Determining the most appropriate socioeconomic status indicator for describing inequalities in dental visits by Japanese older people.

OBJECTIVES: This study examined the association between various socioeconomic status (SES) indicators and dental visits among older Japanese. BACKGROUND: When examining health inequalities, an adequate indicator of SES should be applied. In older adults, wealth and pensions are considered more appropriate indicators of SES than education and income, but few studies have examined. METHODS: This cross-sectional study used data from 12 391 individuals aged 65 years or older from the 2016 Japan Gerontological Evaluation Study (JAGES). The Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) were applied to examine the association of education, income, wealth and pensions with dental visits for treatment and check-up adjusting for covariates. RESULTS: The mean age of the participants was 74.0 ± 6.2 years. In the previous year, 56.3% of participants had visited a dentist for a check-up, and 65.9% had visited for treatment. Inequalities in dental treatment visits were observed for wealth, pensions and income rather than education. Income was not significantly associated with check-up visits. Wealth showed the largest association with dental visits for treatment [(SII 0.09, 95% CI 0.06 to 0.13), (RII 1.14, 95% CI 1.09 to 1.21)] and check-up [(SII 0.08, 95% CI 0.05 to 0.12), (RII 1.16, 95% CI 1.09 to 1.23)]. CONCLUSION: When measuring inequalities in access to dental care among the older population, wealth and pensions could be important indicators of SES.

Does Tobacco Smoking Increase Social Isolation? A Mendelian Randomization Study.

In this study, we aimed to investigate the causal effect of smoking on social isolation among older adults in England. Data from older adults of European ancestry who participated in 1 or more waves of the English Longitudinal Study of Ageing, from wave 1 (2002/2003) to wave 9 (2018/2019), were analyzed (n = 43,687 observations from 7,008 individuals; mean age = 68.50 years). The effect of current smoking on social isolation (ranging from 0 to 5) was estimated by 2-stage least squares regression using a polygenic score (PGS) for smoking cessation as the instrument. A low PGS for smoking cessation predicted current smoking (per 1-standard-deviation lower PGS, coefficient = 0.023, 95% confidence interval (CI): 0.015, 0.030; F = 36.420). The second-stage regression showed that current smoking increased social isolation by 1.205 points (95% CI: 0.308, 2.101). The association was larger for persons with higher socioeconomic backgrounds: 2.501 (95% CI: -0.024, 5.026) and 0.696 (95% CI: -0.294, 1.686) for those with higher and lower educational levels, respectively. This study showed that current smoking instrumented by a PGS for smoking cessation was associated with social isolation. Assuming that the PGS served as a valid instrument in this study, the findings support an effect of smoking on social isolation.

COVID-19 severity is associated with the risk of gastrointestinal bleeding.

OBJECTIVE: The association between the severity of COVID-19 and gastrointestinal (GI) bleeding is unknown. This study aimed to determine whether the severity of COVID-19 is a risk factor for GI bleeding. DESIGN: A multicentre, retrospective cohort study was conducted on hospitalised patients with COVID-19 between January 2020 and December 2021. The severity of COVID-19 was classified according to the National Institute of Health severity classification. The primary outcome was the occurrence of GI bleeding during hospitalisation. The main analysis compared the relationship between the severity of COVID-19 and the occurrence of GI bleeding. Multivariable logistic regression analysis was performed to evaluate the association between the severity of COVID-19 and the occurrence of GI bleeding. RESULTS: 12 044 patients were included. 4165 (34.6%) and 1257 (10.4%) patients had severe and critical COVID-19, respectively, and 55 (0.5%) experienced GI bleeding. Multivariable analysis showed that patients with severe COVID-19 had a significantly higher risk of GI bleeding than patients with non-severe COVID-19 (OR: 3.013, 95% CI: 1.222 to 7.427). Patients with critical COVID-19 also had a significantly higher risk of GI bleeding (OR: 15.632, 95% CI: 6.581 to 37.130). Patients with severe COVID-19 had a significantly increased risk of lower GI bleeding (OR: 10.349, 95% CI: 1.253 to 85.463), but the risk of upper GI bleeding was unchanged (OR: 1.875, 95% CI: 0.658 to 5.342). CONCLUSION: The severity of COVID-19 is associated with GI bleeding, and especially lower GI bleeding was associated with the severity of COVID-19. Patients with severe or critical COVID-19 should be treated with caution as they are at higher risk for GI bleeding.

