Eri Maeda

Estimation of the number of children with cerebral palsy using nationwide health insurance claims data in Japan.

Japan lacks a population‐based registration system for cerebral palsy (CP), therefore the nationwide prevalence of CP is unknown. Our aim was to estimate the number of children with CP using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, which has been recently developed by the government.

Effects of work stress and home stress on autonomic nervous function in Japanese male workers

Autonomic imbalance is one of the important pathways through which psychological stress contributes to cardiovascular diseases/sudden death. Although previous studies have focused mainly on stress at work (work stress), the association between autonomic function and stress at home (home stress) is still poorly understood. The purpose was to clarify the effect of work/home stress on autonomic function in 1,809 Japanese male workers. We measured corrected QT (QTc) interval and QT index on the electrocardiogram along with blood pressure and heart rate. Participants provided self-reported information about the presence/absence of work/home stress and the possible confounders affecting QT indicators. Home stress was related positively to QT index (p=0.040) after adjusting for the possible confounders, though work stress did not show a significant relation to QTc interval or QT index. The odds ratio of home stress to elevated QT index (≥105) was 2.677 (95% CI, 1.050 to 6.822). Work/home stress showed no significant relation to blood pressure or heart rate. These findings suggest that autonomic imbalance, readily assessed by QT indicators, can be induced by home stress in Japanese workers. Additional research is needed to identify different types of home stress that are strongly associated with autonomic imbalance.

Cesarean section rates and local resources for perinatal care in Japan: A nationwide ecological study using the national database of health insurance claims

High cesarean section (CS) rates in middle and high‐income countries are partly attributable to provider factors, such as staffing patterns and fear of litigation. However, the relationship between CS rates and healthcare resources in the community is poorly understood. Official data on CS rates has been particularly limited in Japan. In this study, we examined nationwide CS statistics and evaluated the association with local resources for perinatal care.

Age-specific cost and public funding of a live birth following assisted reproductive treatment in Japan.

The aim of this study was to calculate and assess the cost of assisted reproductive technology (ART) treatment cycles and live‐birth events in Japan in 2010.

The Association between Work-Related Stress and Autonomic Imbalance among Call Center Employees in Japan

There is little epidemiological evidence linking subjective stress to objective etiologic indicators. To clarify an association between work-related stress and autonomic nervous function, we examined call center employees (167 males and 371 females) undergoing electrocardiography (ECG) at the time of annual health checkups. The questionnaire was composed of the Brief Job Stress Questionnaire based on the demand-control-support model and the Social Readjustment Rating Scale including detailed contents of home stress. The Bazetts corrected QT (QTc) interval, QT index, and heart rate were obtained from the ECG data. The male employees showed significantly higher scores of job demand, job control, and supervisor support than the female ones. In the male employees, QT index indicating the extent of autonomic imbalance and heart rate were associated with high score of supervisor support and low score of coworker support (P < 0.05), but no significant relationships were seen between QTc interval and either job strain (i.e., job demand and job control) or home stress. By contrast, the female employees showed no significant links between any autonomic indicators and either work-related stress or home stress. These data suggest that work-related stress affected QT index in male employees suffering specific occupational stressors such as emotional abuse from unsatisfied customers. Specifically, supports from supervisors and coworkers were paradoxically associated with QT index, implying that supervisors may have failed to effectively support such male employees. Also, autonomic nervous function in male employees appears to be more vulnerable to work-related stress than that in female ones.

Precarious Employment Is Not Associated with Increased Depressive Symptoms: A Cross-Sectional Study in Care Service Workers of Japan

Some epidemiological studies with a large number of subjects, like a national health study, reported that precarious employment was associated with increased depressive symptoms, but this hypothesis may not be applicable to precarious workers of all industry types. We examined the association between precarious employment and depressive symptoms in light of work-related stress in care work environments. The self-administered questionnaire, composed of the Job Content Questionnaire based on the demand-control-support model and the Center of Epidemiological Studies Depression Scale (CES-D), was distributed, and a total of 1,338 permanent and 531 precarious employees responded to it with complete forms. In the precarious employees, scores of CES-D, job demand and job control were lower and supervisor support score was higher compared with the permanent employees, though there was no significant difference in the proportion of CES-D score ≥16 between the two groups. Multivariate analysis with adjustment for possible confounders revealed that increased depressive symptoms were associated with low coworker support in the precarious employees and with high demand and low control at work, low support from supervisors and coworkers in the permanent employees. However, precarious employment was not significantly associated with depressive symptoms in the male or female employees. In conclusion, our results do not support the above hypothesis at least in care service workers. Such a hypothesis should be verified in employees of each industry separately. Instead, coworker support within each workplace appears to be important for the preventive strategy of depression in workers including precarious employees.

