ABSTRACT
Objective
This research examines the extent of clinical variation across the NSW public dental service, the largest in Australia. Findings may assist policy makers in reducing variation of care and inequity towards value‐based oral healthcare.
Methods
Four years of demographic and treatment data, for 741,450 patients between 1 July 2019 and 30 June 2023, were extracted from the Electronic Oral Health Record System and analysed. Sixteen common dental treatment types provided by NSW Local Health Districts (LHDs) for adults and children were analysed relative to all treated patients in terms of clinical variation. Adult‐only treatment types included posterior root canal treatment, fixed crowns, occlusal splints and metal‐based partial dentures, removal of calculus, as well as full dentures and acrylic partial dentures. Also included, were simple fillings and simple extractions for both adults and children, as well as preformed crowns, pulpotomy, sport mouthguards, treatment under nitrous oxide gas sedation, fissure sealing and fluoride application for children.
Results
Of the 16 total treatment types investigated, eight showed significant variations ranging between 43−961 fold for adults and 17−434 fold for children. In contrast, eight treatments showed far less variation ranging between 1.5 and 2.8 fold.
Conclusion
This research identified significant variations in general dental adult and child treatments provided across NSW LHDs which cannot be attributed or explained demographically. The presence of unwarranted clinical variation would suggest disproportionate and inequitable care delivery across NSW public dental services. Addressing unwarranted clinical variation will likely promote fairer and more equitable provision of public oral health with enhanced patient outcomes.
Keywords: clinical variation, dental services, equity, evidence‐based care, patient‐centred care, value‐based care
Summary.
This study investigates the extent of clinical variation in dental treatments across New South Wales' public dental services, the largest such system in Australia.
The researchers analysed 4 years of demographic and treatment data from the Electronic Oral Health Record System to identify unwarranted clinical variations.
From these findings, clinicians and policy makers can highlight potential inequities in care delivery and underscore the need for a value‐based approach to oral healthcare policy and planning.
This is the first study of its kind that has explored clinical variation across a large public dental service in Australia.
1. Introduction
Unwarranted clinical variation, also known as system‐related clinical variation, refers to variation in the level, scope or type of care provided to a patient which is unexplained by differences in patient's illness or treatment preferences [1]. Unwarranted clinical variation is entirely driven by the health system and largely misaligned with the current evidence base [2]. Exploring the extent of clinical variation across the NSW public oral health system is an important first step towards providing appropriate, evidence based and efficient care. The authors of these papers were tasked by the New South Wales Ministry of Health to lead and implement the Value‐based Oral Health Framework from October 2022 to December 2024.
NSW public dental services are delivered across 15 Local Health Districts (LHDs) and two Speciality Networks (SNs) by approximately 600 dental and oral health practitioners. As at October 2024, there were 197 facilities state‐wide comprising 171 fixed facilities and 26 mobile facilities across the NSW public dental services. Of these, 12 LHDs have both mobile and fixed dental clinics.
Public dental care is delivered in NSW across diverse settings including dental clinics located within public hospital campuses, dental clinics attached to community health centres, standalone dental clinics, mobile clinics or large oral health centres and dental hospitals. Several public dental services provide clinical placements for dental students.
To access NSW public dental services, patient must be a NSW resident and either a child under 18 years old or an adult holding a Healthcare Card, Pensioner Concession Card or Commonwealth Seniors Health Card. Patients can seek care with their local LHD by contacting a centralised contact centre phone number [3].
There is high demand for public dental services with some access limitations and sometimes extensive waiting times [4]. Some 268,655 adults and 68,288 children were triaged for dental care from 1 July 2023 to 30 June 2024, with 231,258 (69%) adults and children requiring urgent dental care. Additionally, 178,127 (53%) adults and children triaged resided in rural/regional areas, compared with 150,279 (45%) adults and children from metropolitan areas.
Publicly funded dental care provided to eligible patients across NSW is delivered through two main pathways: in‐house care at NSW public dental clinics and privately delivered dental care outsourced to external dental providers through the Oral Health Fee For Service Scheme (OHFFSS) vouchers [5].
NSW public dental care can be broadly summarised as consisting of episodic care for relief of pain and management of dental emergencies, comprehensive general dental care for patients on the public dental waiting lists [6] and specialist dental care for patients referred for specialist treatment. In addition, several LHDs provide school‐based dental screening and preventive care for primary school children.
Generally, there are no prescribed restrictions on the scope of clinical services provided to public dental patients, particularly when treated in‐house. The general consensus is that public patients should receive the most appropriate, readily available and evidence‐based dental treatment as determined by clinical needs. Typically, the complexity of dental treatments provided to public patients can be divided into three broad categories:
Basic dental care which includes diagnostic, preventative and common interventions like dental fillings and extractions, teeth cleaning, gum treatments, root canal treatment for single rooted teeth and acrylic dentures. These services constitute approximately 90% of the general dental services provided across the NSW public dental system.
