Associations between COVID-19 vaccination and incident psychiatric disorders after breakthrough SARS-CoV-2 infection: The VENUS Study.

BACKGROUND: The associations between COVID-19 vaccination and post-COVID psychiatric disorders are unclear. Furthermore, it is uncertain if these associations differ depending on the dominant SARS-CoV-2 variant at the time of infection. This retrospective cohort study aimed to clarify the associations between COVID-19 vaccination and incident psychiatric disorders after breakthrough infection according to the different variant periods in Japan. METHODS: Medical claims data, COVID-19 case-related information, and vaccination records were collected from three Japanese municipalities. The study population comprised public insurance enrollees aged ≥65 years who developed COVID-19 between June 2021 and December 2022. The study exposure was each participant's vaccination status 14 days before infection, and the outcomes were the occurrence of psychiatric disorders within three months of infection. Multivariable logistic regression analyses were performed to calculate the odds ratios (ORs) and 95 % confidence intervals (CIs) of vaccination for the occurrence of psychiatric disorders. Analyses were conducted for the Delta period (June to December 2021), Omicron BA.1/BA.2 period (January to June 2022), and Omicron BA.5 period (July to December 2022). RESULTS: We analyzed 270 participants (vaccinated: 149) in the Delta period, 2,963 participants (vaccinated: 2,699) in the Omicron BA.1/BA.2 period, and 7,723 participants (vaccinated: 7,159) in the Omicron BA.5 period. During the Delta period, vaccinated participants had significantly lower odds for psychotic disorders (OR: 0.23, 95 % CI: 0.06-0.88, P = 0.032) than unvaccinated participants. During the Omicron BA.5 period, vaccinated participants had significantly lower odds for organic mental disorders (OR: 0.54, 95 % CI: 0.30-0.95, P = 0.033), psychotic disorders (OR: 0.31, 95 % CI: 0.19-0.53, P < 0.001), mood disorders (OR: 0.53, 95 % CI: 0.29-0.99, P = 0.046), and insomnia (OR: 0.48, 95 % CI: 0.32-0.72, P < 0.001) than unvaccinated participants. There were no significant differences in psychiatric disorders between the vaccinated and unvaccinated groups during the Omicron BA.1/BA.2 period. CONCLUSIONS: This is the first study to demonstrate that the associations between COVID-19 vaccination and post-COVID psychiatric disorders vary among the different variant periods. Future studies on these associations should be conducted with consideration to the prevalent circulating variants.

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.

Post-discharge functional outcomes in older patients with sepsis.

BACKGROUND: The post-discharge prognosis of patients with sepsis remains a crucial issue; however, few studies have investigated the relationship between pre-sepsis health status and subsequent prognosis in a large population. This study aimed to examine the effect of the pre-sepsis care needs level on changes in care needs and mortality in patients with sepsis 1 year post-discharge. METHODS: This was a population-based retrospective cohort study including twelve municipalities in Japan that participated in the Longevity Improvement & Fair Evidence study between April 2014 and March 2022, with a total of 1,491,608 persons. The pre-hospitalization levels of care needs (baseline) were classified from low to high, as no care needs, support level and care needs level 1, care needs levels 2-3, and care needs levels 4-5 (fully dependent). The outcomes were changes in care needs level and mortality 1 year post-discharge, assessed by baseline care needs level using Cox proportional hazard models. RESULTS: The care needs levels of 17,648 patients analyzed at baseline were as follows: no care needs, 7982 (45.2%); support level and care needs level 1, 3736 (21.2%); care needs levels 2-3, 3089 (17.5%); and care needs levels 4-5, 2841 (16.1%). At 1 year post-discharge, the distribution of care needs were as follows: no care needs, 4791 (27.1%); support level and care needs level 1, 2390 (13.5%); care needs levels 2-3, 2629 (14.9%); care needs levels 4-5, 3373 (19.1%); and death, 4465 (25.3%). Patients with higher levels of care needs exhibited an increased association of all-cause mortality 1 year post-discharge after adjusting for confounders [hazard ratios and 95% confidence intervals: support level and care needs level 1, 1.05 (0.96, 1.15); care needs levels 2-3, 1.46 (1.33, 1.60); and care needs levels 4-5, 1.92 (1.75, 2.10); P for trend < 0.001]. CONCLUSIONS: Elevated care needs and mortality were observed in patients with sepsis within 1 year post-discharge. Older patients with sepsis and higher baseline levels of care needs had a high association of all-cause mortality 1 year post-discharge.

