Preventive services in Australia by patient and visit characteristics

Abstract

Objectives: Growth in rates of preventive services has been linked to trends in retention of teeth and the emergence of minimal intervention approaches. In this study, we examined associations between patient-level characteristics and rates of the preventive services dental/prophylaxis and application of remineralisation agents. Methods: A random sample of dentists in Australia was posted a self-administered questionnaire in 2009–2010. A service log was used to collect data on preventive services and patient characteristics. Results: Responses were obtained from 1,148 dentists (response rate = 67%). Preventive service rate models, adjusted according to the age and gender of patients, indicated that insured patients had higher rates of prophylaxis [rate ratio (RR) = 1.39; 95% confidence interval (95% CI): 1.21–1.59) and remineralisation services (RR = 1.85; 95% CI: 1.46–2.33), and that emergency visits had lower rates for prophylaxis (RR = 0.26; 95% CI: 0.20–0.35) and remineralisation services (RR = 0.23; 95% CI: 0.14–0.38). Those who had 20 teeth or more demonstrated higher rates of prophylaxis (RR = 1.41; 95% CI: 1.13–1.75) and remineralisation services (RR = 1.45; 95% CI: 1.02–2.08). Those with decayed teeth had lower rates of prophylaxis (RR = 0.54; 95% CI: 0.46–0.63) and remineralisation services (RR = 0.66; 95% CI: 0.53–0.82). Conclusions: Preventive services were associated with patient age, characteristics of visits and oral health. Patients who were worse off, in terms of attending an emergency visit for the relief of pain and having decayed teeth, had lower rates of preventive care. The findings indicate that patients most in need are missing out on the benefits of preventive dental services.

INTRODUCTION

Over the last few decades, dentistry has witnessed a paradigm shift from a surgical model to an evidence-based medical model that is focused more on the diagnosis, early intervention and prevention of oral disease1., 2.. Preventive care is argued as a foundational principle in modern dentistry¹. Newer patient-management approaches, such as minimal intervention dentistry, encourage the least invasive treatment options, accommodating both prevention control and treatment principles³. Preventive care can include services such as dental prophylaxis (removal of plaque and calculus), remineralisation procedures (topical fluoride application), dietary advice, oral hygiene instructions and application of fissure sealants. The move towards prevention is a cost-effective approach to enhance oral health with the aim to promote retention of a natural dentition⁴.

Long-term patterns of attendance for routine dental care may have better oral health outcomes in terms of less tooth loss and less dental caries, and higher levels of self-rated oral health and oral health-related quality of life5., 6., 7., supporting the role of regular dental visiting for preventive check-ups⁸. In contrast, experience of adverse dental episodes, such as visits to a dentist for relief of pain, may lead to higher oral health impacts later in life that may be cumulative over the life course⁹. This probably reflects the different pattern of treatment received by adults, attending for dental problems, who have a mix of services that comprise less preventive care, such as scale and clean services, and more treatment, such as fillings, root canal treatments and extractions¹⁰.

In Australia, the rates of preventive dental services have an increased trend with time, with preventive services being one of the most frequent dental service areas, along with diagnostic and restorative services¹¹. A rise in the provision of preventive services has been observed for both dental prophylaxis and remineralisation services¹². Given the high frequency of preventive services in Australia, and their increasing rate, it is important to investigate preventive services in order to improve knowledge of the characteristics related to variation in preventive care and to understand possible influences on preventive services into the future. The study objective was to assess the rates of two preventive services – dental prophylaxis and remineralisation agents – according to the patient-level characteristics of demographics, factors related to visits and oral health.

METHODS

Australian dentists were randomly sampled from State or Territory dental registers in 1983–1984 using a sampling fraction of 10% for male dentists and 40% for female dentists (as female dentists comprised a lower percentage of registered dentists). A sample supplementation procedure was used across successive study waves to provide representative cross-sectional estimates, using the original sample fractions for newly registered dentists. Participants in these samples were posted a questionnaire in 1983–1984, 1988–1989, 1993–1994, 1998–1999, 2003–2004 and 2009–201013., 14., 15., with the analysis based on the most recent data. Weighted data, based on dental board registration statistics from 2009¹⁶, provided representative estimates according to the age and gender distribution of dentists working in private practice.