Association between the number of convenience stores and caries status in permanent teeth among elementary school children: results from the A-CHILD population-based longitudinal cohort study.

Background: In Japan, people have rich access to 24-h convenience stores where they can buy sweets, juice and fluoride hygiene products, among others. However, the association between the number of convenience stores in a neighbourhood and caries in elementary school children status has not been studied. This study aimed to investigate this particular association. Methods: Data were derived from a population-based longitudinal cohort study (A-CHILD study) of elementary school children from first-grade to fourth-grade in Adachi City, Tokyo. Caregivers were asked to complete a questionnaire in 2015, 2016, and 2018. A total of 3,136 caregivers provided a valid response. We analysed the association using multilevel Poisson regression. Results: The mean number of caries among children in school districts with low, middle, and high number of convenience stores was 0.31 (SD: 0.81), 0.21 (SD: 0.69), and 0.16 (SD: 0.58). After covariate adjustment, children in the school districts with high and middle number of convenience stores had 44% (mean ratio 0.56, 95% CI: 0.31, 0.998) and 31% (mean ratio 0.69, 95% CI: 0.42, 1.13) fewer caries in their permanent teeth, respectively, than children in the school districts with low number of convenience stores. We also found dose-response relationship (p for trend: 0.042). Conclusion: Higher number of convenience stores in a school district was associated with fewer caries in permanent teeth among elementary school children. Further study elucidating the mechanism on this protective association is warranted.

Tongue Strength of Older Adults Requiring Long-Term Care Varies throughout the Day.

Physical performance shows approximately 30% diurnal variation; however, diurnal variation in oral function remains unclear. This study aimed to determine the diurnal variation in oral and swallowing function in older adults requiring long-term care. The participants included 13 adults aged >60 years (3 men and 10 women, mean age: 77.2 ± 6.3 years, age range: 62-90 years) requiring long-term care. Tongue strength (TS) and oral mucosal moisture were measured as indices of oral and swallowing function, while hand grip strength was measured as an index of general muscle strength. The patients were asked to participate in a "test" after breakfast, lunch, and dinner on the same day. Multilevel linear regression analysis was used to examine diurnal differences in each item. Multilevel linear regression analysis with adjustment for age and sex revealed that TS was significantly higher at noon (p = 0.001) than in the morning. Therefore, caregivers who provide support during meals to older people requiring long-term care should consider the possibility of swallowing function differing according to the time of the day. In conclusion, it may be beneficial to establish a nutritional therapy that accounts for the diurnal variation in TS.

Malnutrition- inflammation- atherosclerosis (MIA) syndrome associates with periodontitis in end-stage renal disease patients undergoing hemodialysis: a cross-sectional study.

Malnutrition-inflammation-atherosclerosis (MIA) syndrome is a significant risk factor for mortality in patients undergoing hemodialysis. This study aimed to investigate the association between MIA syndrome and oral health status in hemodialysis patients. A cross-sectional study was conducted on 254 hemodialysis patients. Comprehensive medical and dental examinations were performed. Three components were included to define MIA syndrome: Geriatric Nutritional Risk Index, serum high-sensitivity C-reactive protein, and history of cardiovascular events as indicators of malnutrition, inflammation, and atherosclerosis, respectively. The association of MIA syndrome components with periodontitis and occlusal support was examined by multiple-ordered logistic regression analysis. Of 254 participants, 188 (74.0%) had at least one component of MIA syndrome. After adjusting for possible confounding factors, severe periodontitis was significantly associated with presence of more components of MIA syndrome (odds ratio [OR]: 2.64, 95% confidence interval [CI], 1.44-4.84, p = 0.002) and inflammation and malnutrition components (OR: 2.47 and 3.46, 95% CI 1.16-5.28 and 1.70-7.05, p = 0.020 and 0.001). On the other hand, occlusal support, evaluated by Eichner index, was not significantly associated with MIA syndrome or any of its components. In conclusion, periodontitis is associated with MIA syndrome, particularly with inflammation and malnutrition in hemodialysis patients, independent of occlusal support.

