Causal inference in dentistry: Time to move forward.

Oral conditions represent a critical public health challenge, and together with descriptive and predictive epidemiology, causal inference has a crucial role in developing and testing preventive oral health interventions. By identifying not just correlations but actual causes of disease, causal inference may quantify the average effect of interventions and guide policies. Although authors are not usually explicit about it, most oral health studies are guided by causal questions. However, methodological deficiencies limit their interpretability and the implementation of their findings. This manuscript is a call to action on the use of causal inference in oral research. Its application starts with asking theoretically sound questions and being explicit about causal relationships, defining the estimates to evaluate, and measuring them properly. Beyond promoting causal analytical approaches, we emphasize the need for more causal thinking to promote thoughtful research questions and the use of appropriate methods to answer them. Causal inference relies on the plausibility of assumptions underlying the data analysis and the quality of the data, and we argue that high-quality observational studies can be used to estimate average causal effects. Although individual efforts to embrace causal inference in dentistry are essential, they will not yield substantial results if not led by a systematic and structural change in the field. We urge scientific societies, funding bodies, dental schools, and journals to promote transparency in research, causal thinking, and causal inference projects to move the field toward more meaningful studies. It is also time for researchers to move forward and connect with the community, co-produce investigations and translate their findings, and engage in interventions that impact public health. We conclude by highlighting the importance of triangulating results from different data sources and methods to support causal inference and inform decision-making on interventions to effectively improve population oral health.

Gender inequities in dental research publications: Findings from 20 years.

BACKGROUND: The first steps towards gender equity in science are measuring the magnitude of inequity and increasing awareness of the problem. OBJECTIVES: To describe trends in gender disparities in first and last authorship in the most cited dental publications and general dental literature over a 20-year period. METHODS: Articles and bibliometric data were retrieved from the Scopus database for the period 1996 to 2015. Two groups of 1000 articles each were retrieved: a random sample and another sample of top-cited articles for each year. The gender of the first and last author of each publication was manually identified. When this was not possible, we used an online software platform (https://genderize.io/). Descriptive analyses identified the proportion of women first and last authors in both samples, stratifying by dental discipline and geographic region. Trends were ascertained by frequency metrics across years. Gender disparity was observed in both first and last authorship, with a larger gap being observed in the top-cited sample. RESULTS: Women led 28.4% and 20.3% of articles in the random and top-cited samples, respectively. A similar pattern was observed for the last authorship group (22.1% and 16.1%, respectively). An increasing trend in the proportion of articles led by women over time was observed in both samples. This increase was larger in the top-cited sample (from 15.0% in 1996-2000 to 25.1% in 2015) than in the random sample (from 26.3% in 1996-2000 to 33.2% in 2011). CONCLUSIONS: Clear gender disparities in dental research publications in the last 20 years were identified in both general and top-cited manuscripts, across dental disciplines, across countries, across first and last authorship, and over time. It is paramount that actions are taken to attract, retain and promote women in science, as well as to monitor and ensure progress towards gender equity.

Application of multilevel models for predicting pain following root canal treatment.

OBJECTIVES: This study developed predictive models for one-week acute and six-month persistent pain following root canal treatment (RCT). An additional aim was to study the gain in predictive efficacy of models containing clinical factors only, over models containing sociodemographic characteristics. METHODS: A secondary data analysis of 708 patients who received RCTs was conducted. Three sets of predictors were used: (1) combined set, containing all predictors in the data set; (2) clinical set and (3) sociodemographic set. Missing data were handled by multiple imputation using the missing indicator method. The multilevel least absolute selection and shrinkage operator (LASSO) regression was used to select predictors into the final multilevel logistic models. Three measures, the area under the receiver operating characteristic curve (AUROC) and precision-recall curve (AUPRC) and calibration curves, were used to assess the predictive performance of the models. RESULTS: The selected-in factors in the final models, using LASSO regression, are related to pre- and intra-treatment clinical symptoms and pain experience. Predictive performance of the models remained the same with the inclusion (exclusion) of the socio-demographic factors. For predicting one-week outcome, the model built with combined set of predictors yielded the highest AUROC and AUPRC of 0.85 and 0.72, followed by the models built with clinical factors (AUROC = 0.82, AUPRC = 0.66). The lowest predictive ability was found in models with only sociodemographic characteristics (AUROC = 0.68, AUPRC = 0.40). Similar patterns were observed in predicting six-month outcome, where the AUROC for models with combined, clinical and sociodemographic sets of predictors were 0.85, 0.89 and 0.66, respectively, and the AUPRC were 0.48, 0.53 and 0.22, respectively. CONCLUSIONS: Clinical factors such as the severity and experience of pre-operative and intra-operative pain were discovered important to the subsequent development of pain following RCTs. Adding sociodemographic characteristics to the models with clinical factors did not change the models' predictive performance or the proportion of explained variance.