Responding dentists logged services from a typical day. The numbers of patients logged by each dentist depended on their activity on that day, and dentists could choose which typical day to have in their log. Instructions indicated to dentists to log services for all patients, irrespective of how the patient was charged. Preventive service items were coded into groupings of dental prophylaxis, application of remineralisation agents and other preventive services, using the Australian Dental Association schedule¹⁷. Dental prophylaxis comprised service items that included removal of plaque and removal of calculus, and service items in the remineralisation agents category included topical and concentrated applications of remineralisation and/or cariostatic agents. Other preventive items included dietary advice, oral hygiene instruction and provision of mouthguards. The category of other preventive services was excluded from the analysis on the basis that it was a small proportion of preventive services.

The characteristics of patients covering demographics, visit factors and oral health status were recorded in the service log. These characteristics included the age and gender of the patient, whether they had insurance and the reason for the visit (emergency visits were classified as involving relief of pain). The oral health variables, number of teeth and number of decayed teeth for each patient were determined by the responding dentist. For analytical purposes, we coded the number of teeth into two categories – 20 teeth or more, or fewer than 20 teeth18., 19.; and decayed teeth were coded into categories that comprised the presence of any decayed teeth or having no decay.

Weighted data were used to produce estimates and tests of statistical significance. Statistical procedures were used to account for design effects (i.e. the clustering of patient-level observations within dentists). This enabled analysis of patient-level characteristics, such as demographics, visit factors and oral health, while accounting for the clustered nature of the data. Service rates per visit were determined by dividing the number of services by the number of visits provided in the typical day, and were presented descriptively as means. Statistical comparisons used Poisson regression with services per visit as the outcome and P < 0.05 as the significance level, using survey procedures (SAS statistical software, version 9.3), with dentist as the cluster variable. Indicator variables were used for the independent variables (coded as 1 or 0) in the adjusted models. The findings from the adjusted models were presented as rate ratios that reflect the rate of services relative to the rate provided in the reference category for each independent variable. The Ethics Committee of the Australian Institute of Health and Welfare provided ethical clearance. The research conforms to the Declaration of Helsinki, with consent implied through the return of completed questionnaires. Patient data collected in the service log were anonymous to the researchers and responding dentist data were de-identified before analysis.

RESULTS

Questionnaires were obtained from 1,148 dentists (response rate = 67%). Table 1 shows that the 45–64 years age group comprised the largest proportion (36.0%) of patients, and that there was a slightly higher percentage of male (55.7%) than female (44.4%) patients. Private dental insurance was held by a majority of patients (62.0%) and most had made visits for reasons that were non-emergency in nature (78.3%). Patients with 20 teeth or more were in the majority (88.1%) and those with one or more decayed tooth accounted for around half of the sample (48.3%).

Table 1.

Distributions of explanatory variables and bivariate associations with preventive services

Variable	Distribution	Prophylaxis services		Remineralisation services
	(%)	Mean	SE	Mean	SE
Patient age		**		**
5–11 years	5.1	0.37	0.04	0.28	0.04
12–17 years	7.7	0.47	0.04	0.24	0.03
18–24 years	7.4	0.40	0.03	0.18	0.02
25–44 years	27.9	0.39	0.03	0.14	0.01
45–64 years	36.0	0.29	0.02	0.10	0.01
65+ years	15.8	0.23	0.02	0.08	0.01
Sex of patient		*
Male	55.7	0.31	0.01	0.13	0.01
Female	44.4	0.35	0.02	0.14	0.01
Insurance status		**		**
Insured	62.0	0.39	0.02	0.17	0.01
Uninsured	38.0	0.24	0.01	0.08	0.01
Reason for visit		**		**
Emergency	21.7	0.09	0.01	0.03	0.01
Non-emergency	78.3	0.41	0.02	0.17	0.01
Number of teeth		**		**
< 20 teeth	11.9	0.18	0.02	0.07	0.01
20+ teeth	88.1	0.36	0.02	0.14	0.01
Decayed teeth		**		**
No decayed teeth	51.7	0.44	0.02	0.17	0.01
1+ decayed tooth	48.3	0.21	0.01	0.09	0.01

^*P < 0.05; **P < 0.01 (Poisson regression).

