Xiangqun Ju

Inequalities in Indigenous Oral Health: Findings from Australia, New Zealand, and Canada:

The objective was to compare absolute differences in the prevalence of Indigenous-related inequalities in dental disease experience and self-rated oral health in Australia, Canada, and New Zealand. Data were sourced from national oral health surveys in Australia (2004 to 2006), Canada (2007 to 2009), and New Zealand (2009). Participants were aged ≥18 y. The authors measured age- and sex-adjusted inequalities by estimating absolute prevalence differences and their corresponding 95% confidence intervals (95% CIs). Clinical measures included the prevalence of untreated decayed teeth, missing teeth, and filled teeth; self-reported measures included the prevalence of “fair” or “poor” self-rated oral health. The overall pattern of Indigenous disadvantage was similar across all countries. The summary estimates for the adjusted prevalence differences were as follows: 16.5 (95% CI: 11.1 to 21.9) for decayed teeth (all countries combined), 18.2 (95% CI: 12.5 to 24.0) for missing teeth, 0.8 (95% CI: –1.9 to 3.5) for filled teeth, and 17.5 (95% CI: 11.3 to 23.6) for fair/poor self-rated oral health. The I2 estimates were small for each outcome: 0.0% for decayed, missing, and filled teeth and 11.6% for fair/poor self-rated oral health. Irrespective of country, when compared with their non-Indigenous counterparts, Indigenous persons had more untreated dental caries and missing teeth, fewer teeth that had been restored (with the exception of Canada), and a higher proportion reporting fair/poor self-rated oral health. There were no discernible differences among the 3 countries.

Age, period and cohort analysis of patient dental visits in Australia

BackgroundUnderstanding dentists’ capacity to supply dental services over time is a key element in the process of planning for the future. The aim was to identify time trends and estimate age, period and cohort effects in patients’ visits supplied per dentist per year.MethodsMailed questionnaires were collected from a random sample of Australian private general practice dentists. The response rates were 73%, 75%, 74%, 71%, 76% and 67% in 1983, 1988, 1993, 1998, 2003 and 2009, respectively. The time trends in the mean number of patient visits supplied per dentist per year (PPY) was described by using a standard cohort table and age-period-cohort analyses applying a nested general linear regression models approach.ResultsThe mean number of PPY decreased across most age groups of dentists over the time of study. The age-period model showed that younger dentists (20–29 years) and older dentists (65–74 and 80–84 years) had lower PPY than middle-aged dentists, and the age-cohort model showed higher PPY among earlier cohorts, and lower PPY among more recent cohorts.ConclusionThe study found a period effect of declining PPY over the observation period. More recent cohorts of dentists provide lower numbers of PPY than earlier cohorts at similar ages, but the provision of PPY among these younger cohorts appeared to be stable as they moved into middle age.

Longitudinal changes in dental services provided by Australian dentists

OBJECTIVE To estimate the longitudinal change in number of patients per year (PPY) per dentist by age and sex of dentists in Australia. METHOD Dentists were selected randomly from Australian dental registers, the baseline collection was in 1983 and repeated approximately every 5 years until 2009. Dentists practice activity was collected by mailed questionnaire. Number of PPY was calculated from work hours and number of patients per week per dentist. Mixed-effects regression was applied to estimate both individual random effects and population averaged fixed effects for the number of PPY provided by age, time, and sex. RESULTS A total of 1,449 dentists completed 2,822 questionnaires from six waves of data collection (1983 to 2010). The average PPY decreased over the time of the study. The rate of change in PPY accelerated during younger ages and reached a peak when they moved into 50 years old (B = 86.04, P < 0.0001), and then decelerated (B = -0.90, P = 0.0002) across time. The mean number of PPY was higher in male dentists than female dentists in the same 10-year age group. The pattern of PPY change with aging was an inverted U-shape for male dentists. In contrast, there was a U-shape for female dentists. CONCLUSIONS The longitudinal change in PPY with aging was an inverted U-shape, which accelerated during younger age, and decelerated after reaching a peak at 50 years old. Males had higher PPY than female dentists at the same age. The pattern of PPY was different between male and female dentists.