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Mid‐range dental care for adults includes fixed prosthodontics (crowns and bridges), metal‐based partial dentures, occlusal splints and root canal treatment for posterior, multirooted teeth.
Child mid‐range treatments include preformed stainless steel crowns, pulp treatment for primary teeth (pulpotomy), treatment under relative analgesia (nitrous oxide gas) and sports mouthguards.
Specialised dental care, which is usually provided by dental specialists or suitably experienced generalists. This group includes, among others, dental implants, full mouth oral rehabilitation, complex periodontal treatment, orthodontic treatment and complex oral surgical procedures.
It should be noted that both basic and mid‐range groups of dental treatments can be provided by the general dental practitioners and dental students in clinical placements across NSW public dental services.
Given the considerable diversity and large geographic scale of the NSW oral health system, it is expected to encounter system‐ or practice‐related clinical variations.
An integral part of value‐based healthcare is delivering evidence‐based, equitable and effective care to all patients which is based on their clinical condition [7]. The transition of dental healthcare to value‐based care is underpinned by improving the oral health outcomes of patients while minimising the cost to achieve those improvements [8]. It is known that oral diseases can cause pain, impact eating, speech, self‐esteem, participation in everyday activities and thus a person's overall quality of life [9]. Key attributes of an ideal oral health system should include being evidence‐based, equitable and should provide every person in the community with equal access to appropriate dental care [10].
Variation of healthcare and treatment is both warranted and desirable when it is driven by the underlying need for care [11]. Such variation is considered warranted if different treatment modalities achieve equivalent patient outcomes. This is demonstrated where there are several acceptable, evidence‐based treatment modalities and there are no specific guidelines for the delivery of a particular singular modality or when evidence‐based guidelines allow for multiple approaches. It is appropriate in such situations for clinicians to capitalise on their particular skill sets as well as available resources to select the most appropriate treatment modality [12]. However, within public health organisations with finite resources, further considerations should be given to the overall value of certain treatment modalities that require significant resources.
Conversely, unwarranted clinical variations can lead to compromised patient outcomes, diminished patient experiences and inefficient use of healthcare resources [13]. Unwarranted clinical variation can be driven by three main factors: clinician underutilising evidence‐based interventions, differences in clinician and patient treatment preferences or supply‐sensitive care where the availability of certain treatment resources influences treatment decisions rather than the clinical presentations and needs being the primary determinants [14].
Unwarranted clinical variations have been explored and analysed based on three main criteria:
Perspective approach, which is the geographical or provider‐based analysis of the distribution of unwarranted clinical variation.
The scope of the variation, distinguishing between absolute unwarranted clinical variation which deviates from established standards of care, and relative clinical variation, where two or more relatively valid approaches exist to meet the patient needs.
Clinical variation causation analysis focusing on either process, outcome or resources utilisation.
Measuring clinical variation is a complex process because it must fundamentally aim to distinguish between system driven and clinician driven variations. The analysis of this context does not diminish the concerns about unwarranted clinical variation, rather it can identify a roadmap to address the unwarranted clinical variation because in situations where organisational context is at the root of variation, it can be considered to be reasonable however may still be unacceptable and require redress [12].
This study is descriptive in nature with the main objective to examine the presence and extent of dental clinical variations among NSW Local Health Districts. This study does not aim to examine or provide a hypothesis about the causes of clinical variations across the NSW public dental services.
2. Methods
2.1. Study Design and Data Source
A review of unwarranted clinical variation by the Health Quality and Safety Commission of New Zealand recommended focusing on the appropriateness of care, measured directly by care process measures such as the volume or quality of care provided, or indirectly through outcome measures [15]. This study measured unwarranted clinical variation in dentistry by examining the differences in the volume of treatment provided among dental services, expressed as rates of delivering a certain procedure per set number of patients [16]. Retrospective data was obtained using a state‐based electronic public dental record system, Titanium and sourced via the NSW Health Centre for Oral Health Strategy, a branch of the NSW Ministry of Health (MoH). The analysis investigated differences between LHDs in the provision of basic and mid‐range dental procedures.
The targeted comparative analysis compared volumes of 16 common, mid‐range, types of treatment consisting of eight pertaining to adults (1–8) and eight to children (9–16) (Table 1).
TABLE 1.
