Working hours of full-time hospital physicians in Japan: a cross-sectional nationwide survey.

BACKGROUND: The culture of excessively long overtime work in Japan has not been recently addressed. New legislation on working hours, including a limitation on maximum overtime work for physicians, will be enforced in 2024. This study was performed to elucidate the working conditions of full-time hospital physicians and discuss various policy implications. METHODS: A facility survey and a physician survey regarding physicians' working conditions were conducted in July 2022. The facility survey was sent to all hospitals in Japan, and the physician survey was sent to all physicians working at half of the hospitals. The physicians were asked to report their working hours from 11 to 17 July 2022. In addition to descriptive statistics, a multivariate logistic regression analysis on the factors that lead to long working hours was conducted. RESULTS: In total, 11,466 full-time hospital physicians were included in the analysis. Full-time hospital physicians worked 50.1 h per week. They spent 45.6 h (90.9%) at the main hospital and 4.6 h (9.1%) performing side work. They spent 43.8 h (87.5%) on clinical work and 6.3 h (12.5%) on activities outside clinical work, such as research, teaching, and other activities. Neurosurgeons worked the longest hours, followed by surgeons and emergency medicine physicians. In total, 20.4% of physicians were estimated to exceed the annual overtime limit of 960 h, and 3.9% were estimated to exceed the limit of 1860 h. A total of 13.3% and 2.0% exceeded this level only at their primary hospital, after excluding hours performing side work. Logistic regression analysis showed that male, younger age, working at a university hospital, working in clinical areas of practice with long working hours, and undergoing specialty training were associated with long working hours after controlling for other factors. CONCLUSIONS: With the approaching application of overtime regulations to physicians, a certain reduction in working hours has been observed. However, many physicians still work longer hours than the designated upper limit of overtime. Work reform must be further promoted by streamlining work and task-shifting while securing the functions of university hospitals such as research, education, and supporting healthcare in communities.

Differences in the components of metabolic syndrome by age and sex: a cross-sectional and longitudinal analysis of a cohort of middle-aged and older Japanese adults.

BACKGROUND: The prevalence of metabolic syndrome (MetS) in Japan, a super-aged society, is increasing and poses a major public health issue. Several studies have reported sex differences in the association between age and MetS prevalence. This study aimed to examine the association between age and the prevalence of MetS based on multiple screening criteria and MetS components by sex. METHODS: We used 6 years of individual-level longitudinal follow-up data (June 2012 to November 2018; checkup year: 2012-2017) of middle-aged and older adults aged 40-75 years in Japan (N = 161,735). The Joint Interim Statement criteria, International Diabetes Federation criteria, and another set of criteria excluding central obesity were used as the screening criteria for MetS. The prevalence of MetS and MetS components was cross-sectionally analyzed according to sex and age. A longitudinal association analysis of age, MetS, and MetS components by sex was performed using a multilevel logistic model, adjusted for lifestyle- and regional-related factors. RESULTS: Sex differences were observed in the prevalence and association of MetS and MetS components. In all age groups, the prevalence of central obesity was higher among women, and the prevalence of high blood pressure and fasting glucose was higher among men (P < 0.001). The prevalence of high triglyceride and low high-density lipoprotein cholesterol was higher among women aged > 60 years (P < 0.05). Based on the criteria of the Joint Interim Statement and International Diabetes Federation, the prevalence of MetS was higher among women than in men aged > 55 years (P < 0.001). Men had a higher prevalence of MetS without central obesity than women in all age groups (P < 0.001). The odds ratio for MetS and MetS components with aging was greater among women than in men. CONCLUSIONS: Medical management should be based on the prevalence of MetS and its components according to sex and age. In particular, the high prevalence of MetS without central obesity in middle-aged and older Japanese men suggests that the adoption of the Joint Interim Statement criteria, which do not precondition central obesity, should be considered.

Associations of Lifestyle-Related Factors With Body Mass Index and Blood Pressure in the Middle-Aged and Older Population-Based Cohort in Japan: A Longitudinal Study.

This study aims to analyze associations between lifestyle-related factors and body mass index (BMI) and blood pressure (BP) in middle-aged and older people in Japan. An association analysis using a multilevel model with demographic and lifestyle-related factors as variables and with BMI, systolic blood pressure (SBP), and diastolic blood pressure (DBP) as outcomes was conducted. Among the modifiable lifestyle factors, we found a significant dose-response association for BMI and slower eating (fast: reference; normal: -0.123 kg/m2 and slow: -0.256 kg/m2). Consuming >60 g/d ethanol was significantly associated, before and after adjustment for BMI, with an increase in SBP of 3.109 and 2.893 mm Hg, respectively. These findings suggested that health guidance should focus on factors such as the eating rate and drinking habits.

