Bivalent mRNA vaccine effectiveness against COVID-19 among older adults in Japan: a test-negative study from the VENUS study.

BACKGROUND: Bivalent COVID-19 vaccines have been implemented worldwide since the booster vaccination campaigns of autumn of 2022, but little is known about their effectiveness. Thus, this study holistically evaluated the effectiveness of bivalent vaccines against infection in older adults in Japan. METHODS: We adopted the test-negative design using COVID-19 test data of individuals, aged ≥ 65 years, residing in three municipalities in Japan, who underwent tests in medical institutions between October 1 and December 30, 2022. Logistic regression analyses were conducted to estimate the odds of testing positive according to vaccination status. Vaccine effectiveness was defined as (1 - odds ratio) × 100%. RESULTS: A total of 3,908 positive and 16,090 negative results were included in the analyses. Receiving a bivalent dose in addition to ≥ 2 monovalent doses was 33.6% (95% confidence interval [CI]: 20.8, 44.3%) more effective than receiving no vaccination, and 18.2% (95% CI: 9.4, 26.0%) more effective than receiving ≥ 2 monovalent doses but not receiving a bivalent vaccination. In addition, the effectiveness peaked at 14-20 days after administration and then gradually declined over time. Furthermore, a bivalent booster dose provided 18.6% (95% CI: 9.9, 26.5%) additional protection among those vaccinated with ≥ 2 monovalent doses, in the absence of a previous infection history. However, we did not find sufficient evidence of effectiveness of bivalent vaccines among previously infected older adults. CONCLUSIONS: Bivalent vaccines are effective against COVID-19 infections among older adults without a history of infection.

Changes in the Utilization of Outpatient and Visiting Dental Care and Per-attendance Care Cost by Age Groups During COVID-19 Pandemic Waves in Japan: A Time-series Analysis From the LIFE Study.

BACKGROUND: The influence of the coronavirus disease 2019 (COVID-19) pandemic on dental care utilization may have differed according to individual characteristics or type of dental care provision. This study aimed to evaluate the changes in dental care utilization and per-attendance costs by age group and type of dental care during the COVID-19 pandemic in Japan. METHODS: This time-series study used healthcare insurance claims data from 01/07/2019 to 09/27/2021 (143 weeks) from nine municipalities in Japan. Dental care utilization rate per week and average dental care cost per attendance by age groups (0-19 years/20-64 years/65-74 years/≥75 years) and types of dental care (outpatient/visiting) were used as outcome variables. COVID-19 pandemic waves in Japan were used as predictors: 1st (03/23/2020-05/17/2020), 2nd (06/22/2020-09/27/2020), 3rd (10/26/2020-02/21/2021), 4th (02/22/2021-06/07/2021), and 5th (07/05/2021-09/13/2021) waves. Fixed-effects models were employed to estimate the proportional changes. RESULTS: In the fixed-effects model, we observed large declines in dental care utilization during the 1st (17.0-22.0%) and 2nd waves (3.0-13.0%) compared to the non-pandemic wave period in all age groups. In contrast, the average dental care cost per attendance increased in all age groups by 5.2-8.6% during the 1st wave. CONCLUSION: During the initial wave of the COVID-19 pandemic in Japan, dental care utilization decreased in all age groups, whereas the average dental care cost per attendance increased. The COVID-19 pandemic may have changed the dental care provision pattern towards less frequent and more concentrated dental care to avoid the risk of infection.

A principal component analysis of metabolome and cognitive decline among Japanese older adults: cross-sectional analysis using Tohoku Medical Megabank Cohort Study.