List of adult and child treatments for analysis.
| Adult treatments | Child treatments |
|---|---|
| 1. Fixed dental prosthodontics (crowns) | 9. Mouthguards for sports |
| 2. Removable partial dentures with metal framework | 10. Treatment under relative analgesia (nitrous oxide gas inhalation) |
| 3. Root canal treatment for multirooted teeth (mostly posterior teeth) | 11. Preformed crowns |
| 4. Occlusal splint | 12. Primary teeth pulp therapy (pulpotomy) |
| 5. Removal of calculus | 13. Simple extraction |
| 6. Simple extraction | 14. Simple filling |
| 7. Simple filling | 15. Fissure sealing |
| 8. Standard dentures (full dentures and acrylic partial dentures) | 16. Fluoride application |
A snapshot of previously recorded data was taken on 22 November 2023. Service codes representing individual treatment modalities were extracted for each LHD and tabulated. The analysis utilised folds of variation among LHDs to express the level of clinical variation. Finally, frequencies and mean values of demographic data and treatment types across 14 LHDs were calculated. Statistical significance was set at p < 0.05.
The above were further divided into two additional groupings with corresponding Australian Dental Association item numbers [17] and was based on prior knowledge from the authors surrounding patterns of public oral health delivery in NSW as presented in Table 2
Lower frequency, high variance group (LFHV): this group of treatment modalities included eight mid‐range treatments for adults and children, which are provided at lower frequency and with high variation across the NSW public dental services and includes posterior root canal treatment, fixed crowns, occlusal splints and metal‐based partial dentures for adults. It includes preformed crowns, pulpotomy, sport mouthguards and treatment under nitrous oxide gas sedation for children.
Higher frequency, low variance group (HFLV): this group of treatment modalities included some of the most commonly provided treatment modalities across NSW public dental services. Eight treatment types for adults and children were selected. The analysis of this group of treatments serves as a control and demonstrates the degree of variation in offering the treatments in the LFHV group despite the common patient cohorts. For adults, HFLV treatments include simple extractions, simple fillings, removal of calculus and standard dentures, which include full dentures and acrylic partial dentures. Likewise, it includes simple extractions and fillings, fissure sealings and fluoride applications for children.
TABLE 2.
Description of item numbers (ADA dental treatment service codes) selected for analysis.
| Target age | Grouping | Item number | ADA definition |
|---|---|---|---|
| Adult LFHV | Posterior teeth RCT | 418 | Root canal obturation—each additional canal |
| Crowns | 613 | Full crown—ceramic—indirect | |
| 615 | Full crown—veneered—indirect | ||
| 618 | Full crown—metallic—indirect | ||
| Metal frame P/D | 727 | Partial maxillary denture—custom fabricated metal framework | |
| 728 | Partial mandibular denture—custom fabricated metal framework | ||
| Occlusal splint | 965 | Occlusal appliance | |
| Adult HFLV | Removal of calculus | 114 | Removal of calculus—first appointment |
| Simple extraction adult | 311 | Removal of a tooth or part(s) thereof | |
| Simple fillings adult | 521 | Adhesive restoration—one surface—anterior tooth—direct | |
| 531 | Adhesive restoration—one surface—posterior tooth—direct | ||
| Standard dentures | 711 | Complete maxillary denture | |
| 712 | Complete mandibular denture | ||
| 719 | Complete maxillary and mandibular dentures | ||
| 721 | Partial maxillary denture—resin base | ||
| 722 | Partial mandibular denture—resin base | ||
| Child LFHV | Mouthguard | 151 | Provision of a mouthguard—indirect |
| 153 | Bi‐maxillary mouthguard—indirect | ||
| Pulpotomy | 414 | Pulpotomy | |
| Relative analgesia | 943 | Relative analgesia—inhalation of nitrous oxide and oxygen mixture—per 30 min or part thereof | |
| Preformed and St crowns | 576 a | Stainless steel crowns | |
| 586 | Preformed full crown—metallic—significant tooth preparation | ||
| 587 | Preformed full crown—metallic—minimal tooth preparation | ||
| 588 | Preformed full crown—tooth coloured | ||
| Child HFLV | Simple extraction child | 311 | Removal of a tooth or part(s) thereof |
| Simple fillings child | 521 | Adhesive restoration—one surface—anterior tooth—direct | |
| 531 | Adhesive restoration—one surface—posterior tooth—direct | ||
| Fissure sealing | 161 | Fissure and/or tooth surface sealing—per tooth | |
| Fluoride application | 121 | Topical application of remineralisation agents, one treatment | |
| 123 | Application of a cariostatic agent—per tooth |
Item number was retired in 2021.
2.2. Study Population
The study population included adults (aged ≥ 18 years) and children (aged < 18 years) who received dental services at NSW Health public dental services between 1 July 2019 and 30 June 2023 and received treatment either in‐house or via a claimed Oral Health Fee For Service Scheme (OHFFSS) voucher. Services provided under general anaesthesia were excluded.