Assessment of Cardiac Autonomic Function in Relation to Methylmercury Neurotoxicity

After the European Food Safety Authority reviewed reports of methylmercury and heart rate variability (HRV) in 2012, the panel concluded that, although some studies of cardiac autonomy suggested an autonomic effect of methylmercury, the results were inconsistent among studies and the implications for health were unclear. In this study, we reconsider this association by adding a perspective on the physiological context. Cardiovascular rhythmicity is usually studied within different frequency domains of HRV. Three spectral components are usually detected; in humans these are centered at <0.04 Hz, 0.15 Hz (LF), and 0.3 Hz (HF). LF and HF (sympathetic and parasympathetic activities, respectively) are evaluated in terms of frequency and power. By searching PubMed, we identified 13 studies examining the effect of methylmercury exposure on HRV in human populations in the Faroe Islands, the Seychelles and other countries. Considering both reduced HRV and sympathodominant state (i.e., lower HF, higher LF, or higher LF/HF ratio) as autonomic abnormality, eight of them showed the significant association with methylmercury exposure. Five studies failed to demonstrate any significant association. In conclusion, these data suggest that increased methylmercury exposure was consistently associated with autonomic abnormality, though the influence of methylmercury on HRV (e.g., LF) might differ for prenatal and postnatal exposures. The results with HRV should be included in the risk characterization of methylmercury. The HRV parameters calculated by frequency domain analysis appear to be more sensitive to methylmercury exposure than those by time domain analysis.

Dilemma of Environmental Health Research

This article presents not only a brief overview of birth cohort studies focusing on environmental health in which the associations between health and environment were examined, but also a tentative plan to apply epidemiological data to benchmark dose calculation. According to the preceding studies, the checkpoints to be scrutinized when a result is not consistent with those of other researchers are as follows: (1) whether the study included all crucial confounders, (2) whether it included any exposure marker or confounder with a U-shaped dose-response curve, (3) whether the outcome measure was conducted by two or more examiners that might lead to measurement bias, (4) whether such examiners picked up information about exposure levels of the subjects before measuring the endpoints, and (5) whether subjects with different genetic factors were included in the analysis. In addition, (6) researchers conducting a childrens study on developmental effects due to toxic substances must keep in mind that the impact of prenatal methylmercury exposure, independent of postnatal exposure, may continue for at least seven years. (7) When an environmental health research emphasizes to be population-based study, the levels of exposure to environmental chemical substances in developed countries with strict environmental regulations may be too low to examine a dose-response relationship for critical dose estimation. Such risk assessment should be carried out among the subjects with a wide range of exposure levels.

Two-year follow-up of a randomised controlled trial: knowledge and reproductive outcome after online fertility education