BackgroundDementia is the leading cause of disability and imposes a significant burden on society. Previous studies have suggested an association between metabolites and cognitive decline. Although the metabolite composition differs between Western and Asian populations, studies targeting Asian populations remain scarce.MethodsThis cross-sectional study used data from a cohort survey of community-dwelling older adults aged ≥ 60 years living in Miyagi, Japan, conducted by Tohoku Medical Megabank Organization between 2013 and 2016. Forty-three metabolite variables quantified using nuclear magnetic resonance spectroscopy were used as explanatory variables. Dependent variable was the presence of cognitive decline (≤ 23 points), assessed by the Mini-Mental State Examination. Principal component (PC) analysis was performed to reduce the dimensionality of metabolite variables, followed by logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for cognitive decline.ResultsA total of 2,940 participants were included (men: 49.0%, mean age: 67.6 years). Among them, 1.9% showed cognitive decline. The first 12 PC components (PC1-PC12) accounted for 71.7% of the total variance. Multivariate analysis showed that PC1, which mainly represented essential amino acids, was associated with lower odds of cognitive decline (OR = 0.89; 95% CI, 0.80-0.98). PC2, which mainly included ketone bodies, was associated with cognitive decline (OR = 1.29; 95% CI, 1.11-1.51). PC3, which included amino acids, was associated with lower odds of cognitive decline (OR = 0.81; 95% CI, 0.66-0.99).ConclusionAmino acids are protectively associated with cognitive decline, whereas ketone metabolites are associated with higher odds of cognitive decline.

Tooth loss mediates the association between smoking and an increased risk of dementia among older adults: The JAGES prospective cohort study.

AIM: Tooth loss has various causes; however, its cause-specific effects on health outcomes remain unclear. This study evaluated whether the association between past/current smoking and risk of dementia was mediated by tooth loss. MATERIALS AND METHODS: This 9-year-follow-up prospective cohort study targeted adults aged ≥65 years. Dementia incidence during 2013-2019, smoking status (never, past/current) in 2010 and the number of remaining teeth (≤19, ≥20) in 2013 were the outcome, exposure and mediator, respectively. We used causal mediation analysis to fit the Cox proportional hazards model and estimated the hazard ratio (HR) and 95% confidence interval (CI) of the natural indirect effect (NIE) of smoking on dementia incidence through tooth loss and their mediated proportions. RESULTS: Among 32,986 participants (mean age 72.6 years [1 SD = 5.4]; men 48.4%), the dementia incidence during follow-up was 2.11/100 person-years. Tooth loss significantly mediated the association between past/current smoking and dementia incidence; the NIE of fewer remaining teeth for past/current smokers compared to never smokers was HR = 1.03 (95% CI: 1.02-1.05), and the mediated proportion was 18.0%. CONCLUSIONS: Tooth loss significantly mediates the association between past/current smoking and an increased risk of dementia among older adults.

The association between objective and subjective oral health conditions and the presence of anorexia of aging among Japanese older Adults1.

Anorexia of aging is a risk factor for malnutrition among older adults. This study aimed to evaluate the association between objective and subjective oral health and anorexia among independent older adults. This cross-sectional study targeted independent older adults aged ≥65 years who participated in the Japan Gerontological Evaluation Study conducted in 2022. The outcome variable was the presence of anorexia, as assessed by the Simplified Nutritional Appetite Questionnaire. Exposure variables were dental status (≥20 teeth, 10-19 teeth with/without dentures, and 0-9 teeth with/without dentures) as objective oral health and oral health-related quality of life measured by five items of the short version of the Oral Impacts on Daily Performances (OIDP) (eating, speaking, smiling, emotional stability, and enjoying with others) as subjective oral health. We fitted the Poisson regression model, including possible confounders, and estimated prevalence ratios (PRs) and 95% confidence intervals. Among 19,787 participants (mean age: 74.6 years [1SD = 6.2], male: 48.5%), 9.0% were classified as having anorexia. After adjusting possible confounders, those with ≤19 teeth had a higher proportion of experiencing anorexia compared to those with ≥20 teeth; however, the association was less pronounced among those with dentures (0-9 teeth with dentures: PR = 1.48 [1.31-1.68], and 0-9 teeth without dentures: PR = 2.08 [1.65-2.63]). Even after adjusting for dental status, each item of OIDP was significantly associated with the presence of anorexia (all p < 0.05). The results showed that both objective and subjective poor oral health were significantly associated with a higher probability of developing anorexia of aging. Therefore, improving both objective and subjective oral health through appropriate dental care could contribute to maintaining appetite in later life.

Differences in prevalence of self-reported oral hypofunction between older adult patients with rheumatoid arthritis and the general older population: A cross-sectional study using propensity score matching.