Association between adverse childhood experiences and marital status among Japanese older adults.

BACKGROUND: Marital status is a well-known social determinant of health. Adverse childhood experiences (ACEs) affect attachment, critical to establishing and maintaining intimate relationships, such as marital status. OBJECTIVE: This study examined the association between ACEs and marital status among older Japanese adults. PARTICIPANTS AND SETTING: This research used data from a nationwide population-based study among functionally independent people aged 65 and above in Japan. METHODS: ACEs were assessed by self-reported questionnaires on the following experiences before 18 years old: parental death, parental divorce, parental mental disease, exposure to intimate partner violence, physical abuse, psychological neglect, psychological abuse, and poverty. Marital status was asked as currently having a spouse (including common-law marriage), widowed, divorced, or unmarried. Associations between the total number of ACEs and marital status were analyzed by multinomial logistic regression. RESULTS: Three or more ACEs showed higher risks of being widowed, divorced, or unmarried. Psychological neglect led to higher divorce risks among males (RRR, 95%CI = 1.41, 1.13-1.76) and females (RRR, 95%CI = 1.56, 1.28-1.89). Childhood poverty showed higher risks of unmarried among males (RRR, 95%CI = 1.25, 1.02-1.53) and females (RRR, 95%CI = 1.41, 1.18-1.69). Association between ACEs and divorce risks showed gender differences (RRR, 95%CI of having three or more ACEs in males: 2.19, 1.66-2.90; in females: 3.45, 2.71-4.38; p for interaction = 0.034). CONCLUSIONS: ACEs showed higher risks of being widowed, divorced, and unmarried among older Japanese people. Policy to tackle ACEs and research investigating how ACEs, attachment, and relationship quality influence marital status are required to promote well-being in later life.

Persistent poverty and child dental caries: time-varying exposure analysis.

BACKGROUND: This study investigated the cumulative impact of persistent poverty on dental caries among elementary schoolchildren in Japan. METHODS: Data were derived from four-wave longitudinal data of children in all public elementary schools in Adachi City, Tokyo, Japan, from 2015 to 2020 (n=4291, response rate: 80.1%-83.8%). Poverty status, defined as annual household income

Change of human flourishing during the COVID-19 pandemic in Japan: Results from population-based U-CORONA study.

Longitudinal change in flourishing during the pandemic of COVID-19 would provide new insight to reveal determinants of well-being. We aimed to describe changes in flourishing during the COVID-19 pandemic in Japan and to examine the association of sex, age, education, and income with changes in flourishing. Utsunomiya COVID-19 seROprevalence Neighborhood Association (U-CORONA) study conducted in October 2020 and November 2021 was used (n = 419 in 2020 and n = 478 in 2021, and n = 327 for both waves). Flourishing was assessed using a 12-item multidimensional flourishing scale including six domains. Change of flourishing was categorized into decreased, unchanged, and increased. Multinomial logistic regression was applied to longitudinal data to estimate the relative risk ratio of increase and decrease in flourishing scores. Cross-sectional analysis showed that the mean score of flourishing was approximately seven in both waves, with no sex differences, but older adults had higher scores than young-aged adults. We found that men were twice as likely to lose their flourishing scores as women and lower levels of education were associated with 2-3 times declining flourishing scores than higher levels of education. Age and income were not significantly associated with the change of flourishing. During the COVID-19 pandemic, flourishing declined, and men and lower-educated people were more vulnerable. In prolonged difficult situations, support for men and less educated people may contribute to the prevention of declining well-being in Japan.

Peritoneal closure and the processus vaginalis transection method to prevent inguinal hernia after robot-assisted radical prostatectomy.

