A national audit of Australian dental practice distribution: do all Australians get a fair deal?

Abstract

Australia is the sixth biggest (by area) country in the world, having a total area of about 7.5 million km² (3 million square miles). This study located every dental practice in the country (private and public) and mapped these practices against population. The total population of Australia (21.5 million) is distributed across 8,529 suburbs. On average about one-third of the population from each State lives in suburbs without practices and 46% live in suburbs with one to five dentists. Of those living within the study frameset, 86.6% live within 5 km of a private practice and 84.4% live within 10 km of a government practice. Australia’s dental practices are distributed in a very uneven fashion across its vast area. Three-quarters of suburbs have no dental practice and over one-third of the population live in these suburbs. This research clearly identified that in a vast and uneven socio-geographically distributed country, service planning, if left to market forces, will end with a practice distribution that is fixed by economic drivers of scale and not that of disease burden. A more population health-driven approach to future design and construction of government safety net services is needed to address these disparities.

INTRODUCTION

Australia is the sixth biggest (by area) country in the world, having a total area of about 7.5 million km² (3 million square miles)¹. As a population Australians live predominantly near the coast, with nearly 90% of the 21 million population living in major cities or inner regional areas. This extreme socio-geographic mal-distribution raises specific issues of service access for Australia.

Dentistry in Australia has faced, and continues to face, significant workforce issues, in particular a shortage of practitioners and a grossly distorted distribution². To date much of the research and policy activities in dental workforce planning is based on sampled data of dentist, practice and population³. These sample-based studies are used extensively by government and various think-tanks to promote arguments for and against increased workforce development and the driving of various funding allocation agendas4., 5., which is consistent with what happens in other countries6., 7., 8..

The vast majority of dental care in Australia (greater than 80%) is provided by private dental practices on a fee-for-service basis. A much smaller safety net (for those of low socioeconomic background) is provided through government-supported dental services.

This study is the first in Australian history to attempt to locate every dental practice in the country (private and public) and to map these practices against population. The hypothesis tested in the study is that there is an even density distribution of dental practices across Australia.

METHODS AND MATERIALS

Practice location

The physical address for each dental practice in Australia was collated from a number of open sources, including the Government Gazette and the Registration board website, Web searches and websites of dental services across Australia. These addresses were crossed checked against the Yellow Pages as at August 2012. All addresses were entered into a database and the longitude and latitude of each practice address was obtained using tailor-made software resting on the free access API of a geocoding website (https://developers.google.com/maps/documentation/geocoding/). A randomly selected sample of 1–2% of all geocoded practices was tested against personal knowledge and telephone calls to test the integrity of the data (the confirmatory sample was found to be 95% concordant with the data collected from electronic sources). Ninety-nine per cent of private practices and all of the government practice address could be geocoded and were included in the study sample.

Population data

All population data were obtained from the Australian Census of Population and Housing (2006) and divided by suburbs⁹. These data are freely available through the Internet and are released by the Australian Bureau of Statistics (ABS). Suburbs were chosen as the geographic regions of choice, as the address of each practice also included the suburb, which acted as a cross-check to the geocoding. Also collected from the ABS website were suburb boundary files in shapefile format that matched the commensurate population data files.

All data analysis including the calculation of practice-to-population (PtP) ratios was completed using Excel version 2003 (Microsoft, Redmont, WA, USA). Geographic boundary data for each suburb were integrated to the population, suburb boundaries and dental practice data using arcgis version 10 (ESRI, Redlands CA, USA). All data for analysis were then extracted from the integrated geographically aligned database.

RESULTS

The total population of Australia (21.5 million) is distributed across 8,529 suburbs. Suburbs are of very different sizes and geographic areas and have populations ranging downward from 48,000 people (average about 2,500). A total of 6,998 separate private general dental practices and 390 government dental practices are distributed across these suburbs (Figure 1). The overall PtP ratio is approximately one practice per 3,000 people.

Figure 1.

A map of Australian suburbs (top) and a high-resolution of a major capital city (bottom) overlaid with dental practices (blue, private practices; red, government practices). The suburbs shaded grey have an area greater than 10,000 square kilometres. Note that the centre of Australia (towards the south) has a large region not defined as suburb.

Some suburbs are vast in area (greater than 10,000 square kilometres) and these are predominantly in the interior of Australia. These suburbs cover a total area of 5.5milion km² and have a total residential population of just over 100,000 (Figure 1). Against this background, only suburbs of less that 10,000 km² were included in this study (and the commensurate practices within these postcodes) for analysis. There are 7,169 practices (95% being private practices) within these 8,402 suburbs covering an area of 1.8 million km²with a total population of 21.4 million people and an overall PtP ratio of one practice per 2,985 people.