OBJECTIVE: To examine the association between rheumatoid arthritis (RA) and oral hypofunction (OHF) using propensity score matching (PSM) to adjust for differences between older adults with RA and the general older adult population. METHODS: We conducted a cross-sectional survey among 189 older adults with RA in 2019 (mean age, 71.9 ± 3.6) and 47 178 independent older adult residents in 2016 (mean age, 71.6 ± 4.0), respectively. The questionnaire covered information on socio-demographic characteristics and OHF for both groups. Age, sex, educational level and smoking history were used to determine PSM. Prevalence ratios (PRs) and 95% confidence intervals (CIs) of self-reported OHF (fewer remaining teeth, decreased masticatory function, deterioration of swallowing function and oral dryness) were estimated using Poisson regressions. RESULT: OHF was observed in 44.4% of patients with RA and 27.5% of residents. Before PSM, the prevalence of OHF among patients with RA was higher than that of residents (PR, 1.75; 95% CI, 1.50-2.05). After PSM, there were 189 patients with RA and residents, and the prevalence of OHF among patients with RA was still higher (PR, 1.61; 95% CI, 1.22-2.13). Poisson regression showed that the prevalence of 19 or fewer teeth (PR, 1.06; 95% CI, 0.82-1.36), difficulties eating tough foods (PR, 1.18; 95% CI, 0.90-1.55), difficulties swallowing tea or soup (PR, 1.77; 95% CI, 1.19-2.63), and dry mouth (PR, 2.79; 95% CI, 1.90-4.07) was higher among patients with RA than residents. CONCLUSION: Compared with the general older adult population, patients with RA have a higher prevalence of self-reported OHF.

Compliance Trajectory and Patterns of COVID-19 Preventive Measures, Japan, 2020-2022.

COVID-19 remains a global health threat. Compliance with nonpharmaceutical interventions is essential because of limited effectiveness of COVID-19 vaccines, emergence of highly contagious variants, and declining COVID-19 antibody titers over time. We evaluated compliance with 14 nonpharmaceutical intervention-related COVID-19 preventive behaviors, including mask wearing, ventilation, and surface sanitation, in a longitudinal study in Japan using 4 waves of Internet survey data obtained during 2020-2022. Compliance with most preventive behaviors increased or remained stable during the 2-year period, except for surface sanitation and going out behaviors; compliance with ventilation behavior substantially decreased in winter. Compliance patterns identified from latent class analysis showed that the number of persons in the low compliance class decreased, whereas those in the personal hygiene class increased. Our findings reflect the relaxation of mobility restriction policy in Japan, where the COVID-19 pandemic continues. Policymakers should consider behavioral changes caused by new policies to improve COVID-19 prevention strategies.

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.

Health-related quality of life in various health conditions: two consecutive surveys of older Japanese adults.

PURPOSE: Measuring health-related quality of life (HRQOL) in various health conditions in different countries is important given the regional differences. This study employed large-scale nationwide data targeting older adults in Japan to estimate the HRQOL in the key health conditions that are the major causes of disability. METHODS: Our data were derived from two survey waves (2016 and 2019 surveys) of cross-sectional data from the Japan Gerontological Evaluation Study, an ongoing nationwide study targeting functionally independent older adults in Japan. A total of 28,345 individuals from 27 of the 47 Japanese provinces were analyzed. The EuroQoL 5-dimension 5-level instrument (EQ-5D-5L) was employed to assess the HRQOL utility scores. The targeted minimum loss-based estimator with sampling weighting methods was applied to estimate the utility score in eight major health conditions, including sensory organ disease, musculoskeletal disease, oral disorders, and depressive disorders. RESULTS: The estimated HRQOL utility score for those with the poorest health conditions in self-rated health, hearing loss, vision loss, number of remaining teeth (e.g., no teeth with no denture use), oral dysfunction, depressive symptoms, chronic low back pain, and chronic knee pain was 0.576 (95% confidence interval (CI) 0.555-0.598), 0.768 (95% CI 0.737-0.800), 0.680 (95% CI 0.662-0.699), 0.809 (95% CI 0.796-0.821), 0.776 (95% CI 0.764-0.788), 0.723 (95% CI 0.710-0.737), 0.715 (95% CI 0.690-0.739), and 0.742 (95% CI 0.722-0.763), respectively. CONCLUSION: We successfully provided a catalog for the HRQOL utility score in key health conditions that are the leading causes of disability among older adults.