Self-efficacy and oral health outcomes in a regional Australian Aboriginal population.

BACKGROUND: Perceived self-efficacy has been associated with psychological well-being, health behaviours and health outcomes. Little is known about the influence of self-efficacy on oral health outcomes for Aboriginal adults in Australia, a population experiencing high levels of oral health conditions. This study examines associations between oral health-related self-efficacy and oral health outcomes in a regional Aboriginal Australian population and investigates whether the associations persist after adjusting for sociodemographic characteristics and other general and oral health-related psychosocial factors. METHODS: Cross-sectional data were obtained from the baseline questionnaire of the Indigenous Oral Heath Literacy Project, South Australia. Oral health-related self-efficacy was measured using a six item scale, with total sum scores dichotomised into high/low self-efficacy. Oral health outcomes included self-rated oral health and oral health impacts, measured using the Oral Health Impact Profile (OHIP-14). Generalized linear models with a log-Poisson link function were used to estimate Prevalence Ratios (PR) of poor self-rated oral health according to levels of oral health-related self-efficacy. Multivariable linear regressions were used to estimate the association between oral health-related self-efficacy and OHIP-14 scores. Blocks of confounders were subsequently added into the models, with the final model including all factors. RESULTS: Complete data were available for 252 participants (63%) aged 18 to 82 years (mean age of 37.6 years). Oral health-related self-efficacy was associated with poor self-rated oral health, with a 43% (PR = 1.43 (95% CI 1.09, 1.88)) greater prevalence of poor self-rated oral health among those with low self-efficacy. Oral health-related self-efficacy was associated with OHIP-14 severity scores, with a score over six points higher for those with low self-efficacy (B = 6.27 95% CI 2.71, 9.83). Although addition of perceived stress into the models attenuated the relationship, associations remained in the final models. CONCLUSION: Lower levels of oral health-related self-efficacy were associated with a higher prevalence of poor self-rated oral health and greater impacts of oral health among Aboriginal adults in regional South Australia. These associations persisted after controlling for sociodemographic and psychosocial confounders, suggesting that increasing self-efficacy may provide an opportunity for improving oral health outcomes for Aboriginal adults.

Oral health promotion and programming provided by Aboriginal Community Controlled Health Organisations in South Australia.

BACKGROUND: Aboriginal Community Controlled Health Organisations (ACCHOs) play a critical role in supporting Aboriginal and Torres Strait Islander health in Australia. This article aims to identify and describe oral health programming and promotion provided by ACCHOs in South Australia. METHODS: All ACCHOs in South Australia were identified through the Aboriginal Health Council of South Australia. A targeted search strategy was designed to include the websites and social media pages (Facebook, Twitter, Instagram) for each organisation. Program characteristics were extracted and summarised, and oral health promotion content was analysed utilising content analysis. RESULTS: Twelve programs were identified across the 12 ACCHOs in South Australia. Of these, seven focused on oral health and five focused on nutrition. Oral health and nutrition information shared online by ACCHOs was extracted and aggregated into oral health and nutrition categories, which included reminders about visiting services, advocacy statements, oral hygiene messaging, appointment availability, education resources, and upcoming community-based activities. CONCLUSIONS: The evidence explored highlights the integral role ACCHOs play in oral health promotion and service delivery. It is critically important that ACCHOs are involved in development and implementation of oral health services to ensure programming reflects community knowledges and is effective in improving oral health equity.

Dental Health Inequalities among Indigenous Populations: A Systematic Review and Meta-Analysis.

The aim of this systematic review and meta-analysis was to document the disparity in dental caries experiences among indigenous and nonindigenous populations globally by measuring dental caries prevalence and severity. An electronic database (MEDLINE) was initially searched using relevant keywords. This was followed by use of the search string in the following electronic databases: Scopus, EBSCOhost, Cochrane, and Open Grey. Two independent reviewers conducted the study search and screening, quality assessment, and data extraction, which was facilitated using JBI SUMARI software. The primary outcome was the decayed missing filled teeth (DMFT) score and dental caries prevalence. Subgroup analysis was done by country of publication to identify causes of heterogeneity. Forest plots were used with the standardized mean difference (SMD) and publication bias was assessed using the Egger test with funnel plot construction. For the final review, 43 articles were selected and 34 were meta-analyzed. The pooled mean DMFT for both the permanent dentition (SMD = 0.26; 95% CI 0.13-0.39) and deciduous dentition (SMD = 0.67; 95% CI 0.47-0.87) was higher for the Indigenous population than for the general population. Indigenous populations experienced more decayed teeth (SMD = 0.44; 95% CI 0.25-0.62), a slightly higher number of missing teeth (SMD = 0.11< 95% CI -0.05 to 0.26), and lesser filled teeth (SMD = -0.04; 95% CI -0.20 to 0.13) than their nonindigenous counterparts. The prevalence of dental caries (SMD = 0.27; 95% CI 0.13-0.41) was higher among indigenous people. Globally, indigenous populations have a higher caries prevalence and severity than nonindigenous populations. The factors which have led to such inequities need to be examined.

