lo and colleagues20

Enrolled versus not enrolled in SDS

9-11

0.2

392

0.4

254

NR

Chan and colleagues21

Enrolled versus not enrolled in SDS

9-11

0.16

167

0.60

118

NR

Roder10

Roder11

Canada Curry and colleagues16

Hong Kong

* † ‡ § ¶ # ** †† ‡‡

See Table 3 for descriptions of the types of midlevel providers. See Table 2 for descriptions of the comparison groups in each study. SE: Standard error. Calculated from data reported in study. Weighted mean based on number of participants. NR: Not reported. Decayed surfaces (in permanent teeth). Decayed surfaces (in primary teeth) and decayed surfaces (in permanent teeth). Percentage with no decayed or missing teeth (permanent). Site E: A dental clinic in a small trailer adjoining a modern medical facility, served by one therapist who was based solely in the village and supervised by a dental director. This study site was judged to be the most representative site for comparison purposes. §§ AIAN: American Indian or Alaskan Native.

studies that had a moderate risk and all but one of the studies that had a high risk reported this result. The investigators in one study with a low risk of bias13 reported no statistically significant difference between populations treated by midlevel providers and those treated outside the SDS, and investigators in one high-risk-of-bias study24 reported mixed results depending on the 86

JADA 144(1)

http://jada.ada.org

year and the comparison group. On the basis of these results, the work group concluded that in select groups who had received irreversible dental treatment by teams that included midlevel providers, there was a decrease in untreated caries compared with that in members of populations in which dentists provided all irreversible treatment.

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT TABLE 7 (CONTINUED)

STUDY

COMPARISON

PATIENT AGE (YEARS)

MEAN NUMBER OF DECAYED TEETH‡ Midlevel Provider*

Comparison Group†

Mean (SE‡)

No.

Mean (SE)

No.

Statistical Significance

New Zealand Fulton22

Enrolled versus not enrolled in SDS

7-14

47.3-75.9 percent††

4,072; each group 453-544

16.7-55.6††

139; each group 9-36

NR

Fulton23

New Zealand versus seven cities in United States

12-14

0.89

1,455

2.5-5.6

51414,920

NR

Davies24

Care by dental therapist (DT) versus care by dentist (1954 data)

8.3

196

5.6

62

NR

8.4

34

NR

6.1

20

NR

7.4

28

NR

Care by DT versus no care (1954 data)

18-21

Care by DT versus care by dentist (1958 data)

6.9

62

Care by DT versus no care (1958 data) Beck25

New Zealand versus United States

12 (sex pooled)

2.74 (0.27)

101

7.12 (0.45)

101

NR

9-10

15 percent prevalence

20

39 percent prevalence

283

NR

United States (Alaska) Wetterhall and colleagues26

Care by dental health aide therapist at Site E‡‡ versus unspecified care in AIAN§§ population in Alaska

DISCUSSION

This systematic review focused on how the population’s oral health is affected by alternative dental workforce models that incorporate midlevel providers. The provider most commonly fitting this description was the dental therapist, formerly known in some countries as the “dental nurse.” Although dental therapists’ titles and scopes of practice vary among countries, these health care providers typically prepare and place restorations and perform extractions of primary and often permanent teeth, diagnose dental caries and, in most instances, work at some level under the supervision of a dentist. Many nations around the world have employed these types of oral health care providers during the past 90 years. The first and most studied program is New Zealand’s, which had its genesis shortly after World War I in an effort to help reduce oral disease and improve readiness of the future male fighting force.4 Of critical significance is the fact that the quality of the evidence identified in this systematic review was poor overall. Twelve (67 percent) of the 18 studies had a high risk of bias, five (28 percent) had a moderate risk and one study (5 percent) had a low risk. All studies were obser-

vational in design, and 39 percent of them wereconducted before 1980—an era in which fluoride exposure and preventive strategies differed from today’s. Most of the study populations were limited to children in school-based programs, and all studies but one were conducted outside of the United States. Because of these reasons, the generalizability of the results to the U.S. population is limited, and the results and conclusions of this systematic review should be interpreted accordingly. In select groups in which participants received irreversible dental treatment by teams that included midlevel providers, caries increment and severity decreased across time; however, there was no difference in caries increment and severity compared with those in populations in which dentists provided all irreversible treatment. In select groups in which participants received irreversible dental treatment by teams that included midlevel providers, there was a decrease in untreated caries across time and a decrease in untreated caries compared with that in populations in which dentists provided all treatment. The work group found no data related to the following domains: JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 87