Oral status and homebound status: A 6-year bidirectional exploratory prospective cohort study.

OBJECTIVES: Little is known about the association between oral status and homebound status, and there is a possibility of a bidirectional relationship between them. In this exploratory prospective cohort study, we examined the association between four oral status measurements and being homebound bidirectionally. METHODS: We used 2010-2016 panel data gathered from the Japan Gerontological Evaluation Study. All functionally independent participants aged 65 years or older (n = 26,579) were included in this study. Multiple imputation and Poisson regression were used for analyses. We adjusted for age, sex, education, comorbidity, and depressive symptoms. RESULTS: In the fully adjusted model, the prevalence ratio (PR) of being homebound at follow-up was 1.42 for having <20 remaining teeth, 1.28 for having chewing difficulty, 0.99 for having choking experience, and 0.94 for having dry mouth at baseline. Reversely, being homebound at baseline predicted having chewing difficulty at follow-up (PR = 1.17), while no significant association was demonstrated with having <20 teeth (PR = 1.00), choking experience (PR = 1.06), and dry mouth (PR = 1.02). CONCLUSION: Chewing difficulty and having <20 remaining teeth predicted homebound status after 6 years. Reversely, homebound status at baseline only predicted having chewing difficulty at follow-up. These findings may help to determine the oral frailty assessment measures for older people.

Dental prosthesis use is associated with higher protein intake among older adults with tooth loss.

BACKGROUND: Tooth loss is associated with reduced protein intake, which leads to sarcopenia and frailty in older adults. OBJECTIVE: To evaluate the protective effect of dental prostheses on decreased protein intake in older adults with tooth loss. METHODS: This cross-sectional study was based on a self-reported questionnaire targeting older adults. Data were obtained from the Iwanuma Survey of the Japan Gerontological Evaluation Study. We used % energy intake (%E) of total protein as the outcome and the use of dental prostheses and number of remaining teeth as explanatory variables. We estimated the controlled direct effects of tooth loss by fixing the use/non-use of dental prostheses based on a causal mediation analysis, including possible confounders. RESULTS: Among 2095 participants, the mean age was 81.1 years (1SD = 5.1), and 43.9% were men. The average protein intake was 17.4%E (1SD = 3.4) of the total energy intake. Among participants with ≥20, 10-19 and 0-9 remaining teeth, the average protein intake was 17.7%E, 17.2%E/17.4%E and 17.0%E/15.4%E (with/without a dental prosthesis), respectively. Compared to participants with ≥20 remaining teeth, those with 10-19 remaining teeth without a dental prosthesis did not have a significantly different total protein intake (p > .05). Among those with 0-9 remaining teeth without a dental prosthesis, total protein intake was significantly low (-2.31%, p < .001); however, the use of dental prostheses mitigated the association by 79.4% (p < .001). CONCLUSION: Our results suggest that prosthodontic treatment could contribute to maintaining protein intake in older adults with severe tooth loss.

Lower socio-economic status in adolescence is associated with poor oral health at an older age: Mediation by social and behavioural factors.

AIM: To examine the mediators between lower socio-economic status (SES) in adolescence and oral health at an older age to uncover the underlying mechanisms of the association. METHODS: Participants (n = 21 536) aged ≥65 years from the Japan Gerontological Evaluation Study were evaluated. The dependent variables were self-rated chewing difficulty and having ≤19 remaining teeth. The main independent variable was self-perceived SES in adolescence. The Karlson-Holm-Breen method was used for mediation analysis. RESULTS: Mean age of the participants was 74.8 years (standard deviation = 6.4), and 51.5% were female. Overall, 5598 (26.0%) participants reported chewing difficulty and 9404 (43.7%) had ≤19 remaining teeth. Lower SES in adolescence was associated with a higher prevalence of chewing difficulty (odds ratio [OR] = 1.38, 95%confidence interval [CI] = 1.29-1.48; total effect). After controlling for mediators, OR for lower SES in adolescence was 1.22 (95%CI = 1.13-1.30; direct effect) and 1.13 (95%CI = 1.11-1.16; indirect effect). Mediators, prominently the number of teeth and income, explained 39.3% of the associations. Lower SES in adolescence increased the odds of ≤19 remaining teeth by OR = 1.23 (95% CI = 1.16-1.31; total effect). After controlling for mediators, the OR for lower SES in adolescence was 1.03 (95%CI = 0.97-1.10; direct effect) and 1.19 (95%CI = 1.16-1.23; indirect effect). Mediators, prominently educational attainment, explained 85.0% of the associations. CONCLUSIONS: Lower SES in adolescence was associated with poor oral health at an older age through mediators. Approaches that consider social determinants from the beginning of the life course are required.

