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Two frequently encountered but underrecognized challenges for causal inference in studying the long-term health effects of disasters among survivors include 1) time-varying effects of disasters on a time-to-event outcome and 2) selection bias due to selective attrition. In this paper, we review approaches for overcoming these challenges and demonstrate application of the approaches to a real-world longitudinal data set of older adults who were directly affected by the 2011 Great East Japan Earthquake and Tsunami (n = 4,857). To illustrate the problem of time-varying effects of disasters, we examined the association between degree of damage due to the tsunami and all-cause mortality. We compared results from Cox regression analysis assuming proportional hazards with those derived using adjusted parametric survival curves allowing for time-varying hazard ratios. To illustrate the problem of selection bias, we examined the association between proximity to the coast (a proxy for housing damage from the tsunami) and depressive symptoms. We corrected for selection bias due to attrition in the 2 postdisaster follow-up surveys (conducted in 2013 and 2016) using multivariable adjustment, inverse probability of censoring weighting, and survivor average causal effect estimation. Our results demonstrate that analytical approaches which ignore time-varying effects on mortality and selection bias due to selective attrition may underestimate the long-term health effects of disasters.

Background: Local anaesthesia in dental procedures is generally safe, although the occurrence of transient bradycardia (TB) has occasionally been reported. TB is often associated with two reflexes, the trigeminal cardiac reflex (TCR) and the vasovagal reflex (VVR) and is characterised by a rapid decrease in heart rate (HR) and blood pressure (BP). The prevalence of TCR is considered low, and its predictors have not been thoroughly investigated, although an association with the gag reflex has been suggested in recent years. Methods: This prospective study assessed TB occurrence during local anaesthesia and its potential associated factors. A comprehensive questionnaire was used to categorise discomforts during dental treatment, and various anxiety scales were used to measure patients' anxiety levels. We investigated HR variability during local anaesthesia administration under sedation and the association between the incidence of TB and gag reflex. Subsequently, logistic regression analysis was performed to assess factors associated with TB occurrence. Results: The prospective analysis included 188 patients of 234 initial patients. The analysis revealed a high TB incidence rate of 41% during local anaesthesia administration under sedation. No severe hypotensive events occurred, indicating a relatively benign nature of TB during local anaesthesia. TB occurrence was significantly higher in the group of patients with the gag reflex. Further analysis revealed that both gag reflex and trait anxiety were significantly associated with TB occurrence, whereas dental phobia did not directly correlate with TB. Conclusion: This study highlights the prominent occurrence of TB during local anaesthesia in dental treatment, which is primarily attributed to TCR activation. The identification of gag reflex and trait anxiety as independent factors associated with TB development may pave the way for TB prevention measures. Further research is required to clarify the mechanisms of TCR and perform safer dental procedures under sedation. Future studies should also aim to elucidate the precise mechanisms underlying TB during local anaesthesia through direct measurements of neural activity. A better understanding of TB in dentistry is crucial for improving patient safety and optimising dental practice protocols. [ABSTRACT FROM AUTHOR]

Background: There have been limited studies with statistically sufficient sample sizes for assessment of suitable bone defect morphology for combination therapy with enamel matrix derivative (EMD) and bone grafting. The aim of this study was to investigate the appropriate feature of intrabony defects, such as bone defect angle (DA) and the containment by bony wall, for yielding the additional benefit of bone grafting in combination with periodontal regenerative therapy using EMD. Methods: Following periodontal regenerative therapy using EMD with or without autologous bone grafting, 282 intrabony defects of 177 participants were maintained for 3 years. Multilevel linear regression analysis was performed to evaluate the radiographic bony defect depth (RBD) reduction after adjusting for confounders. Results: The baseline parameters, except for the proportion of contained bony defects and tooth mobility, did not differ significantly between the groups with and without bone grafts. There was no significant difference in the improvement of clinical parameters between the groups. The 1‐ and 3‐year reduction of RBD showed significant inverse correlations with preoperative DA only in the group without bone graft. Furthermore, multivariate analysis showed a significant interaction between DA at baseline ≥40° and adjunctive bone grafting in the reduction of RBD, regardless of the number of bony walls. Conclusion: Adjunctive autologous bone grafting with enamel matrix derivative might be significantly beneficial for defect depth improvement in the case of DA at baseline ≥40°. [ABSTRACT FROM AUTHOR]