Dental responsibility loadings and the relative value of dental services

OBJECTIVE To estimate responsibility loadings for a comprehensive list of dental services, providing a standardized unit of clinical work effort. METHODS Dentists (n = 2500) randomly sampled from the Australian Dental Association membership (2011) were randomly assigned to one of 25 panels. Panels were surveyed by questionnaires eliciting responsibility loadings for eight common dental services (core items) and approximately 12 other items unique to that questionnaire. In total, loadings were elicited for 299 items listed in the Australian Dental Schedule 9th Edition. Data were weighted to reflect the age and sex distribution of the workforce. To assess reliability, regression models assessed differences in core item loadings by panel assignment. Estimated loadings were described by reporting the median and mean. RESULTS Response rate was 37%. Panel composition did not vary by practitioner characteristics. Core item loadings did not vary by panel assignment. Oral surgery and endodontic service areas had the highest proportion (91%) of services with median loadings ≥1.5, followed by prosthodontics (78%), periodontics (76%), orthodontics (63%), restorative (62%) and diagnostic services (31%). Preventive services had median loadings ≤1.25. CONCLUSION Dental responsibility loadings estimated by this study can be applied in the development of relative value scales.

Human Papillomavirus and Oropharyngeal Cancer Among Indigenous Australians: Protocol for a Prevalence Study of Oral-Related Human Papillomavirus and Cost-Effectiveness of Prevention

Background Oropharyngeal cancer is an important, understudied cancer affecting Aboriginal and Torres Strait Islander Australians. The human papillomavirus (HPV) is a significant risk factor for oropharyngeal cancer. Current generation HPV vaccines are effective against the 2 most common types of high-risk HPVs in cancer (hrHPVs 16/18). Objectives This study aims (1) to yield population estimates of oncogenic genotypes of HPV in the mouth and oropharynx of defined Aboriginal and Torres Strait Islander populations; (2) to estimate the proportion of oropharyngeal cancer attributable to HPV among these Australian citizens; (3) to estimate the impact of HPV vaccination as currently implemented on rates of oropharyngeal cancer among Aboriginal and Torres Strait Islander Australians; and (4) taking into account impact on oropharyngeal as well as cervical cancer, to evaluate efficacy and cost-effectiveness of targeted extended HPV vaccination to older ages, among our study population. Methods Our study design and operation is straightforward, with minimal impost on participants. It involves testing for carriage of hrHPV in the mouth and oropharynx among 1000 Aboriginal South Australians by simple saliva collection and with follow-up at 12 and 24 months, collection of sexual history at baseline, collection of information for estimating health state (quality-of-life) utilities at baseline, genotyping of viruses, predictive outcome and cost-effectiveness modeling, data interpretation and development of vaccination, and follow-up management strategies driven by the Aboriginal community. Results Participant recruitment for this study commenced in February 2018 and enrollment is ongoing. The first results are expected to be submitted for publication in 2019. Conclusions The project will have a number of important outcomes. Synthesis of evidence will enable generation of estimates of the burden of oropharyngeal cancer among Aboriginal and Torres Strait Islander Australians and indicate the likely effectiveness and cost-effectiveness of prevention. This will be important for health services planning, and for Aboriginal health worker and patient education. The results will also point to important areas where research efforts should be focused to improve outcomes in Aboriginal and Torres Strait Islander Australians with oropharyngeal cancer. There will be a strong focus on community engagement and accounting for the preferences of individuals and the community in control of HPV-related cancers. The project has international relevance in that it will be the first to systematically evaluate prevention of both cervical and oropharyngeal cancer in a high-risk Indigenous population taking into account all population, testing, and surveillance options. Registered Report Identifier RR1-10.2196/10503

Dental Disease Outcomes Following a 2-Year Oral Health Promotion Program for Australian Aboriginal Children and Their Families: A 2-Arm Parallel, Single-blind, Randomised Controlled Trial

Background Dental disease has far-reaching impacts on child health and wellbeing. We worked with Aboriginal Australian communities to develop a multifaceted oral health promotion initiative to reduce childrens experience of dental disease at age 2 years. Methods This was a single-blind, parallel-arm, randomised controlled trial. Participants were recruited from health service providers across South Australia. Women pregnant with an Aboriginal child were eligible. The intervention comprised: (1) provision of dental care to mothers during pregnancy; (2) application of fluoride varnish to teeth of children at ages 6, 12 and 18 months; (3) motivational interviewing delivered in conjunction with; (4) anticipatory guidance. The primary outcome was untreated dental decay as assessed by the number of teeth with cavitated and non-cavitated carious lesions (mean dt) at child age 24 months. Analyses followed intention-to-treat principles. The RCT was registered with the Australian and New Zealand Clinical Trial Registry, ACTRN12611000111976. Findings Women (n = 448) were recruited from February 2011 to May 2012, resulting in 223 children in the treatment group and 225 in the control. Mean dt at age two years was 0.62 (95% CI 0.59 to 0.65) for the intervention group and 0.89 (95% CI 0.85 to 0.92) for the control group (mean difference − 0.27 (95% CI − 0.31, − 0.22)). Interpretation A culturally-appropriate intervention at four time-points from pregnancy through to 18-months resulted in improvements in the oral health of Aboriginal children. Further consultation with Aboriginal communities is essential for understanding how to best sustain these oral health improvements for young Aboriginal children.

