JOURNAL OF EPIDEMIOLOGY

Prevalence, incidence, and recovery of metabolic dysfunction-associated steatotic liver disease and associations with weight loss and lipid reduction in a Chinese community-based cohort
Xu Y, Wang Y, Yao X, Zhao Q, Chen B, Wang N, Zhang T, Jiang Y, Wu Y, He N, Zhao G, Sun Z and Liu X
As the most common chronic liver disease worldwide, the natural history of metabolic dysfunction-associated steatotic liver disease (MASLD) in general population is barely reported.
News coverage of older drivers' fatal car crashes: is it over-represented?
Ichikawa M, Tanaka R, Nakanishi A and Sano Y
Japan's stringent licensing policies for older drivers have not been questioned, possibly due to negative perceptions of older drivers potentially influenced by media coverage of their car crashes. We examined whether older drivers' fatal crashes are over-represented in the news articles.
Comparison of Demographic and Clinical Characteristics of Taiwan Biobank Participants with Nonparticipants
Wu CS, Hsu LY, Shen CY, Chen WJ, Lin MC, Fan CC and Wang SH
This study investigated fundamental demographic variables within the Taiwan Biobank (TWBB) and compared them with national demographic statistics. Additionally, a matched cohort analysis compared TWBB participants with nonparticipants to uncover disparities in sociodemographic and clinical characteristics.
Changes in mortality during the COVID-19 pandemic in Japan: descriptive analysis of national health statistics up to 2022
Tanaka H, Nomura S and Katanoda K
Amidst the global coronavirus disease (COVID-19) pandemic, Japan has faced a significant public health challenge, evident from the significant increase in mortality rates since 2021. This study described the variations in all-cause and cause-specific changes in mortality up to 2022 in Japan.
Estimating the prevalence of and clarifying factors associated with multiple tobacco product use in Japan: a cross-sectional study in 2022
Yamamoto T, Abbas H, Cooray U, Yokoyama T and Tabuchi T
BackgroundMultiple tobacco product (MTP) use is a public health concern due to their combined adverse health effects. MTP use may have increased since heated tobacco products (HTPs) became more prevalent in Japan. This study aimed to (1) estimate the recent prevalence of MTP use and clarify the associated factors compared to (2) non-smokers and (3) single-product users.MethodWe used data from an internet survey conducted in February 2022. The prevalence of MTP use in Japan was estimated using inverse probability-weighted scores from this survey and a nationwide survey by the Japanese government. Tobacco products include six types: cigarettes, HTPs, e-cigarettes, cigars, pipe/water pipes, and smokeless tobacco products. MTP use was defined using the outcome variable (no use, single-product use, and MTP use) based on these six types of use. Using multivariate logistic regression, we calculated the adjusted odds ratios and 95% confidence intervals (CI) to clarify factors associated with MTP use compared to non-smokers, adjusting demographic variables, psychological distress, self-rated health, and alcohol use. Using multivariate Poisson regression, we calculated the adjusted prevalence ratios (aPR) and 95%CI to clarify factors associated with MTP use among smokers, adjusting for these covariates and smoking-related factors like workplace and home smoking rules.ResultsWe analyzed 30,141 participants whose mean age was 47.8 years (standard deviation = 17.9), and 14,722 participants were male (48.8%). The estimated prevalence of MTP use was 6.8%. The most common combination of MTP use was cigarettes and HTPs. Compared to non-smokers, being younger, male, low education, poor psychological distress, poor self-rated health, and alcohol use were factors associated with MTP use. Among smokers, workplace smoking rules, such as a partial smoking ban and no smoking ban, were not associated with MTP use compared to the indoor smoking ban. However, participants with no home smoking ban were positively associated with MTP use compared to those with a ban on both cigarettes and HTPs at home (both cigarettes and HTPs allowed aPR=1.36, 95%CI 1.15 to 1.61, HTPs only allowed aPR=1.73, 95%CI 1.43 to 2.10).ConclusionMTP users may account for a high percentage of Japanese smokers.
Regional variations and inequalities in testing for early detection of breast and cervical cancer: evidence from a nationally representative survey in India
Rahman MM, Rahman MS, Islam MR, Gilmour S, Haruyama R, Budukh A, Shankar A, Mishra G, Mehrotra R, Matsuda T, Inoue M and Abe SK
The burden of cancer in India has been rising, yet testing for early detection remains low. This study explored inequalities in the uptake of breast cancer (BC) examination and cervical cancer (CC) among Indian women, focusing on socioeconomic, regional, and educational differences.