ASSOCIATION REPORT

ddiseases other than caries for which midlevel providers performed irreversible procedures; doutcomes of interest for midlevel providers performing irreversible diagnostic procedures such as excisional biopsies for oral cancer; dcost effectiveness, which for the purposes of this study we defined as the real cost of reducing disease burden, of midlevel providers in conducting irreversible procedures. Oral health disparities and delivery of care. The research question addressed the outcomes of dental care at both the individual and targeted-population (such as schoolchildren) levels. At the individual level, the burden of untreated disease and disease increment are relevant outcomes. At the population level, however, overall health trajectories may not be changed by the provision of only clinical care and their change may require the addressing of social, behavioral and cultural norms, as well as economic and other determinants of oral health and overall health.31-33 The provision of oral health care in each nation occurs within a complicated infrastructure. This infrastructure can be designed with intention and can be highly controlled if financed by government; alternatively, it can have evolved by historical precedent. The major elements common to any nation’s oral health care infrastructure include a workforce (personnel such as dentists and hygienists), a delivery system (such as private dental offices and publicly funded clinics) and a financing system (such as public programs, private dental benefit programs, out-of pocket payment and charity care). The elements of the infrastructure interact with each other and with population oral health factors, geography, and political and cultural realities to produce, within each nation, an essentially unique system for delivering oral health care. The degrees to which each element of the infrastructure (personnel, delivery sites, financing) are planned and controlled by government vary substantially. On one end of the spectrum might be New Zealand, which features a high degree of central government control over workforce planning (in both the type of personnel and their numbers) and the financing of care. The other end of the spectrum would include systems such as that found in the United States, which lacks central government planning and operates primarily in the absence of substantial public funding for either the patient or the oral health care provider. Oral health care in the United States is delivered primarily through a private-payment health care system that is supplemented by government 88

JADA 144(1)

http://jada.ada.org

payment programs (such as Medicaid) and clinics that serve as a public safety net. We should note that the dental care infrastructure exists to some degree as a response to disease levels within a country. Historically, the highest caries rates in the world have been found in regions and nations with highly developed economies.34,35 The development of national-level workforce responses aimed at addressing these high disease levels in the past may not be appropriate today in light of drastically decreasing caries levels. Evidence from many sources (summarized in the World Health Organization’s [WHO’s] Country/Area Profile Project36) clearly documents that globally, caries levels have declined substantially (by as much as 80 percent) during the past 40 years in most developed nations. The importance of this evidence is twofold: this decrease has coincided with many changes in oral disease prevention and attitudes toward oral health, and this change has occurred irrespective of the workforce model in place. Two large international cross-sectional collaborative studies (International Collaborative Study [ICS] I34 and II35) sponsored by WHO during the periods of 1973 through 1981 and 1988 through 1992 were conducted to provide an intercultural comparison of various organizational models of oral health care delivery. One finding of ICS I34 was that the availability and accessibility of oral health services were not barriers to consumers. Thus, the hypothesis that increasing oral health personnel power would improve oral health status and reduce treatment needs was not supported by the data. In addition, community water fluoridation clearly was associated with substantially lower mean DMFT in children and students regardless of the provider system. No system or combination of system features was shown to be the answer to better oral health. The follow-up ICS II35 added that various types of fluoride are important for both children and adults and, for adults, if both patient and oral health care professional had a preventive orientation, it contributed to great improvement in the mean DMFT score. Although the oral health status of the U.S. population continues to improve as a whole and is as good as or better than that of many global populations, there remain substantial segments of the population who have unmet oral health care needs.2,37 The reasons for this inequity are complex and include issues related to oral health literacy; value placed on oral health; poor payment support from government programs;