OBJECTIVES: Postoperative inguinal hernia (IH) is one of the most common complications of radical prostatectomy (RP) including robot-assisted RP (RARP). However, a procedure to prevent IH after RARP has not been established. We investigated the impact of processus vaginalis transection (PVT) and PVT with peritoneal closure on IH after RARP. METHODS: A retrospective analysis was performed on data from patients who underwent RARP at two tertiary hospitals in Japan, where PVT with subsequent peritoneal closure was introduced after 2014. The incidence of IH for 2 years after RARP was compared among 79 patients without PVT or peritoneal closure, 232 patients with only PVT, and 325 patients with PVT and peritoneal closure. Multivariable Cox proportional hazard models that adjusted for hospital, age, history of abdominal operation, body mass index, operation time, and prostate weight were used. RESULTS: Postoperative IH was observed in seven (8.9%) patients without PVT or peritoneal closure, 34 (15%) patients with only PVT, and nine (2.8%) patients with PVT and peritoneal closure. Compared with patients without PVT or peritoneal closure, the incidence of IH was not different in patients with only PVT (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.34, 2.38) and significantly lower in patients with PVT and peritoneal closure (HR 0.22, 95% CI 0.07, 0.70). CONCLUSION: PVT with peritoneal closure may reduce the risk of postoperative IH after RARP. Future randomized controlled trials are required to confirm these findings.

Phenylephrine-Induced Contraction in Guinea Pig Thoracic Aorta Is Triggered by Stimulation of α1L-Adrenoceptors Functionally Coupled with Store-Operated Ca2+ Channels and Voltage-Dependent Ca2+ Channels.

We examined whether the α1L-adrenoceptor (AR), which shows low affinity (pA2 < 9) for prazosin (an α1-AR antagonist) and high affinity (pA2 ≈ 10) for tamsulosin/silodosin (α1A-AR antagonists), is involved in phenylephrine-induced contractions in the guinea pig (GP) thoracic aorta (TA). Intracellular signaling induced by α1L-AR activation was also examined by focusing on Ca2+ influx pathways. Tension changes of endothelium-denuded TAs were isometrically recorded and mRNA encoding α-ARs/Ca2+ channels and their related molecules were measured using RT-quantitative PCR. Phenylephrine-induced contractions were competitively inhibited by prazosin/tamsulosin, and their pA2 value were calculated to be 8.53/9.74, respectively. These contractions were also inhibited by silodosin concentration-dependently. However, the inhibition was not competitive fashion with the apparent pA2 value being 9.48. In contrast, phenylephrine-induced contractions were not substantially suppressed by L-765314 (an α1B-AR antagonist), BMY 7378 (an α1D-AR antagonist), yohimbine, and idazoxan (α2-AR antagonists). Phenylephrine-induced contractions were markedly inhibited by YM-254890 (a Gq protein inhibitor) or removal of extracellular Ca2+, and partially inhibited by verapamil (a voltage-dependent Ca2+ channel (VDCC) inhibitor). The residual contractions in the presence of verapamil were slightly inhibited by LOE 908 (a receptor-operated Ca2+ channel (ROCC) inhibitor) and strongly inhibited by SKF-96365 (a store-operated Ca2+ channel (SOCC) and ROCC inhibitor). Among the mRNA encoding α-ARs/SOCC-related molecules, α1A-AR (Adra1a)/Orai3, Orai1, and Stim2 were abundant in this tissue. In conclusion, phenylephrine-induced contractions in the GP TA can be triggered by stimulation of Gq protein-coupled α1L-AR, followed by activation of SOCCs and VDCCs.

Tap water natural fluoride and parent-reported experience of child dental caries in Japan: Evidence from a nationwide birth cohort survey.

INTRODUCTION: Water fluoridation is an effective measure to prevent dental caries. In Japan, artificial water fluoridation is not implemented, and tap water natural fluoride concentration geographically differs because of various soil natures. This study aimed to examine the association between tap water natural fluoride and parent-reported experience of dental caries in children. METHOD: Data from the Longitudinal Survey of Newborns in the twenty-first century, a national birth cohort study following all infants born between January 10-17 and July 10-17, 2001, were analysed. Caregivers answered the child's caries treatment history, a proxy for dental caries, yearly from 5.5 to 12 years of age (N = 202 517 observations from 34 998 children). The annual data on tap water natural fluoride concentration in the municipality of residence were obtained from the national statistics. Cross-classified multilevel Poisson regression models were fitted, adjusting for child, household and municipality characteristics, including average income and dental clinic density. RESULTS: The average tap water natural fluoride concentration across municipalities was 0.0887 ppm (SD = 0.0422). The proportion of parent-reported experience of child dental caries treatment ranged from 24.9% (at 12 years) to 40.3% (at 7 years) and was lower among children living in municipalities with high natural fluoride concentrations, which were 35.0%, 35.4%, 33.4% and 32.3% for <0.10, 0.10-0.19, 0.20-0.29 and ≥0.30 ppm respectively. A 0.1 ppm increment in tap water natural fluoride after controlling for all covariates was significantly associated with a lower prevalence of parent-reported child dental caries treatment by 3.3% (prevalence ratio = 0.967, 95% credible interval: 0.939, 0.996). CONCLUSION: Natural fluoride in tap water showed a protective effect for the parent-reported experience of child dental caries in Japan.