When and how to split the follow-up time in the analysis of epidemiological or clinical studies with follow-ups
Iwagami M, Ishimaru M, Takeuchi Y and Shinozaki T
In epidemiological or clinical studies with follow-ups, data tables generated and processed for statistical analysis are often of the "wide-format" type-consisting of one row per individual. However, depending on the situation and purpose of the study, they may need to be transformed into the "long-format" type-which allows for multiple rows per individual. This tutorial clarifies the typical situations wherein researchers are recommended to split follow-up times to generate long-format data tables. In such applications, the major analytical aims consist of (i) estimating the outcome incidence rates or their ratios between ≥ 2 groups, according to specific follow-up time periods; (ii) examining the interaction between the exposure status and follow-up time to assess the proportional hazards assumption in Cox models; (iii) dealing with time-varying exposures for descriptive or predictive purposes; (iv) estimating the causal effects of time-varying exposures while adjusting for time-varying confounders that may be affected by past exposures; and (v) comparing different time periods within the same individual in self-controlled case series analyses. This tutorial also discusses how to split follow-up times according to their purposes in practical settings, providing example codes in Stata, R, and SAS.
Can cessation of caregiving for parents relieve family caregivers' psychological distress? A longitudinal study using 17-wave nationwide survey data in Japan
Oshio T and Ping R
Informal caregiving of older parents adversely affects the mental health of family caregivers. However, the psychological effects of caregiving cessation and the trajectories of these effects have rarely been examined in Japan. This study addresses this gap.
Associations of parental education with children's infectious diseases and their mediating factors: the Japan Environment and Children's Study (JECS)
Narita M, Yamamoto M, Sakurai K, Mori C and
BackgroundParents' educational background is presumed to influence the incidence of vaccine-preventable diseases in children through their decisions about vaccinations and other family lifestyle choices. Regarding voluntary vaccination, a household's economic situation may also be associated with non-vaccination. Therefore, this study investigated the association between parental education and vaccine-preventable diseases (varicella, mumps, influenza [flu], pertussis, measles, and rubella) in children, which currently remains elusive.MethodsWe used datasets from the Japan Environment and Children's Study, which included 104,062 fetal records; our study population comprised 80,930 children up to the age of three years. The associations between parental educational background and children's infectious diseases were examined using binomial logistic regression analysis. The mediating effects of household income, vaccination, and smoking were examined using a path analysis.ResultsFor varicella, mumps, and influenza covered by voluntary vaccination, a higher education level of the father was associated with a lower incidence of infection. The association between mothers' education and children's infection was limited. There were both income-mediated and non-income-mediated pathways between parental education and voluntary vaccination. For pertussis, measles, and rubella, which are covered by routine vaccines, there was no association between parental education and the child's infection.ConclusionAn association between parental education and childhood infections was observed. Additionally, providing financial support for vaccination and communicating the benefits of vaccination in a way that parents at all levels of education can understand will help reduce the incidence of infectious diseases among children.
Sentinel surveillance of COVID-19: the importance of epidemiologic concepts and reasoning
Arima Y, Takahashi T, Kasamatsu A, Arashiro T, Kobayashi Y, Otsuka M, Takahara O, Shimbashi R, Komase K, Kamigaki T and Suzuki M
Validity and reproducibility of food group intakes in a self-administered food frequency questionnaire for genomic and omics research: the Tohoku Medical Megabank Project
Murakami K, Ishihara J, Takachi R, Sugawara S, Aizawa M, Takahashi I, Obara T, Ishikuro M, Noda A, Ogino M, Hoshina Y, Kito K, Nakadate M, Maruya S, Matsuno T, Yonezawa Y, Yamashita T, Suzuki S, Yamamoto M and Kuriyama S
The Tohoku Medical Megabank Project (TMM) was established to realize personalized healthcare and medicine using genomic and omics data. This study evaluated the validity and reproducibility of food group intakes derived from a self-administered food frequency questionnaire (TMM-FFQ) that included the response option "constitutionally unable to eat/drink it" among community-dwelling Japanese adults.
Seasonal variation in the intake of food groups and nutrients in Japan: A systematic review and meta-analysis
Adachi R, Oono F, Matsumoto M, Yuan X, Murakami K, Sasaki S and Takimoto H
Background Seasonal variations could systematically bias dietary intakes. This systematic review aimed to determine seasonal variations in dietary intake among Japanese adults.Methods PubMed and Ichushi-Web databases were searched for studies reporting seasonal intakes of nutrients or food groups assessed by dietary records or 24-hour recalls. The protocol was registered with PROSPERO (CRD42022356084).Results Ten studies (eight studies on 1-31 nutrients and four on 2-15 food groups) met the inclusion criteria. Six studies included both sexes, whereas four investigated only females. The number of participants ranged from 25 to 459, and the number of dietary survey days in each season ranged from 1 to 14. For most nutrient and food groups, the reported seasonal variations were inconsistent across studies. The meta-analyses comparing differences in mean intakes between two seasons showed no significant differences in all comparisons or differences in only one comparison for most nutrients and food groups. Significant seasonal differences were observed for vegetables, fruits, and potatoes in five out of six comparisons, though the heterogeneity was high. Their biggest differences were as follows: 101 g/day more vegetable intake in summer than spring, 60 g/day more fruit intake in fall than spring, and 20.1 g/day more potato intake in fall than spring.Conclusion Reported seasonal variations were inconsistent across studies for most food groups and nutrients. Relatively distinct seasonal differences in mean intakes were observed for vegetables, fruits, and potatoes in meta-analyses. However, these results must be interpreted cautiously because of the high heterogeneity and limited representativeness.