The analysis was restricted to 14 LHDs, excluding one remote Local Health District that did not have a regular dental service during most of the study period. Similarly, services delivering limited scopes of treatments such as Speciality Networks, Justice Health and Aboriginal Medical Services were excluded, as were services delivered through the Primary School Mobile Dental Program.
Patients who fell into both the adult and child age groups during the analysis period were reported in both groups. Patient's demographic information including age and sex as well as adult treatment pathways (in house or OHFFSS voucher) was analysed.
2.3. Statistical Analysis
Data analysis was carried out using R version 4.3.1. Numbers and percentages were calculated for categorical variables while for continuous variables, the median and interquartile range (IQR) were calculated. The chi‐square test of independence and Wilcoxon rank sum test were used to determine differences between demographic characteristics among LHDs. Clinical variation was measured by identifying the percentage of patients receiving the treatment compared to the whole patient population. Clinical variations were expressed as folds of difference between the highest and the lowest rates of delivering particular treatment in the various LHDs.
3. Results
3.1. Demographic Characteristics
A total of 741,450 patients accessed NSW public dental services between 1 July 2019 and 30 June 2023, including 507,289 adults aged ≥ 18 years and 237,718 children. The median age of adult patients accessing the services ranged between 54 and 66 years old. Female adult patients were presenting more often than adult male patients across the 14 LHDs, with a range between 54% and 59%. The percentage of adult patients identifying as Aboriginal or Torres Strait Islanders varied considerably among the 14 LHDs, with a range between 2.5% at one metropolitan LHD and 23% at another rural LHD. Additionally, LHDs relying on OHFFS vouchers rather than in‐house treatment ranged from a low of 1% to a high of 41%. Significance was recorded among each of the demographic characteristics (Table 3). The demographic characteristics for children presenting across the 14 LHDs showed less variation in comparison to the adult patients yet similar significance. The median age of children seeking public dental care across the 14 LHDs ranged between 7 and 9 years of age. The percentage of female to male children ranged between 46% and 51%. Additionally, the percentage of children identifying as Aboriginal or Torres Strait Islanders demonstrated large differences across the LHDs, similar to adult patients, with a range between 5.4% and 31% (Table 4).
TABLE 3.
Adult patients' characteristics at the time of first visit between 1 July 2019 and 31 June 2023 by LHD.
| Characteristic | LHD1 | LHD2 | LHD3 | LHD4 | LHD5 | LHD6 | LHD7 | LHD8 | LHD9 | LHD10 | LHD11 | LHD12 | LHD13 | LHD14 | χ 2 | p |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age, median (IQR) | 58 (38, 72) | 56 (36, 71) | 59 (40, 72) | 57 (37, 71) | 58 (37, 71) | 54 (35, 70) | 58 (40, 70) | 66 (48, 75) | 64 (45, 75) | 61 (41, 72) | 56 (39, 69) | 61 (43, 74) | 56 (36, 71) | 54 (36, 69) | < 0.001 | |
| Aboriginal and/or Torres Strait Islanders | ||||||||||||||||
| Yes | 8.8% | 15% | 7.1% | 9.3% | 12% | 8.6% | 9.4% | 2.5% | 5.5% | 9.0% | 3.2% | 5.7% | 23% | 6.2% | 16,269 | < 0.001 |
| Sex | ||||||||||||||||
| Female | 57% | 56% | 57% | 58% | 54% | 59% | 53% | 54% | 56% | 56% | 57% | 53% | 57% | 56% | 519.57 | |
| Male | 43% | 44% | 43% | 42% | 46% | 41% | 47% | 46% | 44% | 44% | 43% | 47% | 43% | 44% | ||
| Treatment pathway | ||||||||||||||||
| In house | 88% | 69% | 67% | 67% | 79% | 97% | 67% | 96% | 65% | 69% | 94% | 84% | 59% | 99% | 59,351 | < 0.001 |
| Voucher | 12% | 31% | 33% | 33% | 21% | 2.6% | 33% | 3.6% | 35% | 31% | 6.1% | 16% | 41% | 10% | ||
TABLE 4.