Prevalence of dental caries among Indigenous populations compared to non-Indigenous populations: a quantitative systematic review protocol.

OBJECTIVE: The objective of this review is to evaluate if the prevalence of dental caries is higher among Indigenous populations compared to non-Indigenous populations. INTRODUCTION: Globally, Indigenous populations have experienced substantial inequalities in health, including oral health care, when compared to their non-Indigenous counterparts. Indigenous populations experience a higher prevalence of dental caries, but most of this data has been collected from convenience samples not involving non-Indigenous groups. This review will highlight differences in the prevalence of dental caries globally among Indigenous groups compared to non-Indigenous groups. INCLUSION CRITERIA: The systematic review will include all studies that have compared the prevalence of dental caries (% of decayed teeth>0) and dental caries experience (mean score of decayed, missing, filled teeth) among Indigenous and non-Indigenous populations across all ages. METHODS: Initially, articles will be searched in MEDLINE, followed by a more comprehensive search on Scopus, EBSCO (Dentistry and Oral Sciences Sources), Cochrane Database, and OpenGrey. The search will be conducted independently by two reviewers from database inception to September 2020. A reference list will be made identifying all eligible studies. Titles and abstracts will be reviewed, as well as the full text of articles that meet the inclusion criteria. To assess methodological quality, a standardized critical appraisal checklist for studies reporting prevalence will be selected, followed by standardized data extraction using the JBI tool. The results from included studies will be analyzed using JBI SUMARI. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO CRD42020204311.

Development and initial psychometric assessment of the race-related attitudes and multiculturalism scale in Australia.

AIM: The present study aims to develop the Race-related Attitudes and Multiculturalism Scale (RRAMS), as well as to perform an initial psychometric assessment of this instrument in a national sample of Australian adults. METHODS: The sample comprised 2,714 Australian adults who took part in the 2013 National Dental Telephone Interview Survey (NDTIS), which includes a telephone-based interview and a follow-up postal questionnaire. We used Exploratory Factor Analysis (EFA) to evaluate the RRAMS' factorial structure (n = 271) and then proceeded with Confirmatory Factor Analysis (CFA) to confirm the proposed structure in an independent sample (n = 2,443). Measurement invariance was evaluated according to sex, age and educational attainment. Construct validity was assessed through known-groups comparisons. Internal consistency was assessed with McDonald's ΩH and ordinal α. Multiple imputation by chained equations was adopted to handle missing data. RESULTS: EFA indicated that, after excluding 4 out of the 12 items, a two-factor structure provided a good fit to the data. This configural structure was then confirmed in an independent sample by means of CFA (χ2(19) = 341.070, p<0.001, CFI = 0.974, RMSEA = 0.083; 90% CI [0.076, 0.091]). Measurement invariance analyses suggested that the RRAMS items can be used to compare men/women, respondents with/without tertiary education and young/older participants. The "Anglo-centric/Assimilationist attitudes" (ΩH = 0.83, αORDINAL = 0.85) and "Inclusive/Pluralistic attitudes" subscales (ΩH = 0.77, αORDINAL = 0.79) showed adequate reliability. Men and participants with low education had higher Anglo-centric/assimilationist attitudes and lower inclusive/pluralistic attitudes, suggesting construct validity. CONCLUSIONS: The RRAMS appears to be a valid and reliable measure to evaluate multiculturalist attitudes in the Australian context. The instrument may be useful in the assessment and monitoring of interventions aiming to promote multiculturalist inclusive attitudes and to increase social cohesion in Australia.

Direct effect of common mental disorders on xerostomia in adults estimated by marginal structural models: A population-based study.