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT

availability of oral health care providers who accept patients funded by government payer programs; transportation costs; time missed from work, school or both; and access to fluoridated water, among other issues. Unfortunately, oral health disparities exist regardless of the provider workforce model.3,38-41 In short, the contextual issues surrounding workforce modification are substantial and will need to be considered realistically as part of any attempt to improve access to care through the creation of new provider types. Furthermore, establishing and evaluating new workforce models should not preclude investigation of other strategies to improve existing disparities in oral health care. Dental caries is a difficult disease to cure, and restoring the sequelae of dental caries does not impede the progression of disease. One might infer that workforce models focused on treating the sequelae of dental caries (that is, placing restorations) will be less effectual in altering disease burden in the population than those focused on prevention and establishing a life course of health as opposed to disease intervention. For any program to be effective in managing oral health outcomes, prevention must be a primary focus. Strengths and limitations of this systematic review. The strengths of this review are that it was conducted by using the rigor of a systematic review and that it contains an assessment of the quality of the literature. The literature search was comprehensive, including electronic searches of five major databases, seven supplementary databases and several Web sites, as well as hand searches. We have identified gaps in the literature, and below we outline areas in need of future research. A limitation of this review is that it focused on health outcomes as opposed to access-related outcomes such as wait time or travel distance. However, this focus was intentional because, ultimately, positive health outcomes are the goal of any health care intervention.42 In addition, there is the possibility of bias arising from the unknown contents of the studies that we were not able to obtain or translate. Future research. A number of alternative workforce models are being considered or deployed in the United States that incorporate different types of midlevel providers. As the results of this review have shown, there is a paucity of high-quality literature to inform the questions regarding the effect these providers have on overall health outcomes and cost effectiveness. Despite this limited evidence, new workforce models incorporating midlevel

providers are being launched without robust evaluation plans or consideration of the environment needed for success. The work group recommends the research methods and objectives described below. dStudy design, conduct and reporting: The reference standard of clinical research is the randomized controlled trial. Theoretically, it is possible to design a cluster randomized controlled trial with one group treated by dental therapists and another group treated by another type of provider and measure both groups’ health outcomes and cost effectiveness. Prospective cohort studies are observational studies, which could measure differences in outcomes for patients treated by dental therapists versus other providers. Reporting that follows standard criteria43-45 is essential for transparency and future use. dHealth outcomes: Before (and at periodic intervals after) programs using new workforce models are launched, overall health outcomes (that is, disease severity and untreated disease) should be measured in addition to intermediate outcomes such as wait times, travel distance and retention of personnel who are trained and employed. It is critical to define all the goals of any program and specific measures to evaluate them a priori. Comprehensive evaluations may be expensive and time consuming; however, the inclusion of health outcomes data is essential to determine the success of the various models. dCost effectiveness: Because there are no current data regarding the cost effectiveness of midlevel dental providers in the United States, a comprehensive analysis concerning the total costs and their impact on improving oral health needs to be conducted. This analysis must address financial and economic viability issues for any new provider model, such as the number of new providers needed to make such a model successful and how reimbursement is affected by this model to allow for allocation of greater resources to the provision of care. dStudies in populations other than children: Little evidence exists regarding the effect of midlevel providers on other populations, including elderly people, people with special needs and other underserved populations. dFuture systematic reviews: Future research should be conducted to address the different effects of models focused on patient education and prevention and of those focused on the provision of irreversible and surgical procedures. In addition, future research should be directed toward evaluating the effects of school-based dental services that use different types of providers (midlevel providers and dentists) on JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 89

ASSOCIATION REPORT

outcomes of interest; the effect of midlevel providers on intermediate outcomes related to access to care; and the effect of midlevel providers on the treatment of dental disease and issues such as emergency department use, operating room use and time lost from school or work.

sory Committee of Kraft Foods, Northfield, Ill.; and is the director of the urban site of the American Dental Association Community Dental Health Coordinator project. Kirk Noraian is a member of the American Academy of Periodontology—American Dental Association Liaison Committee; he has material financial interest in Snoasis Medical Products, Denver; and he is a certified instructor for the Institute for Advanced Laser Dentistry, Cerritos, Calif. None of the other authors reported any disclosures.