An Interpretable Machine Learning Approach to Predict Fall Risk Among Community-Dwelling Older Adults: a Three-Year Longitudinal Study.

BACKGROUND: Adverse health effects resulting from falls are a major public health concern. Although studies have identified risk factors for falls, none have examined long-term prediction of fall risk. Furthermore, recent evidence suggests that there are additional risk factors, such as psychosocial factors. OBJECTIVE: In this 3-year longitudinal study, we evaluated a predictive model for risk of fall among community-dwelling older adults using machine learning methods. DESIGN: A 3-year follow-up prospective longitudinal study (from 2010 to 2013). SETTING: Twenty-four municipalities in nine of the 47 prefectures (provinces) of Japan. PARTICIPANTS: Community-dwelling individuals aged ≥65 years who were functionally independent at baseline (n = 61,883). METHODS: The baseline survey was conducted from August 2010 to January 2012, and the follow-up survey was conducted from October to December 2013. Both surveys were conducted involving self-reported questionnaires. The measured outcome at the follow-up survey was self-reported multiple falls during the previous year. The 142 variables included in the baseline survey were regarded as candidate predictors. The random-forest-based Boruta algorithm was used to select predictors, and the eXtreme Gradient Boosting algorithm with 10 repetitions of nested k-fold cross-validation was used for modeling and model evaluation. Furthermore, we used shapley additive explanations to gain insight into the behavior of the prediction model. KEY RESULTS: Fourteen out of 142 candidate features were selected as predictors. Among these predictors, experience of falling as of the baseline survey was the most important feature, followed by self-rated health and age. Moreover, sense of coherence was newly identified as a risk factor for falls. CONCLUSIONS: This study suggests that machine learning tools can be adapted to explore new associative factors, make accurate predictions, and provide actionable insights for fall prevention strategies.

Longitudinal Association Between Oral Status and Cognitive Decline Using Fixed-effects Analysis.

BACKGROUND: Although the feasibility of randomized trials for investigating the long-term association between oral health and cognitive decline is low, deriving causal inferences from observational data is challenging. We aimed to investigate the association between poor oral status and subjective cognitive complaints (SCC) using fixed-effects model to eliminate the confounding effect of unobserved time-invariant factors. METHODS: We used data from Japan Gerontological Evaluation Study (JAGES) which was conducted in 2010, 2013, and 2016. ß regression coefficients and 95% confidence intervals [CIs] were calculated using fixed-effects models to determine the effect of deteriorating oral status on developing SCC. Onset of SCC was evaluated using the Kihon Checklist-Cognitive function score. Four oral status variables were used: awareness of swallowing difficulty, decline in masticatory function, dry mouth, and number of teeth. RESULTS: We included 13,594 participants (55.8% women) without SCC at baseline. The mean age was 72.4 (standard deviation [SD], 5.1) years for men and 72.4 (SD, 4.9) years for women. Within the 6-year follow-up, 26.6% of men and 24.9% of women developed SCC. The probability of developing SCC was significantly higher when participants acquired swallowing difficulty (ß = 0.088; 95% CI, 0.065-0.111 for men and ß = 0.077; 95% CI, 0.057-0.097 for women), decline in masticatory function (ß = 0.039; 95% CI, 0.021-0.057 for men and ß = 0.030; 95% CI, 0.013-0.046 for women), dry mouth (ß = 0.026; 95% CI, 0.005-0.048 for men and ß = 0.064; 95% CI, 0.045-0.083 for women), and tooth loss (ß = 0.043; 95% CI, 0.001-0.085 for men and ß = 0.058; 95% CI, 0.015-0.102 for women). CONCLUSION: The findings suggest that good oral health needs to be maintained to prevent the development of SCC, which increases the risk for future dementia.

The lack of opportunity to eat together is associated with an increased risk of weight loss among independent older adults: a prospective cohort study based on the JAGES.