Development of a Brief Assessment Tool to Evaluate Early Low Nutrition Risk in Community Elderly. Creation of the tool and examination of its reliability and criterion-related validity
Shoji S, Narita M, Murayama H, Kitamura A and Fujiwara Y
To date simple assessment tool to evaluate early low nutrition risk in general older population has not been available. This study aimed to create such tool and examined its reliability and criterion-related validity.
Causal mediation analyses for the natural course of hepatitis C: a prospective cohort study
Huang YT, Hsu YC, Yang HI, Lee MH, Lai TH, Chen CJ and Huang YT
BackgroundHepatitis C virus (HCV) infection is a systemic disease. However, the relative contribution of intrahepatic and extrahepatic diseases to mediating HCV-induced mortality is unclear, albeit critical in resource allocation for reducing preventable deaths. To this end, this study comprehensively quantified the extent to which intrahepatic and extrahepatic diseases mediate HCV-induced mortality.MethodsA community-based cohort study with >25 years of follow-up was conducted in Taiwan. HCV infection was profiled by antibodies against HCV and HCV RNA in participants' serum samples. The cohort data were linked to Taiwan's National Health Insurance Research Database to determine the incidences of potential mediating diseases and mortality. We employed causal mediation analyses to estimate the mediation effects of HCV on mortality in relation to the incidences of 34 candidate diseases.ResultsIn 18,972 participants with 934 HCV infection, we observed that 54.1% of HCV-induced mortality was mediated by intrahepatic diseases, such as liver cirrhosis and liver cancer, and 45.9% of mortality was mediated by extrahepatic diseases. The major extrahepatic mediating diseases included septicemia (estimated proportion of HCV-induced mortality mediated through the disease: 25.2%), renal disease (16.7%), blood/immune diseases (12.2%), gallbladder diseases (9.7%), and endocrine diseases (9.6%). In women, hypertension (20.0%), metabolic syndrome (18.9%), and type 2 diabetes (17.0%) also mediated HCV-induced mortality. A dose-response relationship of HCV viral load was further demonstrated for the mediation effect.ConclusionBoth intrahepatic and extrahepatic manifestations mediated approximately a half of HCV-induced mortality. The mediation mechanisms are supported by a dose-response relationship of HCV viral load.
Non-cancer-related Deaths in Cancer Survivors: A Nationwide Population-Based Study in Japan
Gon Y, Zha L, Morishima T, Kimura Y, Asai K, Kudo H, Sasaki T, Mochizuki H, Miyashiro I and Sobue T
Advancements in cancer care have improved survivorship, potentially leading to changes in mortality causes. This study aimed to investigate the causes of death among cancer survivors, specially focusing on non-cancer-related mortality.
Enhancing the Understanding of Paternal Involvement in Childcare and Its Impact on Maternal Disciplinary Practices
Pan H
Body Mass Index, Height and Head and Neck Cancer Risk: the Japan Public Health Center-based Prospective Study
Suzuki S, Yamaji T, Iwasaki M, Inoue M, Tsugane S, Shinozaki T and Sawada N
Although both a lower and a higher body mass index (BMI) are reportedly associated with head and neck cancer (HNC), reports from Asia are scarce. Moreover, evidence regarding the association between height and HNC is limited.
Mortality after partner's cancer diagnosis or death: A population-based prospective cohort study in Japan
Makiuchi T, Kakizaki M, Sobue T, Kitamura T, Yatsuya H, Yamaji T, Iwasaki M, Inoue M, Tsugane S and Sawada N
The health statuses of closely connected individuals are interdependent. Little is known about mortality risk associated with partner's cancer diagnosis and cause-specific mortality risk associated with partner's death.
Much lower prevalence and mortality of chronic obstructive pulmonary disease in Japan than in the US despite higher smoking rates: A meta analysis/systematic review
Sekikawa A, Li M, Joshi N, Herbert B, Tilves C, Cui C, Gao S, Chang Y, Nakano Y and Sciurba FC
A recent systematic review showed Japan's mortality from chronic obstructive pulmonary disease (COPD) is the lowest among 204 countries, despite notably higher smoking rates in men in Japan than in the US. This study aims to compare (1) trends in smoking rates, (2) trends in COPD mortality, and (3) the spirometry-based COPD prevalence in the general adult population between Japan and the US.
Validation of self-reported medical condition in the Taiwan Biobank
Wu CS, Hsu LY, Shen CY, Chen WJ and Wang SH
This study aimed to validate self-reported medical conditions in the Taiwan Biobank (TWBB), in which participants were inquired about 30 disease conditions, by comparing them with claims records from Taiwan's National Health Insurance (NHI) claims database.
Association between maternal physical activity from pre-pregnancy to child-rearing and their children's physical activity in early childhood among Japanese
Yamada A, Momma H, Tatsuta N, Nakai K, Arima T, Ota C, Yaegashi N and Nagatomi R
This study aimed to determine the association between cumulative maternal physical activity level and their children's physical activity in early childhood. We also compared the influence of each maternal physical activity on children's physical activity in early childhood.