Socioeconomic status, oral health and dental disease in Australia, Canada, New Zealand and the United States

BackgroundSocioeconomic inequalities are associated with oral health status, either subjectively (self-rated oral health) or objectively (clinically-diagnosed dental diseases). The aim of this study is to compare the magnitude of socioeconomic inequality in oral health and dental disease among adults in Australia, Canada, New Zealand and the United States (US).MethodsNationally-representative survey examination data were used to calculate adjusted absolute differences (AD) in prevalence of untreated decay and fair/poor self-rated oral health (SROH) in income and education. We pooled age- and gender-adjusted inequality estimates using random effects meta-analysis.ResultsNew Zealand demonstrated the highest adjusted estimate for untreated decay; the US showed the highest adjusted prevalence of fair/poor SROH. The meta-analysis showed little heterogeneity across countries for the prevalence of decayed teeth; the pooled ADs were 19.7 (95% CI = 16.7–22.7) and 12.0 (95% CI = 8.4–15.7) between highest and lowest education and income groups, respectively. There was heterogeneity in the mean number of decayed teeth and in fair/poor SROH. New Zealand had the widest inequality in decay (education AD = 0.8; 95% CI = 0.4–1.2; income AD = 1.0; 95% CI = 0.5–1.5) and the US the widest inequality in fair/poor SROH (education AD = 40.4; 95% CI = 35.2–45.5; income AD = 20.5; 95% CI = 13.0–27.9).ConclusionsThe differences in estimates, and variation in the magnitude of inequality, suggest the need for further examining socio-cultural and contextual determinants of oral health and dental disease in both the included and other countries.

Longitudinal Changes in Proportions of Dental Services Provided by Australian Dentists, 1983 to 2010:

The objective of the study was to estimate the longitudinal change over a 26-y period in the proportion of dental services provided in 10 main service provision areas by Australian dentists. A random sample of Australian dentists was surveyed approximately every 5 y, commencing 1983 to 1984. The mean proportion of dental services provided was calculated from practitioner activity logs. Mixed effects regression models estimated the longitudinal change in the proportion of services provided, by dentists’ age and birth-year cohort. Response rates across data collection waves ranged from 67% to 76%. Between 1983 to 1984 and 2009 to 2010, the mean proportion of diagnostic, preventive, and crown/bridge services provided tended to increase, and the mean proportion of restorative, oral surgery, and prosthodontic services tended to decrease. Mean proportions of endodontic and orthodontic services fluctuated. Relative to the youngest cohort (born after 1984), across cohorts of older to younger dentists, the proportions of diagnostic and preventive services increased, and restorative and prosthodontic decreased. Older cohorts provided the lowest proportions of diagnostic and preventive services (oldest cohort born before 1918: β = −32.1 ± 4.8; cohort born 1934 to 1938: β = −11.6 ± 3.2, respectively). Older cohorts provided the highest proportions of restorative and prosthodontic services (born before 1918: β = 27.3 ± 5.6; born 1919 to 1923: β = 10.5 ± 2.4, respectively). Some service area trends varied across birth-year cohorts. Endodontic service provision was declining for younger cohorts but increasing for older cohorts. Preventive service provision was increasing for younger cohorts but declining for older cohorts. This study identified trends not evident in previous time-series analysis. First, provision of restorative and oral surgery services, as a proportion of all services provided, was declining. Second, there were competing intercohort trends. These may indicate that new norms in dental education are influencing clinical decision making and that new trends in dental service provision may emerge as older dentists retire. Knowledge Transfer Statement: This study identified several trends in dental service provision and indicated that not all trends were consistent across all birth-year cohorts. Findings inform dental health care policy and priorities for dental education. In addition, the identified trends have implications for the future composition of the oral health workforce.