Validation Study of the Claims-Based Algorithm Using the International Classification of Diseases Codes to Identify Patients With Coronavirus Disease in Japan From 2020 to 2022: The VENUS Study.

PURPOSE: We validated claims-based algorithms using the International Classification of Diseases, Tenth Revision (ICD-10) to identify patients with the first-ever coronavirus disease (COVID-19) onset between May 2020 and August 2022. METHODS: The study cohort was comprised of residents of one municipality enrolled in a public insurance program. This study used data provided by the municipality, including residents' insurer-based medical claims data linked to the Health Center Real-time Information-Sharing System (HER-SYS). The HER-SYS data included positive results from COVID-19 tests and were used as reference standards. Claims-based algorithms #1 and #2 were U07.1, B34.2, with and without suspicious diagnoses, respectively. Claims-based algorithms #3 and #4 were U07.1 with and without suspicious diagnoses, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each algorithm. RESULTS: The study cohort included 165 038 residents, including 13 402 residents were the reference standard. For the entire period, the sensitivity, specificity, PPV, and NPV were 55.7% (95% confidence interval: 54.8%-56.5%), 65.4% (65.2%-65.6%), 11.5% (11.3%-11.8%), and 98.9% (98.8%-99.0%) for Algorithm #1, and 67.0% (66.2%-67.8%), 88.1% (87.9%-88.3%), 31.6% (31.1%-32.2%), and 97.8% (97.7%-97.8%) for Algorithm #2, and 52.9% (52.0%-53.7%), 67.1% (66.9%-67.3%), 11.5% (11.2%-11.8%), and 98.3% (98.3%-98.4%) for Algorithm #3, 62.6% (61.8%-63.4%), 88.5% (88.3%-88.7%), 30.9% (30.3%-31.4%), and 97.3% (97.2%-97.4%) for Algorithm #4, respectively. CONCLUSIONS: Our study showed that the validity of claims-based algorithms consisting of COVID-19-related ICD-10 codes to identify patients with first-onset COVID-19 is limited.

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 LIFE study.

BACKGROUND: The influence of the coronavirus disease (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 (0-19y/20-64y/65-74y/≥ 75y) 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 effect models were employed to estimate the proportional changes. RESULTS: In the fixed effect 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. CONCLUSIONS: 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.

Postdischarge functional outcomes in older patients with acute heart failure in Japan: the Longevity Improvement & Fair Evidence study.

BACKGROUND: The association between care needs level (CNL) at hospitalisation and postdischarge outcomes in older patients with acute heart failure (aHF) has been insufficiently investigated. METHODS: This population-based cohort study was conducted using health insurance claims and CNL data of the Longevity Improvement & Fair Evidence study. Patients aged ≥65 years, discharged after hospitalisation for aHF between April 2014 and March 2022, were identified. CNLs at hospitalisation were classified as no care needs (NCN), support level (SL) and CNL1, CNL2-3 and CNL4-5 based on total estimated daily care time as defined by national standard criteria, and varied on an ordinal scale between SL&CNL1 (low level) to CNL4-5 (fully dependent). The primary outcomes were changes in CNL and death 1 year after discharge, assessed by CNL at hospitalisation using Cox proportional hazard models. RESULTS: Of the 17 724 patients included, 7540 (42.5%), 4818 (27.2%), 3267 (18.4%) and 2099 (11.8%) had NCN, SL&CNL1, CNL2-3 and CNL4-5, respectively, at hospitalisation. One year after discharge, 4808 (27.1%), 3243 (18.3%), 2968 (16.7%), 2505 (14.1%) and 4200 (23.7%) patients had NCN, SL&CNL1, CNL2-3, CNL4-5 and death, respectively. Almost all patients' CNLs worsened after discharge. Compared to patients with NCN at hospitalisation, patients with SL&CNL1, CNL2-3 and CNL4-5 had an increased risk of all-cause death 1 year after discharge (hazard ratio [95% confidence interval]: 1.19 [1.09-1.31], 1.88 [1.71-2.06] and 2.56 [2.31-2.84], respectively). CONCLUSIONS: Older patients with aHF and high CNL at hospitalisation had a high risk of all-cause mortality in the year following discharge.

Association between seasonal influenza vaccination and antimicrobial use in Japan from the 2015-16 to 2020-21 seasons: from the VENUS study.