OBJECTIVE: the present study aimed to investigate the relationship between the frequency of eating together and the risk of weight loss in older adults. METHODS: this was a three-year follow-up prospective cohort study based on a self-reported questionnaire. We used data from the Japan Gerontological Evaluation Study (JAGES) conducted in 2016 and 2019. The participants were independent older adults aged ≥65 years in Japan. We used >5% weight loss during follow-up as the outcome variable and frequency of eating together as the explanatory variable. The relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated based on the Poisson regression model with a Huber-White sandwich estimator for standard errors, including possible confounders. RESULTS: among 56,919 participants, the mean age was 73.0 years (1SD = 5.5) at baseline, and 47.9% were male. About 15.1% (n = 8,596) of the participants experienced >5% weight loss during follow-up. The proportion of each category of the eating together frequency was 36.6% for 'every day', 10.3% for 'several times a week', 26.8% for 'several times a month', 20.5% for 'several times a year' and 5.8% for 'seldom'. Compared to 'every day', only 'several times a year (RR = 1.07, 95% CI = 1.01-1.13)' and 'seldom (RR = 1.17, 95% CI = 1.08-1.27)' were significantly associated with the increased risk of >5% weight loss. CONCLUSION: there is a temporal association between less frequent opportunities to eat together and the increased risk of weight loss among independent older adults.

Association of poor dental status with eating alone: A cross-sectional Japan gerontological evaluation study among independent older adults.

Eating alone is reported to deteriorate health; however, the relationship between eating alone and poor dental health remains unclear. This cross-sectional study aimed to investigate the association between poor dental health and eating alone. Data of participants (n = 156,287) aged ≥65 years from the Japan Gerontological Evaluation Study were evaluated using logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association between dental status, including prosthesis use, and eating status. Differences in these associations according to living status were also examined. The mean age of participants was 73.7 (SD = 6.0) years. The percentages of participants eating alone with 20 or more teeth, 10-19 teeth with dental prostheses, 0-9 teeth with dental prostheses, 10-19 teeth without dental prostheses, and 0-9 teeth without dental prostheses were 13.8%, 16.0%, 18.6%, 18.9%, and 27.0%, respectively. After adjusting for covariates, participants with 0-9 teeth without any dental prosthesis showed a significantly higher odds ratio for eating alone (OR = 1.81, 95% CI = 1.58-2.07) than those with 20 or more teeth. Among participants with poorer dental status, the probability of eating alone was higher in those living alone than in those living with others. Among older adults, poor dental status was significantly associated with eating alone, and this association was stronger among those living alone. Maintaining better dental status by using a dental prosthesis might reduce the risk of eating alone, especially for those living alone.

Association among the number of teeth, dental prosthesis use, and subjective happiness: A cross-sectional study from the Japan Gerontological Evaluation study (JAGES).

STATEMENT OF PROBLEM: Little is known about the association between the number of teeth and self-rated happiness or the association between dental prosthesis use and self-rated happiness in an older population. PURPOSE: The purpose of this cross-sectional study was to examine the association between the number remaining of teeth with and without dental prosthesis use and self-rated happiness in an older population. MATERIAL AND METHODS: The survey data from the 2016 Japan Gerontological Evaluation Study (JAGES) on independent participants aged 65 years or older were assessed. The Poisson regression and multiple imputation methods were used for analyses. Covariates were age, sex, marital status, educational attainment, self-rated health, self-rated economic situation, and symptoms of depression. RESULTS: The data from 178 090 participants, 81 489 men (45.8%) and 96 601 women (54.2%), were analyzed, with a mean ±standard deviation age of 73.6 ±6.1 years. Overall, 66.4% of the participants were happy, declining to 45.7% in those who had 0 to 9 teeth and no dental prosthesis (n=3102). It was 61.5% in those who had 0 to 9 teeth and used a dental prosthesis (n=41 424), 56.8% in those who had 10 to 19 teeth and no dental prosthesis (n=6719), 65% in those who had 10 to 19 teeth and used a dental prosthesis (n=31 592), 70.5% in those who had ≥20 teeth and no dental prosthesis (n=52 525), and 70.1% in those who had ≥20 teeth and used a dental prosthesis (n=42 728). The interaction analysis showed that the reduction in the probability of being happy among those with fewer teeth was smaller among those who used a dental prosthesis. CONCLUSIONS: Having a higher number of teeth and using a dental prosthesis were independently associated with being happy. A significant interaction suggested that dental prosthesis use improves happiness among those with moderate to severe tooth loss (<20 remaining teeth).