Child patients' characteristics at the time of first visit between 1 July 2019 and 31 June 2023 by LHD.
| Characteristic | LHD1 | LHD2 | LHD3 | LHD4 | LHD5 | LHD6 | LHD7 | LHD8 | LHD9 | LHD10 | LHD11 | LHD12 | LHD13 | LHD14 | χ 2 | p |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age, median (IQR) | 8 (6, 11) | 9 (5, 12) | 8 (5, 12) | 8 (5, 12) | 8 (5, 11) | 8 (6, 11) | 8 (5, 11) | 9 (5, 11) | 8 (5, 12) | 8 (5, 12) | 9 (6, 12) | 9 (5, 13) | 7 (4, 11) | 7 (5, 11) | < 0.001 | |
| Aboriginal and/or Torres Strait Islanders | ||||||||||||||||
| Yes | 16% | 27% | 18% | 15% | 23% | 13% | 15% | 6.7% | 7.3% | 15% | 5.4% | 7.5% | 31% | 8.4% | 10,815 | < 0.001 |
| Sex | ||||||||||||||||
| Female | 47% | 50% | 50% | 50% | 51% | 49% | 50% | 48% | 48% | 49% | 49% | 48% | 50% | 46% | 138.00 | < 0.001 |
| Male | 53% | 50% | 50% | 50% | 49% | 51% | 50% | 52% | 52% | 51% | 51% | 52% | 50% | 54% | ||
3.2. Clinical Variation
The analysis demonstrated a high level of clinical variations among the 14 NSW LHDs in performing LFHV dental treatments compared to minimal variations in delivering the HFLV dental treatment for both adults (Figures 1 and 2) and children (Figures 3 and 4).
FIGURE 1.
Frequency of adult treatment modality by LHD, high variation group, 1 July 2019 to 31 June 2023.
FIGURE 2.
Frequency of adult treatment modality by LHD, low variation group, 1 July 2019 to 31 June 2023.
FIGURE 3.
Frequency of child treatment modality by LHD, high variation group, 1 July 2019 to 31 June 2023.
FIGURE 4.
Frequency of child treatment modality by LHD, low variation group, 1 July 2019 to 31 June 2023.
Tables 5 and 6 detail the percentage of patients receiving each treatment modality within both LFHV and HFLV groupings among all patients presenting at each LHD. They also provide the maximum folds of variation between the LHDs with the highest and lowest rates of delivery for each modality, excluding LHDs which did not deliver the particular treatment over the study period.
TABLE 5.
Percentage of adult and child patients' receiving LFHV per LHD.
| LHD | Adult | Child | ||||||
|---|---|---|---|---|---|---|---|---|
| Crowns | Metal RPD | Posterior RCT | Occlusal splint | Preformed crowns | Pulpotomy | Mouthguards | NO2 sedation | |
| LHD1 | 0.003% | 0.535% | 0.010% | 0.019% | 12.600% | 0.207% | 0.021% | 6.290% |
| LHD2 | 0.074% | 0.916% | 0.246% | 0.158% | 8.509% | 2.025% | 0.375% | 1.402% |
| LHD3 | 0.003% | 0.599% | 0.151% | 0.325% | 0.892% | 2.729% | 0.011% | 0.064% |
| LHD4 | 0.004% | 0.762% | 0.106% | 0.358% | 3.117% | 0.362% | 0.269% | 2.699% |
| LHD5 | 0.000% | 0.180% | 0.100% | 0.273% | 1.629% | 1.009% | 0.049% | 2.164% |
| LHD6 | 2.741% | 2.785% | 1.921% | 1.369% | 9.720% | 3.598% | 0.478% | 5.900% |
| LHD7 | 0.172% | 0.287% | 0.911% | 0.643% | 6.640% | 1.017% | 0.038% | 2.025% |
| LHD8 | 0.005% | 0.282% | 0.810% | 0.005% | 3.687% | 0.726% | 0.016% | 0.916% |
| LHD9 | 0.016% | 1.064% | 0.123% | 0.273% | 1.018% | 2.196% | 0.868% | 0.018% |
| LHD10 | 0.005% | 1.282% | 0.225% | 0.022% | 6.452% | 0.946% | 0.000% | 0.543% |
| LHD11 | 0.038% | 1.548% | 0.324% | 0.068% | 0.493% | 1.930% | 0.043% | 1.764% |
| LHD12 | 1.055% | 7.692% | 1.659% | 1.222% | 4.297% | 1.485% | 0.480% | 7.678% |
| LHD13 | 0.044% | 0.395% | 0.199% | 0.186% | 4.678% | 1.276% | 0.000% | 3.302% |
| LHD14 | 0.996% | 1.267% | 1.377% | 1.239% | 5.949% | 1.859% | 0.177% | 5.891% |
| Max folds | 961 | 43 | 199 | 296 | 26 | 17 | 79 | 434 |
TABLE 6.