BACKGROUND: Seasonal influenza vaccination might be considered an antimicrobial resistance (AMR) countermeasure because it can reduce unnecessary antimicrobial use for acute respiratory infection by mitigating the burden of such diseases. OBJECTIVES: To examine the association between seasonal influenza vaccination and antimicrobial use (AMU) in Japan at the community level and to examine the impact of influenza vaccination on the frequency of unnecessary antimicrobial prescription for upper respiratory infection. METHODS: For patients who visited any healthcare facility in one of the 23 wards of Tokyo, Japan, due to upper respiratory infection and who were aged 65 years or older, we extracted data from the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study database, which includes all claims data and vaccination records from the 2015-16 to 2020-21 seasons. We used the average treatment effect (ATE) with 1:1 propensity score matching to examine the association of vaccination status with frequency of antibiotic prescription, frequency of healthcare facility consultation, risk of admission and risk of death in the follow-up period of the same season (from 1 January to 31 March). RESULTS: In total, 244 642 people were enrolled. Matched data included 101 734 people in each of the unvaccinated and vaccinated groups. The ATE of vaccination was -0.004 (95% CI -0.006 to -0.002) for the frequency of antibiotic prescription, -0.005 (-0.007 to -0.004) for the frequency of healthcare facility consultation, -0.001 (-0.002 to -0.001) for the risk of admission and 0.00 (0.00 to 0.00) for the risk of death. CONCLUSIONS: Our results suggest that seasonal influenza vaccination is associated with lower frequencies of unnecessary antibiotic prescription and of healthcare facility consultation.

Association of anticholinergic drug exposure with the risk of dementia among older adults in Japan: The LIFE Study.

OBJECTIVES: Several studies have investigated that anticholinergic drugs cause cognitive impairment. However, the risk of dementia associated with anticholinergics has not been extensively investigated in the super-aging society of Japan. We conducted this study to assess the association between anticholinergic drugs and the risk of dementia in older adults in Japan. METHODS: This nested case-control study used data from the Longevity Improvement & Fair Evidence Study, which includes claim data in Japan from 2014 to 2020. We included 66,478 cases of diagnosed dementia and 328,919 matched controls aged ≥65 years, matched by age, sex, municipality, and cohort entry year. Primary exposure was the total cumulative anticholinergic drugs prescribed from cohort entry date to event date or matched index date, which was the total standardized daily doses for each patient, calculated by adding the total dose of different types of anticholinergic drugs in each prescription, divided by the World Health Organization-defined daily dose values. Odds ratios for dementia associated with cumulative exposure to anticholinergic drugs were calculated using conditional logistic regression adjusted for confounding variables. RESULTS: The mean (standard deviation) age at index date was 84.3 (6.9), and the percentage of women was 62.1%. From cohort entry date to event date or matched index date, 18.8% of the case patients and 13.7% of the controls were prescribed at least one anticholinergic drug. In the multivariable-adjusted model, individuals with anticholinergic drugs prescribed had significantly higher odds of being diagnosed with dementia (adjusted odds ratio, 1.50 [95% confidence interval, 1.47-1.54]). Among specific types of anticholinergic drugs, a significant increase in risk was observed with the use of antidepressants, antiparkinsonian drugs, antipsychotics, and bladder antimuscarinics in a fully multivariable-adjusted model. CONCLUSIONS: Several types of anticholinergic drugs used by older adults in Japan are associated with an increased risk of dementia. These findings suggest that the underlying risks should be considered alongside the benefits of prescribing anticholinergic drugs to this population.

Effectiveness of BNT162b2 against infection, symptomatic infection, and hospitalization among older adults aged ≥65 years during the Delta variant predominance in Japan: The VENUS Study.