SE, standard error.

Removal of calculus and topical remineralisation were the most commonly provided preventive service items (Figure 1). Much lower rates were observed for the remaining preventive service items, with the next highest being for fissure sealing, then for removal of plaque and then for oral hygiene instruction.

Figure 1.

Rates of preventive services per visit for the most common preventive procedures. 95% CI, 95% confidence interval.

Both prophylaxis and remineralisation services were inversely related to the age of the patient, with lower rates observed among older patients (Table 1). Although the number of remineralisation services per visit were not related to gender of the patient, there were higher prophylaxis service rates for female patients than for male patients. Higher rates of both prophylaxis and remineralisation services were observed for patients with insurance coverage and for patients making visits for non-emergency reasons. Patients who had more teeth and patients with no decay present had higher rates of prophylaxis and remineralisation services.

Table 2 shows that in models of preventive services the rates of prophylaxis services were significantly lower for older patients ≥ 65 years of age [rate ratio (RR) = 0.76; 95% confidence interval (95% CI): 0.59–0.97] compared with the reference category of those 5–11 years of age. The rates of remineralisation services were significantly lower among patients in the age categories 25–44 (RR = 0.58; 95% CI: 0.42–0.79), 45–64 (RR = 0.44; 95% CI: 0.32–0.60) and ≥65 (RR = 0.40; 95% CI: 0.26–0.60) years, in comparison with the reference category of 5–11 years. The rates of preventive services were not related to patient gender. Insured patients had significantly higher rates of prophylaxis (RR = 1.39; 95% CI: 1.21–1.59) and remineralisation services (RR = 1.85; 95% CI: 1.46–2.33), and there were significantly lower rates of prophylaxis (RR = 0.26; 95% CI: 0.20–0.35) and remineralisation services (RR = 0.23; 95% CI: 0.14–0.38) for emergency visits. Having 20 or more teeth was associated with significantly higher rates of prophylaxis (RR = 1.41; 95% CI: 1.13–1.75) and remineralisation services (RR = 1.45; 95% CI: 1.02–2.08). Significantly lower rates of prophylaxis (RR = 0.54; 95% CI: 0.46–0.63) and remineralisation services (RR = 0.66; 95% CI: 0.53–0.82) were related to the presence of decayed teeth.

Table 2.

Adjusted models of preventive service rates

Variable	Prophylaxis services		Remineralisation services
	RR	95% CI	RR	95% CI
Patient age
5–11 years	Ref		Ref
12–17 years	1.08	0.85–1.36	0.77	0.56–1.06
18–24 years	1.11	0.88–1.39	0.71	0.50–1.03
25–44 years	1.18	0.91–1.54	0.58**	0.42–0.79
45–64 years	0.88	0.72–1.09	0.44**	0.32–0.60
65+ years	0.76*	0.59–0.97	0.40**	0.26–0.60
Sex of patient
Male	0.95	0.84–1.07	0.99	0.86–1.13
Female	Ref		Ref
Insurance status
Insured	1.39**	1.21–1.59	1.85**	1.46–2.33
Uninsured	Ref		Ref
Reason for visit
Emergency	0.26**	0.20–0.35	0.23**	0.14–0.38
Non-emergency	Ref		Ref
Number of teeth
< 20 teeth	Ref		Ref
20+ teeth	1.41**	1.13–1.75	1.45*	1.02–2.08
Decayed teeth
No decayed teeth	Ref		Ref
&geq 1 decayed tooth	0.54**	0.46–0.63	0.66**	0.53–0.82

^*P < 0.05; **P < 0.01 (Poisson regression).

95% CI, 95% confidence interval; Ref, reference category; RR, rate ratio.

DISCUSSION

The study findings indicate that the rates of the two most common categories of preventive services, prophylaxis and remineralisation, demonstrated variation according to characteristics spanning patient demographics, visit factors and oral health. A common pattern was observed for both prophylaxis and remineralisation services, comprising lower rates for older patients, those attending for emergency reasons and those with decayed teeth. In contrast, higher rates were observed for prophylaxis and remineralisation services for insured patients and those with a higher number of natural teeth.