Percentage of adult and child patients' receiving HFLV treatments per LHD.
| LHD | Adult | Child | ||||||
|---|---|---|---|---|---|---|---|---|
| Extractions | Fillings | Calculus removal | Dentures | Extractions | Fillings | Fissure sealing | Fluoride application | |
| LHD1 | 42.7% | 26.0% | 32.4% | 15.8% | 16.9% | 19.4% | 36.7% | 58.0% |
| LHD2 | 42.3% | 26.8% | 34.0% | 17.8% | 18.9% | 23.1% | 18.0% | 58.7% |
| LHD3 | 40.5% | 33.2% | 41.1% | 23.9% | 16.5% | 23.1% | 18.3% | 33.0% |
| LHD4 | 41.7% | 21.5% | 28.6% | 19.1% | 14.9% | 22.5% | 21.7% | 61.9% |
| LHD5 | 36.8% | 27.6% | 35.4% | 21.2% | 13.6% | 18.9% | 15.0% | 55.4% |
| LHD6 | 38.6% | 29.4% | 38.4% | 13.4% | 16.0% | 15.9% | 27.7% | 56.2% |
| LHD7 | 37.8% | 31.4% | 37.0% | 17.8% | 13.4% | 14.3% | 26.2% | 47.2% |
| LHD8 | 35.3% | 30.6% | 46.4% | 20.5% | 11.6% | 13.4% | 21.8% | 52.0% |
| LHD9 | 31.5% | 32.0% | 40.3% | 21.9% | 10.5% | 16.4% | 19.1% | 67.0% |
| LHD10 | 40.5% | 27.6% | 33.5% | 19.8% | 15.0% | 19.9% | 20.8% | 57.4% |
| LHD11 | 39.0% | 26.7% | 36.6% | 18.4% | 16.2% | 20.6% | 17.6% | 45.2% |
| LHD12 | 29.8% | 24.2% | 38.7% | 12.4% | 10.0% | 10.2% | 13.3% | 47.8% |
| LHD13 | 44.9% | 22.0% | 33.0% | 18.2% | 19.0% | 18.0% | 22.4% | 55.0% |
| LHD14 | 34.9% | 20.0% | 31.2% | 11.7% | 12.1% | 9.6% | 13.4% | 30.4% |
| Max folds | 1.5 | 1.7 | 1.6 | 2.1 | 1.8 | 2.4 | 2.8 | 2.2 |
4. Discussion
Value‐based oral healthcare provides a foundation to deliver better oral healthcare across NSW [18]. This study analysed public dental services delivery across NSW from 1 July 2019 to 30 June 2023, identifying areas of significant clinical variation in several treatment modalities among the state's public dental services. In particular, the study targeted the clinical variations among LHDs in delivering eight lower frequency, high variance (LFHV) treatment modalities.
The rationale for selecting treatments within the LFHV group includes that these procedures constitute standard treatments that can be typically delivered by a general dental practitioner or even by a senior dental student and they do not normally require the input of dental specialists. This is important, in terms of variation validity, since not all Local Health Districts across NSW have access to dental specialists. Additionally, the selected treatments are established and recognised evidence‐based, mainstream treatment modalities, with decades of global clinical use. Furthermore, these are dental interventions known to have a measurable impact on the patient's overall oral health outcomes and therefore have a considerable impact on their Oral Health Related Quality of Life (OHRQoL). Finally, the selected treatments typically have positive cost benefit ratios. There is a considerable body of evidence confirming that when these treatment modalities are provided in clinically appropriate instances, they can reduce unplanned re‐presentation, retreatment and detrimental impact to oral health tissues and function, compared to other less expensive alternatives.
Another eight higher frequency, low variance (HFLV) treatment modalities were also examined, four for adults and four for children. The analysis of this group of treatments serves as a control and demonstrates the degree of variation in offering the treatments in the target group of treatment modalities despite the common patient cohorts receiving all the treatments.
The LFHV treatments were offered to a smaller number of patients across all the LHDs. The total number of adult patients receiving the four LFHV treatment modalities in NSW was 13,695 compared to 344,053 adult patients receiving the four HFLV treatment modalities. Similarly, the total number of children receiving the four LFHV treatment modalities in NSW was 14,337 compared to a total of 126,652 children receiving the four HFLV treatment modalities. The smaller number of adult and child patients receiving the LFHV dental treatment is expected because these treatments are provided less frequently due to their specific clinical requirements.
Differences in treatment in terms of folds of variation is a methodology commonly used in analysing clinical variation in care delivery [19]. Analysing and comparing the rate of service delivery in this fashion reduced the need to account for the difference in LHD sizes, or the number of dental chairs/clinicians and their individual case load at each LHD. The analysis identified that the delivery of the selected LFHV treatment was largely inconsistent across the 14 LHDs. The analysis demonstrated that some treatment modalities were provided hundreds of folds more in some LHDs compared to others (Table 5) and that in few LHDs, some treatment modalities were not provided at all or were provided only to one patient during the 4 years of analysis (Figures 1 and 3). For example, for the 4 years of analysis, the proportion of adult patients receiving crowns in the highest scoring LHD was 961‐fold more than the combined average percentage of the lowest 5 LHDs offering crowns (2.74% vs. 0.003%) (Table 5). For root canal treatment for teeth with multiple roots (mainly posterior teeth), the highest LHD was 199‐fold more than the LHDs that rarely offer this treatment (1.921% vs. 0.01%). Metal‐based partial dentures were provided in one LHD 43‐fold more than the lowest LHD (9.692% vs. 0.180%). Occlusal splints were provided in one LHD 296‐fold more than the lowest LHD (1.369% vs. 0.005%) (Table 5). Inversely, there was, at maximum, 2.1‐fold of variation between the highest and the lowest LHDs in NSW for the adult high frequency, low variation (HFLV) group of treatments which includes simple extraction, acrylic dentures, simple fillings or removal of calculus (Table 6).