BACKGROUND: We evaluated the effectiveness of the BNT162b2 vaccine against infection, symptomatic infection, and hospitalization in older people during the Delta-predominant period (July 1 to September 30, 2021). METHODS: We performed a population-based cohort study in an older adult population aged ≥65 years using data from the Vaccine Effectiveness, Networking, and Universal Safety Study conducted from January 1, 2019, to September 30, 2021, in Japan. We matched BNT162b2 vaccinated and unvaccinated individuals in a 1:1 ratio on the date of vaccination of the vaccinated individual. We evaluated the effectiveness of the vaccine against infection, symptomatic infection, and COVID-19-related hospitalization by comparing the vaccinated and unvaccinated groups. We estimated the risk ratio and risk difference using the Kaplan-Meier method with inverse probability weighting. The vaccine effectiveness was calculated as (1 - risk ratio) × 100%. RESULTS: The study included 203,574 matched pairs aged ≥65 years. At 7 days after the second dose, the vaccine effectiveness (95% confidence interval) of BNT162b2 against infection, symptomatic infection, and hospitalization was 78.1% (65.2 to 87.8%), 79.1% (64.6 to 88.9%), and 93.5% (83.7 to 100%), respectively. CONCLUSIONS: BNT162b2 was highly effective against infection, symptomatic infection, and hospitalization in Japan's older adult population aged ≥65 years during the Delta-predominant period.

Analysis of post-extraction bleeding in patients taking antithrombotic therapy using data from the longevity improvement and fair evidence study.

BACKGROUND: Several studies have investigated post-extraction bleeding in patients on antithrombotic therapy, but most included a small sample size. OBJECTIVE: This study aimed to analyse post-extraction bleeding in patients on antithrombotic therapy using data from a large database. MATERIALS AND METHODS: Claims data of National Health Insurance and Late-Stage Elderly Healthcare System enrollees who underwent tooth extraction between October 2014 and March 2019 (n = 107 767) in a large multiregional cohort study (Longevity Improvement and Fair Evidence study) were included. Antithrombotic therapy was determined based on the drug codes used at the time of tooth extraction (classified into six groups: no antithrombotic, single antiplatelet, dual antiplatelet, Direct Oral Anticoagulant, warfarin and combined antiplatelet and anticoagulant therapies). The outcome was defined as the presence of "post-extraction bleeding" as a receipt disease name in the same month as tooth extraction. To examine the association between antithrombotic therapy and post-extraction bleeding in detail, multiple logistic regression analysis was performed with post-extraction bleeding as the objective variable; each antithrombotic therapy as the explanatory variable; and age, sex and comorbidities as adjustment variables. RESULTS: Antithrombotic therapy was administered in 14 343 patients (13.3%), and post-extraction bleeding was observed in 419 patients (0.4%). The rate of post-extraction bleeding was significantly lower in the no antithrombotic therapy and single antiplatelet groups than that in the other groups (odds ratio: 2.00-9.02). CONCLUSION: The frequency of post-extraction bleeding is high in patients on anticoagulation or dual antithrombotic therapy. Therefore, careful preparation before extraction is necessary in these patients.

Effect of income on length of stay in a hospital or long-term care facility among older adults with dementia in Japan.

OBJECTIVE: We aimed to ascertain the degree of influence of income disparity among older people with newly developed dementia on the probability and duration of stay in a hospital or long-term care facility and the degree of influence on medical expenses for hospitalization and care costs. METHODS: This was a retrospective cohort study. Study participants included 12 829 individuals aged 75 years or older not diagnosed with dementia between April 2012 and March 2013 but newly diagnosed with dementia between April 2013 and March 2014. Participants were categorized according to income. We evaluated the associations of income with the probability and duration of stay in a hospital or long-term care facility and the costs for hospitalization and care. RESULTS: In the adjusted analyses, high-income individuals had a lower probability of admission to a hospital or long-term care facility than middle- and high-income individuals. In all hospitals, low-income individuals had the longest duration of stay, but in long-term care facilities, income categories varied by facility type. Medical expenses for hospitalization and care costs were highest in the low-income group. CONCLUSION: Income category affects the probability and duration of stay in the hospital or a long-term care facility, as well as expenses for hospitalization and care. It is necessary to consider a policy to enable low-income older patients with dementia to continue living at home.

Protective Effects of 23-Valent Pneumococcal Polysaccharide Vaccination Against Mortality: The VENUS Study.

This retrospective matched cohort study investigated the protective effects of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) against pneumonia mortality and all-cause mortality in Japanese adults aged ≥65 years. We analyzed claims data, vaccination records, and death certificate records between October 2016 and December 2019 from 55 509 PPSV23-vaccinated individuals and 55 509 unvaccinated individuals. Cox proportional hazards analyses were performed to calculate the adjusted hazard ratios (HRs) of PPSV23 vaccination for mortality. The results showed that PPSV23 vaccination was significantly associated with a reduction in all-cause mortality (adjusted HR, 0.52; P < .001) but not pneumonia mortality (adjusted HR, 0.70; P = .374).