Background Long-term care (LTC) costs create burdens on aging societies. Maintaining oral health through dental visits may result in shorter LTC periods, thereby decreasing LTC costs; however, this remains unverified. We examined whether dental visits in the past 6 months were associated with cumulative LTC insurance (LTCI) costs. Methods This cohort study of the Japan Gerontological Evaluation Study targeted independent adults aged≥65 years in 2010 over an 8-year follow-up. We used data from a self-reported questionnaire and LTCI records from the municipalities. The outcome was cumulative LTCI costs, and exposure was dental visits within 6 months for prevention, treatment, and prevention or treatment. A 2-part model was used to estimate the differences in the predicted cumulative LTCI costs and 95% confidence intervals (CIs) for each dental visit. Results The mean age of the 8 429 participants was 73.7 years (standard deviation [ SD ] = 6.0), and 46.1% were men. During the follow-up period, 17.6% started using LTCI services. The mean cumulative LTCI cost was USD 4 877.0 (SD  = 19 082.1). The predicted cumulative LTCI costs were lower among those had dental visits than among those who did not. The differences in predicted cumulative LTCI cost were −USD 1 089.9 (95% CI = −1 888.5 to −291.2) for dental preventive visits, −USD 806.7 (95% CI = −1 647.4 to 34.0) for treatment visits, and −USD 980.6 (95% CI = −1 835.7 to −125.5) for preventive or treatment visits. Conclusions Dental visits, particularly preventive visits, were associated with lower cumulative LTCI costs. Maintaining oral health through dental visits may effectively reduce LTCI costs. [ABSTRACT FROM AUTHOR]

Purpose: A growing body of evidence suggests that oral health is associated with a wide range of health outcomes; however, opinions tend to vary because of inconsistent findings. This study aimed to simultaneously examine the association between oral health status and multiple health and well-being indicators using outcome-wide epidemiology. Methods: Data were obtained from the Japan Gerontological Evaluation Study. Oral health status was categorized as: ≥20 teeth, 10-19 teeth with dental prosthesis, 0-9 teeth with prosthesis, 10-19 teeth without prosthesis, and 0-9 teeth without prosthesis. We examined the associations between oral health status in 2013 and 35 health and well-being outcomes in 2019, including physical/cognitive health, psychological distress, subjective health, social well-being, prosocial/altruistic behaviors, and health behaviors, using two databases (n=32,827 and 15,905). Results: Compared to individuals with ≥20 teeth, those with <20 teeth had a 10-33% higher risk of mortality and a 6-14% higher risk of functional disability six years later. Additionally, individuals with fewer than 20 teeth tended to go out less frequently and eat fewer vegetables and fruits. Furthermore, individuals with 0-9 teeth without a prosthesis were more likely to have severe functional disability (risk ratio (RR):1.17, 95% confidence interval (CI):1.05-1.31), engage in fewer intellectual activities (standardized difference: 0.17, 95% CI: 0.10-0.24), and feel more hopeless (RR: 1.21, 95% CI: 1.04-1.41). Conclusions: The prevention of tooth loss and prosthodontic treatment may be associated with reduced mortality and functional disability, as well as maintenance of intellectual ability, frequency of going out, and improvements in dietary lifestyle. [ABSTRACT FROM AUTHOR]

Objective This study aimed to determine whether the frequency of eating together is associated with the incidence of functional disability in older adults who live alone. Methods This 6-year observational prospective cohort study utilised self-reported questionnaires. Data were drawn from the participants of the Japan Gerontological Evaluation Study project between 2016 and 2022. The participants were independent older adults aged ≥65 years living alone in Japan. The primary outcome was the incidence of functional disability during the follow-up period, with the self-reported frequency of eating together serving as the explanatory variable. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models after adjusting for confounders associated with incident functional disability. Results Among the 7167 participants, the mean age at baseline was 75.3 ± 6.5 years and 69.2% were female. About, 12.8% of participants (n  = 917) developed functional disabilities during the observation period. The incidence rates were 11.7% for 'every day', 11.3% for 'several times a week', 11.5% for 'several times a month', 12.7% for 'several times a year' and 19.0% for 'seldom'. The frequency of eating together 'seldom' was significantly associated with an increased incidence of functional disability (HR: 1.55, 95% CI: 1.10–2.18). Conclusion Among older adults living alone, infrequent eating together ('seldom') was identified as a risk factor for developing functional disability. [ABSTRACT FROM AUTHOR]