CONCLUSIONS

The authors acknowledge the contributions of many people, without whose help this article would not have been possible: Elliot Abt, DDS, MS, MSc, attending dentist, Advocate Illinois Masonic Medical Center, Chicago, who was a member of the work group that conducted the review described in this article; Marko Vujicic, managing vice president of the American Dental Association’s (ADA’s) Health Policy Resources Center; staff of the ADA Division of Science (Kathi Alexandrakis, Carol Balabanow, Kat Dennis, Cameron Estrich, Sharon Myaard, Kathleen Todd, Erica Vassilos); staff of the ADA Library (Diane Bartkowiak, Jeff Gartman, Mary Kreinbring, Antanas Rasymas, Ruth Schultz). In addition, the authors thank those who helped translate foreign-language articles: Genevieve Koester, Kate Melcher, Victoria Ong, Kathryn Pulkrabek and Alex Spivak of the ADA staff, as well as Michael Glick, Kathy Kell, Aneta Lacek and Ivelina Petrova. Finally, the authors thank all the other people and organizations who contributed information, references and data for this review.

Eighteen studies from Australia, Canada, Hong Kong, New Zealand and the United States met the inclusion criteria. The work group judged 12 of these to have a high risk of bias, five to have a moderate risk and one to have a low risk. Seven of the studies were published before 1980, which is an era before the widespread use of fluoride toothpaste, community water fluoridation and contemporary caries prevention and management strategies. Six studies were published from 1990 through 2012. The work group judged the overall quality of evidence in the 18 studies to be poor. Generalizability of results to populations other than those studied is limited owing to the age of the studies and the studies’ clinical and methodological heterogeneity; consequently, the conclusions should be viewed with caution. The following is a summary of our conclusions: dThe quality of the evidence was poor. dIn select groups that received irreversible dental treatment by teams that included midlevel providers, caries increment and severity decreased across time. However, there was no difference in caries increment and severity compared with those in populations in which dentists provided all irreversible treatment. dIn select groups that received irreversible dental treatment by teams that included midlevel providers, untreated caries decreased across time and untreated caries decreased compared with that in populations in which dentists provided all treatment. dWe found no data in the following domains: diseases other than caries for which midlevel providers performed irreversible procedures; outcomes of interest for midlevel providers performing irreversible diagnostic procedures such as excisional biopsies for oral cancer; and cost effectiveness, defined as the real cost of reducing disease burden, of midlevel providers. ■ Disclosures. J. Timothy Wright is a member of the Council on Scientific Affairs of the American Academy of Pediatric Dentistry, Chicago. Frank Graham is a member of the American Dental Association American Dental Political Action Committee Board. Catherine Hayes is president-elect of the American Association of Public Health Dentistry, Springfield, Ill., and chair of the Better Oral Health for Massachusetts Coalition (a voluntary position at a nonprofit coalition), Boston. Amid Ismail is a member of the board of directors of SS White, Piscataway, N.J.; a member of the Global Oral Health Advi-