The analysis equally demonstrated a similar situation for children indicating significant variation between the highest and lowest LHDs for the proportion of children receiving the LFHV treatments as follows: 434‐fold for the nitrous oxide sedation (7.678% vs. 0.018%), 79‐fold for the provision of mouthguards (0.868% vs. 0.011%), 26‐fold for the provision of preformed stainless steel crowns (12.600% vs. 0.493%) and 17‐fold for the provision of pulpotomy (3.598% vs. 0.207%) (Table 5). The difference in the proportion of children receiving the HFLV treatment group between the highest and the lowest LHDs was at most 2.8‐fold (Table 6).
While most studies and publications examining clinical variation examine the delivery of care per geographical area, by analysing the patients' place of residence [20], this study is analysing the care based on the location of treatment, that is, the Local Health District where the patients received their care because eligible public dental patients within NSW can only receive general dental care at their Local Health Districts. Studies examining variation of clinical care often identify oversupply of treatment or the provision of low‐value care with minimal support of clinical evidence [19]. Our study, on the other hand, identifies clinical variation across several treatments predominantly expressed as under‐delivery of care which in some instances manifested by the complete absence of the treatment option at a certain service location.
The wide variation across the 14 LHDs in the high variation treatment modalities which is not matched in the low variation treatment modalities suggests that these discrepancies are most likely a system‐related variation. System‐related variation is unwarranted clinical variation because it is not based on the patient's clinical needs; rather, it is caused by restraints or barriers within the health system [12]. This variation in clinical care is caused by the inherent limitations and constrained capacity across the entire NSW public dental services; however, it is evident that these limitations are not present to the same level across different LHDs. The constrained capacity may be the result of limited infrastructure, reduced staffing levels, inability to attract or retain experienced clinicians, increased demand for emergency dental care, reduced access to technical support, reduced access to advanced technologies like CAD/CAM and digital dentistry or the absence of clear clinical guidelines [21]. All these barriers and restraining factors are often beyond the control of the treating clinicians [22]. They may contribute to the inability of several LHDs to regularly offer the full scope of general dental treatment for their adult and child patients.
The Australian Commission on Safety and Quality in Health Care states that unwarranted variation raises questions about quality, equity and efficiency in healthcare [20]. It may mean some people have less access to healthcare compared with others. It may also suggest that factors other than patients' needs or preferences are driving treatment decisions. It may indicate that some people are having unnecessary and potentially harmful tests or treatments, while others are missing out on necessary interventions. It is important to appreciate the impact that system‐related clinical variations can have on Oral Health Related Quality of Life (OHRQoL) for the public dental patients [23]. From the established evidence, patients, for example, who were clinically suitable to receive metal‐based partial dentures and instead were provided with an acrylic substitute, can be at increased risk of detrimental impact on their teeth and gums due to the lack of important characteristic design features inherent in acrylic partial dentures [24, 25, 26, 27]. Similarly, patients with posterior teeth assessed with reasonable prognosis and clinically indicated for root canal treatment but were instead extracted can be at increased risk of partial edentulism, compromised mastication and the potential need to use avoidable dentures [28, 29, 30]. Adult patients who were not offered an appropriate fixed prosthodontic in the form of dental crowns are likely to require additional restorative treatment or suffer addtional damage to their teeth [31, 32, 33]. Children playing sports who are not provided with mouthguards are at higher risk of dental trauma, which can lead to protracted and complex dental treatment to manage damaged teeth that may have been preventable [34, 35]. Children with teeth indicated for pulpotomy but were instead prematurely extracted can be at higher risk of crowding and malocclusion and have a higher propensity for needing future expensive and complicated orthodontic treatment [36, 37]. Additionally, children who did not receive preformed stainless steel crowns as opposed to large fillings can be at increased risk of recurrent decay and premature loss of their primary teeth [38, 39, 40]. Finally, young children who do not have access to treatment under nitrous oxide gas inhalation sedation may be subjected to more stressful dental management, or necessitating avoidable referral for more resource‐intensive, delayed and potentially riskier treatment under general anaesthesia [41, 42, 43].