The findings come from a national survey that was drawn from a sampling frame that may be considered comprehensive, and the response rate was adequate. The findings are weighted to produce representative estimates of private general practice in Australia. The majority (78%) of Australian dentists work in private practice only, and 88% of the population ≥ 5 years of age who made a dental visit in the last year reported last visiting a private dentist²⁰. However, a potential limitation is that dental service rates vary between the private and public sectors²¹ and according to the geographical location22., 23., as these may reflect different delivery systems with potentially different patient pools and disease patterns. For example, the percentage of people who attend a public sector dentist tends to be higher among lower-income groups; and public dental care is reported to have higher levels of emergency care and service profiles, with higher extraction rates, than the private sector²¹. Further research is required to investigate whether similar patterns of preventive services apply to public sector and rural locations. An additional consideration is that of bias emanating from the collection of data on services using a self-selection method based on a typical day. However, significant differences in service rates were not found when data that were collected over a sampling period of 10 days were assessed against estimates from a single typical day²⁴.

Rates of prophylaxis services were lowest in the older age group, which could reflect the higher rates of tooth loss among older adults. However, the lower rate of dental prophylaxis persisted in the adjusted model that included number of teeth. This could indicate other potential reasons for such age-related service patterns, such as routines in clinical decision making and in practice styles of dental providers24., 25.. The rates of remineralisation services were also lower among older age groups and exhibited a consistent gradient in service rates from children to younger and middle-aged adult age groups and finally to older adults. This is not consistent with the prevalence of decay in adults, which has been shown to occur at a similar level across all adult age groups in Australia²⁶. Therefore, it is possible that minimal intervention dentistry in adults could be expanded. Minimal intervention approaches involve an evidence-based rationale for preventive and cause-related management of oral diseases²⁷. However, initial and cavitated carious lesions tend to be treated similarly through restorative interventions28., 29.. This may reflect difficulties in adopting evidence-based preventive care, which requires considerable effort, motivation and coordination by a dental practice³⁰, and account for the substantial variation reported in practice patterns of dentists related to preventive dentistry³¹.

In this study, it was found that having dental insurance was related to higher rates of dental prophylaxis services as well as of remineralisation services. Insurance is generally considered as an enabling variable that can facilitate access³² and is also consistent with more favourable service patterns, such as more preventive care but lower likelihood of extractions³³. Those on lower incomes tend to have lower coverage for dental insurance than those on higher incomes³⁴, and increases in income-related inequality in dental care use have been reported³⁵. However, benefits from insurance may be greater among lower socio-economic status groups in terms of visiting and oral health36., 37., so policies that could improve insurance coverage for those on lower incomes may be beneficial.

Emergency visits for the relief of pain tend to be more prevalent among lower income groups, but adjusted models have shown lack of insurance and the presence of oral health impacts to be significantly associated with visits because of an emergency³⁸. In this study, emergency visits and worse oral health status were related to lower preventive service rates. Visit patterns for relief of pain may work against preventive treatment decisions and create a paradoxical situation in which those who are worse off in relation to oral health and dental-care access are less likely to receive preventive services. Oral health inequalities have been demonstrated in relation to tooth loss, periodontal disease and caries for measures of social position, such as education, occupation and income39., 40., 41.. Oral health policy to maintain good oral health recognises the need for services, such as promotion of health, prevention and early intervention, that are appropriate and affordable, as well as for treatment, across the whole population⁴².

CONCLUSIONS

Preventive services were related to the age of the patient, characteristics of visits and to oral health. The similar pattern of associations for both prophylaxis and remineralisation services suggests that patients who are better off in relation to possessing dental insurance and having a higher number of teeth, have a greater likelihood of receiving dental care of a preventive nature. In contrast, those worse off, in terms of attending for an emergency visit for relief of pain and having decayed teeth, have a lower likelihood of receipt of preventive services. This could indicate that those most in need are missing out on the benefits of preventive dental care. It is important for dentistry to focus on prevention and to support the concept of a healthy dentition for life.

Acknowledgements

This work was supported by the Australian Government Department of Health and Ageing, National Health and Medical Research Council (NHMRC), and Australian Institute of Health and Welfare and was written with support from the NHMRC (1031310). The contents are the responsibility of the administering institution and authors, and do not reflect the views of the NHMRC.

Competing interests

The authors declare no conflicts of interest.