The age-specific impact of COVID-19 vaccination on medical expenditures and hospitalization duration after breakthrough infection: The Vaccine Effectiveness, Networking, and Universal Safety (VENUS) Study.

OBJECTIVES: Although COVID-19 no longer constitutes a Public Health Emergency of International Concern, vaccination remains an important tool for reducing disease burden and mitigating future outbreaks. However, little is known about the impact of vaccination on medical expenditures and hospitalization duration after breakthrough infection. This study aimed to examine this impact during the Delta wave in Japan. METHODS: This retrospective study was conducted using medical care claims data, vaccination records, and COVID-19-related information. COVID-19 cases in three municipalities were categorized into two age groups: 20-64 years and ≥65 years. For each group, we constructed linear regression models with a generalized estimating equation. We calculated the risk ratios (RRs) and 95% confidence intervals (CIs) of COVID-19 vaccination for total medical expenditures and hospitalization duration after adjusting for sex, comorbidities, and municipality. RESULTS: We analyzed 618 cases aged 20-64 years (mean age: 38.4 years, women: 45.1%) and 208 cases aged ≥65 years (76.4 years, 53.8%). The RRs (95% CIs) of vaccination for total medical expenditures were 0.53 (0.44-0.64) in the 20-64 years age group and 0.51 (0.39-0.66) in the ≥65 years age group. Next, the RRs (95% CIs) of vaccination for hospitalization duration were 0.59 (0.42-0.83) in the 20-64 years age group and 0.69 (0.49-0.98) in the ≥65 years age group. CONCLUSIONS: COVID-19 vaccination was associated with lower total medical expenditures and hospitalization duration after breakthrough infection, with a more pronounced effect in older persons.

Factors Associated With Hospitalization, Length of Stay, and Hospital Expenditures for Respiratory Syncytial Virus Infection in Japanese Infants and Children According to Palivizumab-indicated Underlying Conditions: The LIFE Study.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of pediatric respiratory tract infections. In Japan, children with specific underlying conditions are eligible to receive palivizumab to prevent severe RSV disease. However, the association between palivizumab eligibility and RSV infection severity remains unclear. This study examined RSV infection severity and hospitalization outcomes in Japanese infants and children according to palivizumab eligibility and identified their associated factors. METHODS: Using insurance claims data from 12 municipalities, we identified RSV cases aged ≤24 months between April 2017 and March 2022. The patients' characteristics and hospitalization status were analyzed according to the presence of palivizumab-indicated underlying conditions. Regression models were used to identify factors associated with hospitalization, length of stay (LOS), and hospital expenditures. RESULTS: We analyzed 1025 first-time RSV cases (860 infants <12 months and 165 children 12-24 months old). There were 777 (90.3%) palivizumab-ineligible infants and 83 (9.7%) palivizumab-eligible infants. Only 13 (15.7%) palivizumab-eligible infants had received palivizumab in the month before RSV infection, and 8 required hospitalization. RSV hospitalization was significantly associated with age (odds ratio: 0.84, 95% confidence interval: 0.79-0.88), palivizumab-indicated underlying conditions (1.82, 1.13-2.89), and non-indicated high-risk conditions (4.87, 2.28-10.99). These factors were also associated with LOS. Hospital expenditures were associated with age, high-risk conditions and LOS. CONCLUSIONS: Palivizumab-indicated underlying conditions, high-risk conditions, and younger age are risk factors for RSV hospitalization. Most hospitalized patients did not receive palivizumab in the month before RSV infection despite being eligible, suggesting that some hospitalizations were preventable through appropriate palivizumab use.

Association between regular physical activity and pneumonia-related hospitalization according to pneumococcal vaccination status: The VENUS study.