Within the sample frameset there are a total of 6,446 suburbs that do not contain a dental practice (Table 1). This ranges from 95% of Northern Territory (NT) suburbs to a low of 58% of suburbs in the Australian Capital Territory (ACT) the average being 77% (Table 2). Approximately 20% of suburbs have between one and five practices. Approximately 7.1 million people live in suburbs without a dental practice across Australia, with a high of 2.3 million in New South Wales (NSW). On average, about one-third of the population from each state live in suburbs without practices and 46% live in suburbs with one to five dentists (Table 2).

Table 1.

The number of suburbs with various numbers of dental practices by Australian State

Practices	NSW	VIC	QLD	SA	WA	TAS	NT	ACT	N/Def	Total
Number of dental practices per suburb
0	2,034	1,172	1,394	590	636	372	179	62	7	6,446
1–5	470	285	350	239	187	46	10	39	0	1,626
6–10	63	59	58	14	20	2	1	2	0	219
11–15	22	19	12	1	6	1	0	2	0	63
16+	27	12	3	1	3	1	0	1	0	48
Total	2,616	1,547	1,817	845	852	422	190	106	7	8,402
Proportion of National (Horizontal)
0	31.6%	18.2%	21.6%	9.2%	9.9%	5.8%	2.8%	1.0%	0.1%	100.0%
1–5	28.9%	17.5%	21.5%	14.7%	11.5%	2.8%	0.6%	2.4%	0.0%	100.0%
6–10	28.8%	26.9%	26.5%	6.4%	9.1%	0.9%	0.5%	0.9%	0.0%	100.0%
11–15	34.9%	30.2%	19.0%	1.6%	9.5%	1.6%	0.0%	3.2%	0.0%	100.0%
16+	56.3%	25.0%	6.3%	2.1%	6.3%	2.1%	0.0%	2.1%	0.0%	100.0%
Total	31.1%	18.4%	21.6%	10.1%	10.1%	5.0%	2.3%	1.3%	0.1%	100.0%
Proportion by State (vertical)
0	77.8%	75.8%	76.7%	69.8%	74.6%	88.2%	94.2%	58.5%	100.0%	76.7%
1–5	18.0%	18.4%	19.3%	28.3%	21.9%	10.9%	5.3%	36.8%	0.0%	19.4%
6–10	2.4%	3.8%	3.2%	1.7%	2.3%	0.5%	0.5%	1.9%	0.0%	2.6%
11–15	0.8%	1.2%	0.7%	0.1%	0.7%	0.2%	0.0%	1.9%	0.0%	0.7%
16+	1.0%	0.8%	0.2%	0.1%	0.4%	0.2%	0.0%	0.9%	0.0%	0.6%
Total	100.0%	100.0%	100.0%	100.0%	100.0%	100.0%	100.0%	100.0%	100.0%	100.0%

N/Def means the suburb was not defined in a particular state.

Table 2.

The total population of suburbs with various numbers of dentists in each suburb for all States of Australia

	NSW	VIC	QLD	SA	WA	TAS	NT	ACT	N/Def	Total
Population totals (000’s) for suburbs with different number of practices
0	2,279	1,203	1,495	619	782	321	175	186	3	7,062
1–5	3,032	2,457	2,057	845	1,124	154	23	158	0	9,851
6–10	681	1,061	575	112	204	15	5	4	0	2,656
11–15	328	401	119	6	68	3	0	7	0	931
16+	572	232	57	13	22	2	0	3	0	901
Total	6,891	5,354	4,302	1,595	2,200	495	203	357	3	21,401
Proportion of National (Horizontal)
0	32.3%	17.0%	21.2%	8.8%	11.1%	4.5%	2.5%	2.6%	0.0%	100.0%
1–5	30.8%	24.9%	20.9%	8.6%	11.4%	1.6%	0.2%	1.6%	0.0%	100.0%
6– 10	25.7%	39.9%	21.6%	4.2%	7.7%	0.6%	0.2%	0.2%	0.0%	100.0%
11–15	35.2%	43.1%	12.8%	0.6%	7.3%	0.3%	0.0%	0.7%	0.0%	100.0%
16+	63.5%	25.7%	6.3%	1.4%	2.5%	0.2%	0.0%	0.3%	0.0%	100.0%
Total	32.2%	25.0%	20.1%	7.5%	10.3%	2.3%	0.9%	1.7%	0.0%	100.0%
Proportion by State (vertical)
0	33.1%	22.5%	34.7%	38.8%	35.5%	64.8%	86.3%	52.0%	100.0%	33.0%
1–5	44.0%	45.9%	47.8%	53.0%	51.1%	31.2%	11.5%	44.2%	0.0%	46.0%
6–10	9.9%	19.8%	13.4%	7.0%	9.3%	3.0%	2.2%	1.2%	0.0%	12.4%
11–15	4.8%	7.5%	2.8%	0.4%	3.1%	0.6%	0.0%	1.8%	0.0%	4.4%
16+	8.3%	4.3%	1.3%	0.8%	1.0%	0.4%	0.0%	0.8%	0.0%	4.2%
Non-Zero	66.9%	77.5%	65.3%	61.2%	64.5%	35.2%	13.7%	48.0%		67.0%