Proactive Engagement of the Expert Meeting in Managing the Early Phase of the COVID-19 Epidemic, Japan, February-June 2020.

To deal with the risk of emerging diseases with many unknowns, close and timely collaboration and communication between science experts and policymakers are crucial to developing and implementing an effective science-based intervention strategy. The Expert Meeting, an ad hoc medical advisory body, was established in February 2020 to advise Japan's COVID-19 Response Headquarters. The group played an important role in the policymaking process, promoting timely situation awareness and developing science-based proposals on interventions that were promptly reflected in government actions. However, this expert group may have been overly proactive in taking on the government's role in crisis management. For the next stage of managing the coronavirus disease pandemic and future pandemics, the respective roles of the government and its advisory bodies need to be clearly defined. Leadership and strategic risk communication by the government are key.

Heated Tobacco Products Have Reached Younger or More Affluent People in Japan.

BACKGROUND: The trend of the diffusion of heated tobacco products (HTPs) is a great concern because HTPs have become available worldwide. This study examined the sociodemographic characteristics of HTPs users in Japan, where HTPs were first launched. METHODS: This cross-sectional study used data from an online survey conducted in 2017. A total of 4,926 participants, aged 20-69 years, were included. The dependent variable was the type of tobacco products used. The independent variables were age and equivalent income. Two analyses estimated the odds ratios (ORs) for 1) being smokers compared to "non-smokers," and 2) being "HTP smokers" compared to "only combustible cigarette smokers." Analyses were stratified by sex. Educational attainment and occupation were also used in the sensitivity analyses. RESULTS: The percentages of "non-smokers," "only combustible cigarette smokers," and "HTP smokers" were 82.8%, 14.2%, and 3.0%, respectively. When compared to the oldest participants (aged 60-69), the youngest participants (aged 20-29) tended to be "HTP smokers" (OR 7.90; 95% confidence interval [CI], 3.09-20.22 for men and OR 9.28; 95% CI, 2.14-40.28 for women). Compared to participants with the lowest incomes (<2 million), those with the highest incomes (≥4 million) tended to use HTPs (OR 2.93; 95% CI, 1.56-5.49 in men and OR 1.82; 95% CI, 0.73-4.54 in women). These trends were consistent when analyses included only smokers. There were consistent results in other SES measurements, including educational attainment and occupation. CONCLUSIONS: Younger or more affluent people tended to use HTPs, although smoking rates among these populations were generally lower. New tobacco control efforts are required.

Association Between Social Isolation and Smoking in Japan and England.

BACKGROUND: Existing evidence suggest that those who are socially isolated are at risk for taking up or continuing smoking. This study investigated country-based differences in social isolation and smoking status. METHODS: We performed a repeated cross-sectional study using two waves of data from two ongoing aging studies: the English Longitudinal Study of Ageing and the Japan Gerontological Evaluation Study. Participants from both studies aged ≥65 years were included. We applied a multilevel Poisson regression model to examine the association between social isolation and smoking status and adjusted for individual sociodemographic characteristics. We used the social isolation index which comprises the following domains: marital status; frequency of contact with friends, family, and children; and participation in social activities. Interaction terms between each country and social isolation were also entered into the mode. RESULTS: After exclusion of never smokers, we analyzed 75,905 participants (7,092 for ELSA and 68,813 for JAGES, respectively). Taking ex-smokers as the reference, social isolation was significantly associated with current smoking; the prevalence ratios (PRs) were 1.06 (95% credible interval [CrI], 1.05-1.08) for men and 1.08 (95% CrI, 1.04-1.11) for women. Taking Japan as a reference, the interaction term between country and social isolation was significant for both sexes, with increased PRs of 1.32 (95% CrI, 1.14-1.50) for men and 1.30 (95% CrI, 1.11-1.49) for women in England. CONCLUSIONS: Older people who were less socially isolated were more likely to quit smoking in England than in Japan, possibly explained by the strict tobacco control policies in England.