BACKGROUND: Little is known about the impact of physical activity (PA) and PPSV23 vaccination on pneumonia-related hospitalizations. This study examined the association between regular PA and pneumonia-related hospitalization according to PPSV23 vaccination status in older adults. METHODS: This retrospective cohort study was conducted using health checkup data, medical care claims data, and vaccination records from two Japanese municipalities. Residents aged ≥65 years who had undergone a health checkup between April 2016 and March 2021 were categorized into a PPSV23 vaccinated or unvaccinated cohort. Each cohort was further divided into a PA group and no PA group. The hazard ratio (HR) of PA for pneumonia-related hospitalization was calculated for each cohort while adjusting for sex, age, comorbidities, and metabolic syndrome. RESULTS: The vaccinated cohort comprised 16,295 participants (no PA: 5,139, PA: 11,156), and the unvaccinated cohort comprised 7,998 participants (no PA: 2,671, PA: 5,327). In the vaccinated cohort, the PA group had a significantly lower hazard for pneumonia-related hospitalization than the no PA group (adjusted HR: 0.58, P = 0.004). However, PA was not associated with pneumonia-related hospitalization in the unvaccinated cohort (adjusted HR: 0.70, P = 0.270). CONCLUSIONS: PA can reduce the risk of pneumonia-related hospitalization in vaccinated persons. Interventions that increase both vaccination rates and PA habits may help to reduce these hospitalizations in older adults.

Investigating the epidemiology and outbreaks of scabies in Japanese households, residential care facilities, and hospitals using claims data: the Longevity Improvement & Fair Evidence (LIFE) study.

Objectives: This study aimed to characterize the epidemiology of scabies and its outbreaks in Japanese households, residential care facilities (RCFs), and hospitals using claims data. Methods: This descriptive epidemiological study was conducted using claims data from eight municipalities in Japan. Scabies cases were identified using a combination of recorded diagnoses and administered medications. The study period was from April 2015 to March 2019. Outbreaks were defined as ≥2 cases of scabies occurring within a calendar month at a single household, RCF, or hospital. Results: We identified 857 scabies cases for analysis. The annual prevalence of scabies ranged from 40 to 67 per 100,000 beneficiaries. The annual attack rate of scabies was found to be highest in RCFs (21 per 1000 RCFs), followed by hospitals (11 per 1000 hospitals) and households (0.25 per 1000 households). The annual outbreak attack rate was also highest in RCFs (4.0 per 1000 RCFs), followed by hospitals (1.6 per 1000 hospitals) and household (0.027 per household). The patterns of outbreaks varied widely among the RCFs. Conclusions: The study showcases the potential of claims data for detecting infectious disease outbreaks, which could provide valuable insight for the future management and prevention of scabies. Infection control of scabies in RCFs is crucial in aging societies.

Risk of pneumonia-related hospitalization after initiating angiotensin-converting enzyme inhibitors compared with angiotensin II receptor blockers: a retrospective cohort study using LIFE Study data.

There is insufficient evidence that angiotensin-converting enzyme inhibitors (ACEIs) can reduce pneumonia by inducing a dry cough that confers a protective effect on the airway. To increase the evidence base on the clinical use of ACEIs for pneumonia prevention, this retrospective cohort study aimed to comparatively examine the risk of pneumonia-related hospitalization between ACEI initiators and angiotensin II receptor blocker (ARB) initiators using claims data from two Japanese municipalities. We identified persons who were newly prescribed any ACEI or ARB as their first antihypertensive agent between April 2016 and March 2020. The Fine-Gray method was applied to a Cox proportional hazards model to estimate the subdistribution hazard ratio (HR) of ACEI use (reference: ARB use) for pneumonia-related hospitalization, with death treated as a competing risk. Sex, age, comorbidities, medications, and pneumococcal immunization were included as covariates. The analysis was conducted on 1421 ACEI initiators and 9040 ARB initiators, and the adjusted subdistribution HR of ACEI use was estimated to be 1.21 (95% confidence interval: 0.89-1.65; P = 0.22). ACEI initiation did not demonstrate any significant preventive effect against pneumonia-related hospitalization relative to ARB initiation. There remains a lack of strong evidence on the protective effects of ACEIs, and further research is needed to ascertain the benefits of their use in preventing pneumonia. We conducted a large-scale retrospective cohort study using real-world healthcare data from a Japanese population. In this study, ACEI initiation did not indicate a significant preventive effect against pneumonia-related hospitalization.

Medication adherence and associated factors in newly diagnosed hypertensive patients in Japan: the LIFE study.