"What Did You Do in the War, Daddy?": Paternal Military Conscription During WWII, Economic Hardship and Family Violence in Childhood, and Health in Late Life in Japan.

Childhood adversity is a risk factor for poor health in late life and includes economic hardship and family violence, whose prevalence is high among offspring of military conscripted father. We assessed the association between paternal military conscription (PMC) and paternal war death (PWD) during Second World War and self-rated health (SRH) among older adults in Japan. Data were obtained from a population-based cohort of functionally independent people aged 65 years or older from 39 municipalities across Japan in 2016. Information on PMC and SRH was obtained through a self-report questionnaire. A total of 20,286 participants were analyzed with multivariate logistic regression to investigate the association between PMC, PWD, and poor health. Causal mediation analysis was performed to see whether childhood economic hardship and family violence mediated the association. Among participants, 19.7% reported PMC (including 3.3% PWD). In the age- and sex-adjusted model, older people with PMC showed higher risk of poor health (odds ratio [OR]: 1.16, 95% confidence interval [CI] [1.06, 1.28]), while those with PWD were not associated (OR: 0.96, 95% CI [0.77, 1.20]). Causal mediation showed a mediation effect of childhood family violence exposure on the association between PMC and poor health (proportion mediated: 6.9%). Economic hardship did not mediate the association. PMC, but not PWD, increased the risk of poor health in older age, which was partially explained by the exposure to family violence in childhood. There appears to be a transgenerational health impact of war which continues to affect the health of offspring as they age.

Time-varying exposure analysis of the relationship between sustained natural dentition and cognitive decline.

AIM: Tooth loss and cognitive decline progress over time and influence each other. This study estimated the impact of sustaining natural dentition on cognitive function in U.S. adults, accounting for the fact that dental and cognitive statuses change over time. MATERIALS AND METHODS: Data from adults aged ≥51 years who participated in five waves of the Health and Retirement Study from 2004 to 2016 (n = 10,953) were analysed. The impact of retaining some natural teeth from 2006 to 2012 on cognitive function score (0-27) and cognitive impairment (defined as having a cognitive function score of <12) in 2016 was evaluated using the doubly robust targeted maximum likelihood estimation method by considering both time-invariant and time-varying confounders, including cognitive function at baseline and during follow-up. RESULTS: Respondents with some natural teeth between 2006 and 2012 had a 0.40 point (95% confidence interval [CI]: 0.10-0.71) higher cognitive function score and 3.27 percentage point (95% CI: 0.11-6.66) lower cognitive impairment prevalence in 2016 than those with complete tooth loss. CONCLUSIONS: Considering past cognitive function assessed at multiple time points, sustained natural dentition was associated with better cognitive function.

Stepwise Tobacco Price Increase and Smoking Behavioral Changes in Japan: The Japan "Society and New Tobacco" Internet Survey 2017-2021 Longitudinal Study.