90 JADA 144(1)

http://jada.ada.org

1. Petersen PE, Bourgeois D, Ogawa H, Estupinan-Day S, Ndiaye C. The global burden of oral diseases and risks to oral health. Bull World Health Organ 2005;83(9):661-669. 2. Dye BA, Barker LK, Selwitz RH, et al. Overview and quality assurance for the National Health and Nutrition Examination Survey (NHANES) oral health component, 1999-2002. Community Dent Oral Epidemiol 2007;35(2):140-145. 3. U.S. Department of Health and Human Services; Office of the Surgeon General; National Institute of Dental and Craniofacial Research. Oral Health in America: A Report of the Surgeon General. Rockville, Md.: U.S. Department of Health and Human Services, U.S. Public Health Service; 2000. 4. Nash DA, Friedman JW, Mathu-Muju KR. A Review of the Global Literature on Dental Therapists: In the Context of the Movement to Add Dental Therapists to the Oral Health Workforce in the United States: Battle Creek, Mich.: W.K. Kellogg Foundation; 2012: 460. 5. Dasanayake AP, Brar BS, Matta S, Ranjan VK, Norman RG. Are procedures performed by dental auxiliaries safe and of comparable quality? A systematic review. J Calif Dent Assoc 2012;40(1):65-78. 6. Galloway J, Gorham J, Lambert M, et al. The professionals complementary to dentistry: systematic review and synthesis (structured abstract). University College London, Eastman Dental Hospital, Dental Team Studies Unit 2002:153. 7. American Dental Association. Resolution 41H-2011: ADA Scientific Review of Alternate Dental Workforce Models. In: American Dental Association. Transactions 2011. Chicago: American Dental Association; 2011:475-476. 8. Downs SH, Black N. The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions. J Epidemiol Community Health 1998;52(6):377-384. 9. West SL. Systems to Rate the Strength of Scientific Evidence. Rockville, Md.: U.S. Department of Health and Human Services, Public Health Service, Agency for Healthcare Research and Quality; 2002. AHRQ publication 02-E016. 10. Roder DM. The effect of treatment provided by dentists and therapists in the South Australian School Dental Service. Aust Dent J 1973;18(5):311-319. 11. Roder DM. The effect of treatment provided by dentists and therapists in the South Australian School Dental Service: the second report. Aust Dent J 1976;21(2):147-152. 12. Medcalf GW. The effect of school dental care on caries, oral hygiene, gingivitis, and calculus in Western Australian children. Aust Dent J 1983;28(4):239-242. 13. Riordan PJ, Dalton-Ecker L, Edwards TS. Dental status of 12year-olds treated in private practice and a school dental service. Community Dent Oral Epidemiol 1993;21(4):198-202. 14. Gaughwin A, Spencer AJ, Brennan DS, Moss J. Oral health of children in South Australia by socio-demographic characteristics and choice of provider. Community Dent Oral Epidemiol 1999;27(2):93-102.

January 2013

Copyright © 2013 American Dental Association. All rights reserved.

ASSOCIATION REPORT 15. Armfield JM, Spencer AJ. Quarter of a century of change: caries experience in Australian children, 1977-2002. Aust Dent J 2008;53(2):151-159. 16. Curry TM, McPhail CWB, Peacock GH, et al. Saskatchewan studies with the British dental auxiliary model. In: Lucaccini LF, Handley J, eds. Research in the Use of Expanded Function Auxiliaries: Report of a Symposium. Bethesda, Md.: U.S. Department of Health, Education, and Welfare; Public Health Service; Health Resources Administration; Bureau of Health Resources Development; Division of Dentistry; 1974: 25-41. DHEW publication (HRA) 75-14. 17. Lewis DW. Performance of the Saskatchewan Health Dental Plan, 1974-1980. Toronto: University of Toronto; 1981. 18. Trueblood GR. An analytical model for assessing the costs and benefits of training and utilizing auxiliary health personnel with application to the Canadian Dental Therapy Program (thesis). Montreal: Concordia University; 1992. 19. Chan SK, Chu YM, Lau WKJ, et al. A Study of the Hong Kong School Dental Care Service. Hong Kong: The University of Hong Kong; 1985. 20. Lo ECM. Dental Caries Among Hong Kong Children: A Socioepidemiological Study. Hong Kong: The University of Hong Kong; 1987. 21. Chan LK, Cheng ML, Fok KH, et al. A Study of the Hong Kong School Dental Care Services: A Comparison Between Users and Nonusers. Hong Kong: The University of Hong Kong; 1990. 22. Fulton JT. Experiment in Dental Care: Results of New Zealand’s Use of School Dental Nurses. Geneva: World Health Organization; 1951. 23. Fulton JT. Dental caries in New Zealand and the United States. Am J Pub Health Nations Health 1951;41(1):76-79. 24. Davies GN. The dental condition of compulsory military training recruits: third survey. N Z Dent J 1959;55:77-80. 25. Beck DJ. Evaluation of dental care for children in New Zealand and the United States. N Z Dent J 1967;63(293):201-211. 26. Hunter PB. The prevalence of dental caries in 12- and 13-yearold New Zealand children in 1977 and 1982. N Z Dent J 1984;80 (359):16-18. 27. Wetterhall S, Bader JD, Burrus BB, Lee JY, Shugars DA. Evaluation of the Dental Health Aide Therapist Workforce Model in Alaska: Final Report. Research Triangle Park, N.C.: RTI International; 2010:97. 28. Lobene RR, Kerr A. The Forsyth Experiment: An Alternative System for Dental Care. Cambridge, Mass.: Harvard University Press; 1979. 29. Nash DA, Friedman JW, Kardos TB, et al. Dental therapists: a global perspective. Int Dent J 2008;58(2):61-70. 30. Community Health Aide Program Certification Board. Standards and Procedures (Amended June 19, 2008). Anchorage, Alaska: Community Health Aide Program Certification Board; 2008. 31. Mokdad AH, Marks JS, Stroup DF, Gerberding JL. Actual causes of death in the United States, 2000 (published correction appears in JAMA 2005;293[3]:293-294). JAMA 2004;291(10): 1238-1245.