Hypertension is the leading cardiovascular risk factor worldwide. However, in Japan, only 30% of patients have their blood pressure controlled under 140/90 mmHg, and nonadherence to antihypertensives is thought to be a reason for the poor control of hypertension. We therefore sought to assess the adherence to hypertension treatment and to evaluate factors influencing patients' adherence in a large, representative sample of the Japanese population. To this end, we analyzed claims data from the LIFE Study database, which includes 112 506 Japanese adults with newly diagnosed hypertension. Medication adherence was measured for a year postdiagnosis using the proportion of days covered (PDC) method. Factors associated with adherence to antihypertensives were also assessed. Among the total 112 506 hypertensive patients, the nonadherence rate (PDC ≤ 80%) for antihypertensives during the first year after initiation of the treatment was 26.2%. Younger age [31-35 years: odds ratio (OR), 0.15; 95% confidence interval (95% CI), 0.12-0.19 compared with 71-74-year-old patients], male gender, monotherapy, and diuretics use [OR, 0.87; 95% CI, 0.82-0.91 compared with angiotensin II receptor blockers (ARBs)] were associated with poor adherence in the present study. Cancer comorbidity (OR, 0.84; 95% CI, 0.79-0.91 compared with no comorbidity), prescription at a hospital, and living in a medium-sized to regional city were also associated with poor adherence. Our present findings showing the current status of adherence to antihypertensive medications and its associated factors using claims data in Japan should help to improve adherence to antihypertensives and blood pressure control.

Association between mRNA COVID-19 vaccine boosters and mortality in Japan: The VENUS study.

Although previous studies have shown no increased mortality risk after the primary series of COVID-19 mRNA vaccines, reports on booster doses are lacking. This study aimed to evaluate mortality risk after the mRNA vaccine boosters in addition to the primary series. This nested case-control study included two age-specific cohorts (18-64 and ≥65 years as of February 1, 2021) in two municipalities. All deaths were identified and matched five controls for each case at each date of death (index date) with risk set sampling according to municipality, age, and sex. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for mRNA vaccines (first to fifth doses) were estimated by comparing with no vaccination within 21 and 42 days before the index date using a conditional logistic regression model. The 18-64-years cohort comprised 431 cases (mean age, 57.0 years; men, 58.2%) and 2,155 controls (mean age, 56.0; men, 58.2%), whereas the ≥65-years cohort comprised 12,166 cases (84.0; 50.2%) and 60,830 controls (84.0, 50.2%). The aORs (95% CI) in 0-21 days after the third and fourth doses in the 18-64-years cohort were 0.62 (0.24, 1.62) and 0.38 (0.08, 1.84), respectively. The aORs (95% CI) after the third to fifth doses in the ≥65 years cohort were 0.36 (0.31, 0.43), 0.30 (0.25, 0.37), and 0.26 (0.20, 0.33), respectively. In conclusion, booster doses of mRNA vaccines do not increase mortality risk. These findings could help subsequent vaccine campaigns and alleviate vaccine hesitancy.

Incidence of post-COVID psychiatric disorders according to the periods of SARS-CoV-2 variant dominance: The LIFE study.

This retrospective cohort study examined the incidence of post-COVID psychiatric disorders in older adults according to hospitalization status and SARS-CoV-2 variant period in Japan. Claims data, COVID-19 case-related information, and vaccination records were obtained from three Japanese municipalities. We identified individuals aged ≥65 years who had COVID-19 or other respiratory tract infection (RTI) between March 2021 and December 2022. Participants were categorized into non-hospitalized and hospitalized patients, and the study period was divided into the Alpha (March to May 2021), Delta (June to December 2021), Omicron BA.1/BA.2 (January to June 2022), and Omicron BA.5 (July to December 2022) periods. Modified Poisson regression analyses were performed to estimate the incidence rate ratios (IRRs) for the occurrence of psychiatric disorders (organic mental disorders, psychotic disorders, mood disorders, anxiety disorders, and insomnia) three months after COVID-19 (reference: other RTI). For overall psychiatric disorders, we analyzed 19,489 non-hospitalized patients (COVID-19: 6,728, Other RTI: 12,761) and 2925 hospitalized patients (COVID-19: 1,036, Other RTI: 1889). When compared with other RTI cases, COVID-19 cases had significantly lower IRRs for overall psychiatric disorders in both non-hospitalized (IRR: 0.59, P < 0.001) and hospitalized cases (IRR: 0. 83, P = 0.045) during the Omicron BA.1/BA.2 period, but only in non-hospitalized cases (IRR: 0.45, P < 0.001) during the Omicron BA.5 period. The incidences of the individual post-COVID psychiatric disorders varied according to disorder type, hospitalization status, and SARS-CoV-2 variant period. These findings provide a foundation for further research to explore these variations and improve the provision of psychiatric care in future epidemics.