The benefit of reducing unwarranted clinical variations is not limited to improving the patients' quality of life and providing equitable patient‐centred care. Dental clinicians working across the public dental services often have poorer career progression and job satisfaction compared to their counterparts working across the private sector; this may be partially due to the reduced or limited scope of clinical services offered across the public dental services [44]. A limited scope of clinical practice has been proven to negatively impact the professional satisfaction of both dentists [45] and oral health therapists [46]. On the other hand, practising a broader scope of clinical dentistry improves clinical confidence, which in turn improves clinician satisfaction and staff retention [47]. Therefore, broadening the scope of services across NSW public dental services could potentially have a positive impact on the clinicians' experience, engagement and skills, thereby further contributing to the quadruple aims of value‐based healthcare [48].
With the results demonstrated in this study, NSW Health was able to develop a roadmap for reducing system‐related clinical vacation. The roadmap relies on developing state‐wide, evidence based and contextualised models of care [49], which take into account the current clinical evidence [50], the empirical data from NSW public dental services, along with consumers and clinicians views. These clinical models of care will guide the dental clinicians across the system to deliver consistent clinical care regardless of the patient's location [51]. The first working group to develop a state‐wide model of care for the provision of dentures was established in late 2024, with additional working groups planned to address other areas of clinical practices with the greatest levels of clinical variation.
Additionally, the Centre for Oral Health Strategy has been developing a capacity building education programme to upskill and clinically develop public sector dental clinicians to confidently deliver more complex dental procedures [52]. The programme is also supported by substantive capital investment in comprehensive digital dentistry equipment. One example is the acquisition and placement of multiple CAD/CAM complete systems, intraoral scanners and 3D printers for the provision of chairside, single visit, fixed prosthodontics, dental prosthetics and occlusal splints. This equipment has been preferentially located within rural clinics across NSW and will help address some treatment service gaps and improve service equity across the NSW public dental services.
There were several challenges and limitations identified in this study, including that the data analysis was conducted based on where the care was provided rather than where the patients live because data can only be extracted for patients' recorded residence at a particular time point, rather than the time of treatment. However, given the NSW public dental services mandate that patients receive general dental treatment at their respective LHDs, the authors believe that the data presented in this study accurately reflects the variation of clinical care at geographical level across NSW. Additionally, not all LHDs implemented the electonic dental record ‘Titanium’ by June 2018. One LHD migrated to Titanium in September 2018. This small period without ‘Titanium’ in one LHD is unlikely to impact the results of the study since the data analysis is predominantly based on the proportionality of patients receiving treatment rather than the comparison of the total numerical values. Furthermore, the impact of COVID‐19 on public health service was greatly manifested across 2 years of the analysis period between 2020 and 2022. However, the authors, in addition to analysing the combined 4‐years data, also analysed the data for each year individually, which consistently demonstrated the same level of clinical variation across the 14 LHDs.
5. Conclusion
Addressing unwarranted and system‐related clinical variation is an essential goal in helping establish a framework towards value‐based oral healthcare.
It is essential in addressing unwarranted clinical variation to examine and establish the extent of this variation and to propose pathways to reduce system‐related variations.
This study is the first to examine clinical variation within the NSW public dental services. It assists by providing a foundation for further analysis and policy development to help examine and potentially reduce variation across the public oral health services. Initiating this type of analysis has been foundational in assisting NSW public oral health towards addressing dental clinical variations across the state of NSW, Australia.
Ethics Statement
This study relied on pre‐aggregated and non‐identifiable data collected by the NSW MoH and was granted ethical review exemption from the Western Sydney Local Health District Human Research Ethics Office.
Consent
This paper analyses the delivery of care at service‐wide level with no individual or personal information accessed.
Conflicts of Interest
The authors declare they are both employees of NSW Health.
Acknowledgements
The authors acknowledge and thank Graeme Liston, the Executive Director for the Centre for Oral Health Strategy, NSW, Ministry of Health for initiating and supporting this project. Sandy Ma from the Centre of Epidemiology and Evidence for assistance with the statistical analysis of this study as well as the WSLHD hospital librarians Bernadette Nicholl and Linda Mulheron for collating the literature evidence base. Open access publishing facilitated by Western Sydney University, as part of the Wiley ‐ Western Sydney University agreement via the Council of Australian University Librarians.
Data Availability Statement
The data that support the findings of this study are available from NSW Health. Restrictions apply to the availability of this data. Data is available from the author(s) with the permission of NSW Health.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data that support the findings of this study are available from NSW Health. Restrictions apply to the availability of this data. Data is available from the author(s) with the permission of NSW Health.