32. McGinnis JM, Williams-Russo P, Knickman JR. The case for more active policy attention to health promotion. Health Aff (Millwood) 2002;21(2):78-93. 33. U.S. Institute of Medicine; Committee on Health Behavior: Research Practice Policy. Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences. Washington: National Academy Press; 2001. 34. Arnljot HA, ed. Oral Health Care Systems: An International Collaborative Study. London: Quintessence on behalf of World Health Organization; 1985. 35. Chen M. Comparing Oral Health Care Systems: A Second International Collaborative Study. Geneva: World Health Organization and University of Chicago Center for Health Administration Studies; 1997. 36. World Health Organization Collaborating Center; Malmo University. Oral Health Database. Oral Health Country/Area Profile Project. www.mah.se/capp/. Accessed Nov. 2, 2012. 37. Bagramian RA, Garcia-Godoy F, Volpe AR. The global increase in dental caries: a pending public health crisis. Am J Dent 2009; 22(1):3-8. 38. New Zealand, Public Health Advisory Committee; New Zealand, National Advisory Committee on Health and Disability. Improving Child Oral Health and Reducing Child Oral Health Inequalities: Report to the Minister of Health from the Public Health Advisory Committee. Wellington, New Zealand: National Advisory Committee on Health and Disability (National Health Committee); 2003. 39. Jamieson LM, Armfield JM, Roberts-Thomson KF. Dental caries trends among indigenous and non-indigenous Australian children. Community Dent Health 2007;24(4):238-246. 40. Armfield JM. Socioeconomic inequalities in child oral health: a comparison of discrete and composite area-based measures. J Public Health Dent 2007;67(2):119-125. 41. Parker EJ, Jamieson LM. Oral health comparisons between children attending an Aboriginal health service and a Government school dental service in a regional location. Rural Remote Health 2007;7(2):625. 42. Harris RP, Helfand M, Woolf SH, et al; Methods Work Group, Third US Preventive Services Task Force. Current methods of the U.S. Preventive Services Task Force: a review of the process. Am J Prev Med 2001;20(3 suppl):21-35. 43. Moher D, Hopewell S, Schultz KF, et al. CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials (published online ahead of print March 24, 2010) (published correction appears in BMJ 2011;343). BMJ 2010; 340:c869. doi:10.1136/bmj.c869. 44. Schultz KF, Altman DG, Moher D; CONSORT Group. CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials (published online ahead of print March 24, 2010). BMJ 2010;340:c332. doi:10.1136/bmj.c332. 45. von Elm E, Altman DG, Egger M, et al; STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol 2008;61(4):344-349.

JADA 144(1)

http://jada.ada.org

Copyright © 2013 American Dental Association. All rights reserved.

January 2013 91