OBJECTIVE: To investigate the controlled direct effect (CDE) of common mental disorders (CMD) on xerostomia which is not mediated by psychoactive medication intake. METHODS: A population-based cross-sectional study was conducted with 1720 individuals aged 20-59 years from Florianópolis, Brazil, in 2009. A two-stage cluster sample design was adopted, with a systematic selection of census tracts, followed by a random selection of households. All inhabitants of the selected households belonging to the age group of interest were considered eligible to participate. CMD were assessed using the Self-Reporting Questionnaire (SRQ > 7). Xerostomia was the outcome assessed by asking: "How often do you feel dry mouth?" with responses "often" and "always" taken as indicating xerostomia. Psychoactive medication intake was set as the mediator. Confounding factors included sex, age, per capita family income, educational attainment and smoking status. Marginal structural models were performed to quantify the CDE of CMD on xerostomia. Missing data were handled by multiple imputation by chained equations, and sensitivity analysis for unmeasured confounding was carried out. RESULTS: The overall prevalence of xerostomia was 8.8% and 15.3% of the individuals presented with CMD. After adjustment, the prevalence of xerostomia among individuals with CMD was 3.2 times higher than that among individuals without CMD (PR = 3.2 [95% CI: 2.3; 4.5]). The CDE of CMD on xerostomia which is not mediated by the medication intake resulted in a three times greater prevalence of xerostomia (PR = 3.0 95% CI: 2.0; 4.5) among those individuals with CMD. CONCLUSIONS: Common mental disorders is directly and negatively associated with xerostomia. Clinicians should bear in mind the emotional state when investigating the underlying factors and managing patients with xerostomia.

Physical activity moderates the deleterious relationship between cardiovascular disease, or its risk factors, and quality of life: Findings from two population-based cohort studies in Southern Brazil and South Australia.

BACKGROUND: Few studies have investigated the relationship between physical activity (PA) of low intensity and duration with quality of life (QoL) among individuals at risk or with cardiovascular disease (CVD). OBJECTIVES: To investigate whether PA of different intensity and duration moderates the relationship between CVD and its risk factors (obesity, hypertension, diabetes, dyslipidaemia) and QoL in adults. METHODS: Population-based cross-sectional studies using data from the EpiFloripa Cohort Study (Southern Brazil; n = 1,220, 38.8±12.0 years, 48.2% males) and the North West Adelaide Health Study (NWAHS, South Australia; n = 1,661, 43.7±11.1 years, 49.7% males). The physical and psychological domains of QoL were assessed using the WHOQOL-Bref (EpiFloripa) or the SF-36 (NWAHS) questionnaires. The diagnosis of CVD and its risk factors were self-reported. PA was self-reported and quantified by its intensity ["walking" or moderate/vigorous (MVPA)] and duration (none, 1-150, ≥150 min/week). Both studies were analysed separately, and results were adjusted for sociodemographic variables. RESULTS: Participants at risk or with CVD from both studies showed a lower QoL than 'healthy' individuals with a stronger relationship for the physical domain. PA duration showed a direct-trend relationship with QoL, but the associations were stronger for MVPA in both studies. However, when stratified by health status, the magnitude of the association between "walking" duration and a higher physical QoL was greater among those at risk or with CVD compared to 'healthy' individuals. Conversely, among Australians with CVD, MVPA was associated with a better physical QoL only when its duration was ≥150 min/week. All associations were stronger in the NWAHS than in the Brazilian study. CONCLUSIONS: "Walking" was more prevalent than MVPA and was consistently associated with a better physical QoL among those at risk or with CVD. These findings should be considered in the design of public health interventions designed to increase PA and improve QoL.

Tooth loss and general quality of life in dentate adults from Southern Brazil.

PURPOSE: This study aimed to estimate the association between the number of teeth and general quality of life in adults. METHODS: A population-based study was conducted with 1720 individuals aged 20-59 years residing in Florianópolis, Brazil, in 2009. Data were collected at participants' households using a structured questionnaire. In 2012, a second wave was undertaken with 1222 individuals. Oral examinations were performed for number of teeth, prevalence of functional dentition (≥21 natural teeth), and shortened dental arch (SDA), which were considered the main exposures. General quality of life was the outcome and was assessed with the WHO Abbreviated Instrument for Quality of Life (WHOQOL-BREF). Covariates included sociodemographic factors, health-related behaviors, and chronic diseases. Multivariable linear regression models were performed to test the associations between the main exposures and the outcome adjusted for covariates. RESULTS: In 2012, 1222 individuals participated in the study (response rate = 71.1%). Having more teeth was associated with greater scores on physical domain of the WHOQOL-BREF [ß = 0.24 (95% CI 0.01; 0.46)] after adjustment for covariates. Absence of functional dentition was associated with lower scores on the physical domain [ß = -3.94 (95% CI -7.40; -0.48)] in the adjusted analysis. There was no association between both SDA definitions and the domains of general quality of life. CONCLUSIONS: Oral health as measured by tooth loss was associated with negative impacts on general quality of life assessed by the WHOQOL-BREF. There was a lack of evidence that SDA is a condition that negatively affects general quality of life.