N/Def means the suburb was not defined in a particular state.

Of those living within the inclusion zone, 86.6% live within 5 km of a private practice and 84.4% live within 10 km of a government practice (Figure 2). Different proportions of age groups live within 5 km of a private practice or 10 km of a government practice (Figure 3). This ranges from a low (for government practices) of 80% in the 65- to 69-year-old group to a high of 93% for the over 100-year-old age group. For private practice it ranges from a low of 82%, again in the 65- to 69-year-old group, to a high of 93% in the 100-year and older age group.

Figure 2.

A major capital city of Australia with dental practices (blue dots, private practices; red triangles, government practices) with suburb outlines. All suburbs shaded green and brown have centroids within 5 km of a private practice; all suburbs shaded pink or brown have centroids within 10 km of a government practice.

Figure 3.

The proportion of the population (in 5-year age groups) that live within 10 km of a government practice and 5 km of a private practice across Australia.

DISCUSSION

Accessibility to dental services is a complex issue with two main aspects: the first is related to whether a person will make contact with (demand) a service and the second relates to service availability, accessibility (location), affordability, acceptability and accommodation in terms of emergencies, hours open and waiting times. Across the globe the issues of accessibility of health care play a very significant role in the development of countries. In Australia, as a highly developed country ranked well up the Organisation for Economic Co-operation and Development (OECD) rankings of development, it would be expected that a developed accessible health system would be in place and operational. The data from this study find that on a national level there is a clear disparity in the accessibility of dental services (private and public)10., 11..

It is widely acknowledged that economic drivers in a free market determine the distribution of resources. The distribution of private dental services in Australia clearly reflects those drivers¹⁰. The density of dental practices in relatively high-density city regions provides secure economic drivers for business security. Notwithstanding this, it is evident that those resident more distant from these cores suffer inequalities in access. In summary, some 7 million Australians live in suburbs without a dental practice, conversely only 25% of all suburbs have at least one dental practice in them.

The mapping clearly shows that those living in rural areas have a far greater travel burden placed on them in order to access care. This finding is consistent with previous research where both private¹⁰ and government¹¹ accessibility in various States of Australia was examined.

This study examined practice location; it did not examine the number or type of practice operating at each site. It was assumed that all practices listed were operational and actually accessible by patients. Obviously, this is not always the case. Many rural practices only operate part-time while many government practices suffer long waiting-lists and workforce shortages. However, the study is a best-case analysis of the arrangement of services in Australia.

Australia, like many developed countries, is facing a significantly ageing population and the rate of ageing will start to grow rapidly over the next 5–10 years¹². It is evident that the lowest proportions of people living within 5 km of a private and 10 km of a government clinic are those in the retirement age group. It was interesting to note that the curves for age and proximity to private and government practices ran almost perfectly in parallel. Bearing in mind that the government sector is a safety-net sector, it would have been expected that the curves would have been more reflective of the distribution of eligible people (that is, expected to be higher in the retirement and older age groups) but this was not the case. This may reflect the historical location of government practices in areas that were based on the same assumptions as private practices. Our results highlight the need for an analytical approach to planning government services.

CONCLUSION

Market-force driven service planning in dentistry inevitably leads to uneven practice distribution. This distribution of practice service points across a vast and unevenly socio-geographically distributed country such as Australia are then determined by economic drivers of scale and not those of disease burden. There are some 75% of suburbs that have no dental practice and over one-third of the population live in these suburbs. A more population health-driven approach to future design and construction of government safety net services is needed to address these disparities.

Conflicts of Interest

None declared.