INTRODUCTION: Tobacco price increase is an effective measure to reduce tobacco smoking. In Japan, the price of combustible cigarettes increased in 2018 and 2020, and that of heated tobacco products increased every year from 2018 to 2020 by tobacco excise taxation. Also, the general consumption tax increase in 2019 slightly raised the retail prices of tobacco products. We investigated the impact of this stepwise tobacco price increase on combustible cigarette smoking status among Japanese adults. AIMS AND METHODS: Five waves of annual longitudinal data (2017-2021) from The Japan "Society and New Tobacco" Internet Survey (JASTIS) (31 930 observations of 11 896 individuals) were analyzed. Multivariable logistic regression with a generalized estimating equation was fitted, adjusting for the prefecture of residence, age, sex, socioeconomic status, health status, alcohol drinking, former smoker's duration of smoking cessation, and the current smoker's number of cigarettes smoked per day. RESULTS: The 2018 price increase was associated with a reduction in relapse (adjusted odds ratio [aOR] 0.54, 95% confidence interval [CI] 0.42-0.68) and an increment in cessation (aOR 1.20, 95% CI 1.02-1.42). The price increase in 2019 was not associated with relapse (aOR 0.84, 95% CI 0.63-1.10) or cessation (aOR 0.95, 95% CI 0.80-1.13). The 2020 price increase was associated with a reduction in relapse (aOR 0.59, 95% CI 0.42-0.81) and an increment in cessation (aOR 1.45, 95% CI-1.21, 1.73). CONCLUSION: The price increase caused by tobacco excise taxation was associated with a reduction in combustible cigarette smoking. IMPLICATIONS: Japan introduced a policy of stepwise increase in tobacco excise taxation in 2018. We analyzed five-wave longitudinal data to investigate the impact of the policy. Tobacco price increases in 2018 and 2020 were associated with a reduction in combustible cigarette smoking. Tobacco price increases in 2019 by general consumption tax were not associated with a change in combustible cigarette smoking.

A cross-sectional study evaluating patients' preferences for Salter innominate osteotomy.

BACKGROUND: Residual acetabular dysplasia in children after reduction of hip dislocation is often treated using Salter innominate osteotomy to prevent future osteoarthritis. Preventive surgery for asymptomatic patients, which could result in overtreatment, should be carefully applied with consideration of patients' opinions. In this study, we aimed to describe opinions on Salter innominate osteotomy as preventive surgery for children among adult patients who had undergone periacetabular osteotomy for hip pain due to hip dysplasia. METHODS: A mail-in questionnaire survey was conducted with 77 patients who underwent periacetabular osteotomy. Participants responded whether they would recommend Salter innominate osteotomy as preventive surgery for children and the reason for their opinion. We also performed a patient-based evaluation using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire and assessed clinical outcome measures with the Japanese Orthopedic Association score. Their recommendations and reasons were evaluated, and associations between their opinions and demographic and clinical characteristics were analyzed. RESULTS: Forty-three patients (56%) responded to the questionnaire. Of these, 10 (23%) patients recommended undergoing Salter innominate osteotomy, 28 (65%) patients did not, and 5 (12%) patients responded they were undecided. No significant association was observed between their opinions and demographic/clinical characteristics evaluated in the survey. The most frequent reason for why they do not recommend Salter innominate osteotomy was related to uncertainty about future hip pain. CONCLUSIONS: In total, 65% of the study participants did not recommend Salter innominate osteotomy for children with risk of dysplasia in the future. Participants' preferences regarding preventive surgery were not influenced by demographic and clinical characteristics.

Duration of Education and Back Pain: Lessons From English Schooling Reforms.

This study aimed to examine the associations of increases in the duration of education with back pain using the exogenous variation generated by the English schooling reforms of 1947 and 1972. We analyzed cross-sectional data derived from 9 waves (waves 1-9; 2002-2019) of the English Longitudinal Study of Ageing. An instrumental variables regression using 2-stage least squares with the 2-way cluster-robust standard error was used. The mean severity of back pain, measured using the Numerical Rating Scale, was used as the outcome. A total of 22,868 observations from 5,070 participants were included (the 1947 reform = 16,565 observations from 3,231 participants, mean age = 74.5 years; the 1972 reform = 6,303 observations from 1,839 participants, mean age = 59.3 years). The schooling reforms significantly extended years of school attendance by a mean of 0.57 years for the 1942 reform cohort and 0.66 years for 1972 reform cohort. For participants born within 5 years of the pivotal cohorts, an additional year of education decreased the severity of back pain by 0.78 points (95% confidence interval: 0.65, 0.92) for the 1972 reform cohort. Our finding underscores the importance of the length of education in the reduction of back pain in middle-aged individuals.

Being Left Alone at Home and Dental Caries of Children Aged 6-7 Years.