Abstract STUDY QUESTION What are the long-term effects of fertility education on knowledge and reproductive outcome? SUMMARY ANSWER Participants in the intervention group retained some knowledge after 2 years and the partnered women had a new child more quickly than the comparison group. WHAT IS KNOWN ALREADY Fertility education improves knowledge, at least in the short-term. Attitudes toward childbearing and its timing can change after exposure to educational materials. STUDY DESIGN, SIZE, DURATION Participants were recruited via an online social research panel. In the original randomized controlled trial (RCT), knowledge of reproductive-aged participants was assessed before (T1) and immediately after (T2) receiving one of three information brochures: fertility (intervention group), healthy pre-pregnancy (focused on intake of folic acid during pregnancy, control group 1), or family policies in Japan (childcare provision, control group 2). The present follow-up study was conducted 2 years later in January 2017 (T3) with the same participants. PARTICIPANTS/MATERIALS, SETTING, METHODS Of the T1 participants (n = 1455), 383 men and 360 women (51%) responded to the T3 survey. Fertility knowledge measured with the Japanese version of the Cardiff Fertility Knowledge Scale (CFKS-J) and fertility status (e.g. new births, new medical consultations, and the timing of new birth) was assessed. MAIN RESULTS AND THE ROLE OF CHANCE Baseline (T1) characteristics of the T3 participants were well balanced between groups, but T3 participants were older, married, and more educated compared to those lost to follow-up. A repeated-measures analysis of variance showed significant knowledge gains among the intervention group from T1 to T3 (11.2% and 7.0% among men and women, respectively) but no significant change over time for the control groups. There were no differences between groups in the incidence of new births or new medical consultations. However, subgroup analysis showed that timing of new births was accelerated for partnered individuals in the intervention group. Specifically, the proportion of partnered participants at T1 who had a new birth in the first year subsequent to presentation of information was higher in the intervention group versus control group 1 (folic acid): 8.8% versus 1.4% (P = 0.09) among men and 10.6% versus 2.3% (P = 0.03) among women, respectively. The odds ratios (adjusted for age) were 7.8 (95% CI: 0.86–70.7) and 5.2 (95% CI: 1.09–25.0) among men and women, respectively. The timing of births and the proportion of new births during the 2-year follow-up period in the intervention group were similar to that of control group 2 (family policy). The incidence of new medical consultation was higher in the male intervention group (12.0%) than in male control group 2 (family policy, 1.5%, P = 0.04) but similar among women in all groups. LIMITATIONS REASONS FOR CAUTION First, the high attrition rate may limit the generalizability of these findings for longer-term acquisition of fertility knowledge, especially when applied to younger people who were more likely to be lost to follow-up. Second, this is a 2-year follow-up study and the results may change in the longer-term. Finally, we relied on self-reported questionnaire data and there is a possibility that some women were unknowingly pregnant at T1 but this risk should be distributed equally in the three groups through randomization. WIDER IMPLICATIONS OF THE FINDINGS Effects of one-time education were limited but retained beyond baseline levels. Importantly, education was found to potentially accelerate decision-making about achieving births in partnered subgroups compared to receiving healthy pre-pregnancy information. However, this finding should be confirmed in future stratified RCTs designed to evaluate effects in these subgroups. Follow-up ‘booster’ education sessions might help people retain knowledge and facilitate reproductive decisions for longer. In view of the high attrition rate, especially among young populations, novel educational strategies to retain young people in fertility education cohorts should be explored. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by National Center for Child Health and Development, the Daiwa Anglo-Japanese Foundation, Pfizer Health Research Foundation, and the Japan Society for the Promotion of Science. E.M. reports joint research funds from a public interest incorporated foundation ‘1 more Baby Ohendan.’

Appropriateness of the institute certification system for esophageal surgeries by the Japan Esophageal Society: evaluation of survival outcomes using data from the National Database of Hospital-Based Cancer Registries in Japan

BackgroundSince 2013, The Japan Esophageal Society has been certifying “Authorized Institute for Board Certified Esophageal Surgeon (AIBCES)” to contribute to improving national medical care by enhancing the professional knowledge and skills of esophageal surgeons. However, the appropriateness on this certification system has not yet been verified. Our aim was to assess the appropriateness of the institute certification system for esophageal surgeries used by the medical society.MethodsUsing data from the National Database of Hospital-based Cancer Registries, we analyzed the 5-year overall survival rates among 2135 patients with thoracic esophageal cancer who underwent an esophagectomy at 53 AIBCES or 141 non-AIBCES.ResultsThere were 1343 (63%) patients who underwent surgery at an AIBCES and 792 (37%) who underwent surgery at a non-AIBCES. Registered patients were followed up for a median of 53 (range 1–88) months. Over the followed-up period examined, 670 (50%) patients treated at an AIBCES died and 455 (57%) treated at a non-AIBCES died. Comparison of the Kaplan–Meier survival curves indicated that patients with cStage II or cStage III disease treated at an AIBCES had significantly better 5-year survival rates than those treated at a non-AIBCES (55.4% vs. 44.9% and 38.0% vs. 30.3%, respectively). Univariate and multivariate analyses stratified based on stages and adjuvant therapies revealed that institute certification (AIBCES vs. non-AIBCES) is a significant independent factor for 5-year survival.ConclusionsThe institute certification system used by the Japan Esophageal Society may be appropriate, as indicated by improved 5-year survival outcomes. The institute certification system has the potential to contribute to a more appropriate medical delivery system in the future.