BACKGROUND: Leaving children alone at home is considered child neglect in some countries but is not prohibited in Japan. We investigated the association between being left alone at home and dental caries of children aged 6-7 years in Japan. METHODS: The data on first graders in all 69 public elementary schools in Adachi, Tokyo, obtained from repeated cross-sectional surveys in 2015, 2017, and 2019 were analyzed. Caregivers answered the questionnaire, and the data were linked to the information on children's dental caries evaluated in school dental health checkups (N = 12,029). Poisson regression analysis with propensity score matching (PSM) was applied to account for confounders. RESULTS: Leaving children alone at home for ≥1 hour during the weekdays was reported by 46.4% of the caregivers, which did not vary across years. The PSM analysis showed that, compared with children never being left alone at home, children being left alone at home for ≥1 time per week had more dental caries (mean ratio [MR] 1.11; 95% confidence interval (CI), 1.02-1.21; P = 0.016), while <1 time per week was not associated (MR 0.97; 95% CI, 0.92-1.03; P = 0.345). The difference between those being left alone at home for <1 time per week and those being left alone for ≥1 time per week was not significant after applying Bonferroni correction (MR 1.12; 95% CI, 1.00-1.26; P = 0.041). CONCLUSION: Leaving children alone at home for ≥1 hour every week might be a risk factor for dental caries of children aged 6-7 years.

Impacts of the COVID-19 Pandemic Exposure on Child Dental Caries: Difference-in-Differences Analysis.

The impact of the coronavirus disease 2019 (COVID-19) pandemic on dental caries is unknown. We investigated the effect of the pandemic on child dental caries in Japan by comparing the increase in dental caries from fourth to sixth grade between two cohorts, COVID-19 exposed cohort and COVID-19 unexposed cohort, using difference-in-differences analysis. Longitudinal data that followed elementary school children in Adachi City, Tokyo, were analyzed. The analysis consisted of two cohorts: those who were in fourth grade in 2016 and sixth grade in 2018 (COVID-19 unexposed cohort, N = 399) and those who were in fourth grade in 2018 and sixth grade in 2020 (COVID-19 exposed cohort, N = 3,082). Children's dental caries were examined by school dentists. A difference-in-differences analysis, adjusting for time-variant variables, i.e., household socioeconomic status, children's oral health behavior, and caregivers' psychological distress, was performed. In fourth grade, the number of Decayed, Missing, and Filled permanent Teeth (DMFT) was not different between the COVID-19 unexposed and exposed cohorts (mean = 0.241 and 0.242, respectively). In sixth grade, DMFT increased by 0.067 in the COVID-19 unexposed cohort and 0.180 in the COVID-19 exposed cohort. The interaction term of grade and cohorts for caries by difference-in-differences analysis showed that dental caries among the COVID-19 exposed cohort showed a significant increase in the number of dental caries by 0.116 (95% confidence interval 0.015, 0.216) compared to the COVID-19 unexposed cohort. Child dental caries slightly increased after the pandemic. Studies with longer follow-ups are needed to evaluate the impact of the pandemic on child dental caries.

Association between social capital and COVID-19 preventive behaviors: Country-level ecological study.

Background: The association between social capital and preventive behaviors against COVID-19 remains controversial. We examined the association between social capital and preventive behaviors against COVID-19 at country level. Methods: The data on country-level social capital (i.e., social trust, group affiliations, civic responsibility, and confidence in state institutions) was obtained from a previous literature based on World Value Survey. Preventive behaviors were calculated as the percentage of people in a country who took COVID-19 preventive behaviors (i.e., physical distancing, hand hygiene, and the use of face mask) from an international survey of Facebook users, from July to October 2020 (207 data points for 9 waves of 23 countries). The scores on social capital were standardized. The association was investigated with multilevel linear regression analysis. Results: High civic responsibility (per 1 standard deviation, SD) was associated with low percentage points of physical distancing (ß = -4.66, 95% confidence interval, CI: 7.23, -2.09), hand hygiene (ß = -2.88, 95% CI: 3.98, -1.78) and the use of face mask (ß = -3.95, 95% CI: 5.29, -2.62). Group affiliations were associated with high percentage points of physical distancing (ß = 2.96, 95% CI: 0.35, 5.58) and the use of face mask (ß = 1.80, 95% CI: 0.45, 3.16). Social trust had significant positive association with performing hand hygiene (ß = 1.22, 95% CI: 0.09, 2.35). Conclusions: These results suggested that in countries with higher levels of civic responsibility, preventive behaviors should be more intensified during a pandemic.