Examining proximity to death and health care expenditure by disease: a Bayesian-based descriptive statistical analysis from the National Health Insurance database in Japan.

BACKGROUND: Japan is one of the Organization for Economic Co-operation and Development (OECD) countries where population aging and increasing health care expenditures (HCE) are urgent issues. Recent studies have identified factors other than age, such as proximity to death and morbidity, as contributing factors to the increase in medical costs. It is important to assess HCE by disease and analyze their factors to estimate and improve future HCE. METHODS: We extracted individual records spanning approximately 2 years prior to the death of persons aged 65 to 95 years from the National Health Insurance data in Japan, and used a Bayesian approach to decompose monthly HCE into five disease groups (circulatory, chronic kidney disease, neoplasms, respiratory, and others). The relationship between the proximity to death and the average HCE in each disease group was stratified by sex and age and analyzed using a descriptive statistical method similar to the two-part model. RESULTS: The average HCE increased rapidly as death approached in most disease groups, but the increase-pattern differed greatly among disease groups, sex, and age groups. The effect of proximity to death on average HCE was small for chronic diseases, but large for lethal diseases. When stratified by age and sex, younger and male decedents tended to have higher average HCE, but the extent of this varied by disease group. The two-year cumulative average HCE for neoplasms in the 65-75 years age group was about six times larger than those in the 85-95 years age group. CONCLUSIONS: In Japan, it was suggested that disease, proximity to death, age, and sex may contribute to HCE. However, these factors interact in a complex manner, and it is important to analyze HCE by disease. In addition, preventing or delaying the severity of diseases with high medical burdens in younger people may be effective in reducing future terminal care costs. These findings have important implications for future projections and improvements of HCE.

Home-care robots - Attitudes and perceptions among older people, carers and care professionals in Ireland: A questionnaire study.

Many countries face major challenges to ensure that their health and social care systems are ready for the growing numbers of older people (OP). As a way of realising ageing in place, assistive technologies such as home-care robots are expected to play a greater role in the future. In Asia and Europe, robots are gradually being adopted as a public policy solution to the workforce shortage. Yet, there is still a strongly held belief that such technologies should not be part of human and personal care services such as OP's care. However, there has been little research into attitudes and perceptions of potential users regarding home-care robots which can provide companionship and support with activities of daily living. To explore these in more detail, a questionnaire study was carried out in Finland, Ireland and Japan. This study reports findings from the Irish cohort (114 older people [OP], 8 family carers and 56 Health and Social Care Professionals [HSCPs]). Seventy per cent of the total respondents (N = 178) reported being open to the use of home-care robots, and only one quarter had a negative image of robots. People with care responsibilities in their private capacity expressed more interest in, and readiness to use, home-care robots, while stressing the importance of 'privacy protection' and 'guaranteed access to human care'. Both OP and HSCPs identified observation and recording of OP's mental and physical condition as desirable functions of such robots, whereas practical functions such as fall prevention and mobility support were also deemed desirable by HSCPs. There is generally positive interest in home-care robots among Irish respondents. Findings strongly suggest that the interest is generated partly by great need among people who deliver care. Should such robots be developed, then careful consideration must be given to user-centred design, ethical aspects and national care policy.

COVID-19 and Long-Term Care Policy for Older People in Japan.

Japan's initial response to COVID-19 was similar to that of the US. However, the number of deaths in Japan has remained very low. Japan also stands out for the relatively low incidence of viral transmission in Long-Term Care Facilities (LTCFs) compared to both European countries and the United States. We argue that Japan's institutional decision to lockdown Long-Term Care facilities as early as mid-February - weeks earlier than most European countries and the US - contributed to lowering the number of deaths in LTCFs. We highlight a few lessons from the Japanese experience: (i) the presence of hierarchically organized government agencies whose sole missions are elderly care; (ii) the presence of effective communication channels between LTCFs and the regulatory authorities; and (iii) the well-established routine protocols of prevention and control in LTCFs.

Testing the Construct Validity and Responsiveness of the Single-Item Presenteeism Question.

OBJECTIVE: We tested the construct validity and responsiveness of a single-item instrument for measuring absolute presenteeism-the single-item presenteeism question (SPQ). METHODS: Two self-report questionnaire surveys were conducted among employees of 24 small- or medium-sized companies (N = 1021) concerning the recognized predictors of presenteeism-absenteeism, subjective health risks, work engagement, and workplace social capital. Responsiveness was measured by determining whether changes in the presence of predictors between the surveys were accompanied by commensurate changes in SPQ presenteeism. RESULTS: SPQ presenteeism exhibited significant associations with the predictors, denoting adequate construct validity. Regarding responsiveness, unfavorable changes in most predictors were associated with increased SPQ presenteeism, as expected. CONCLUSIONS: We confirmed the construct validity and responsiveness of the SPQ-an instrument that can be employed to promote workplace health and productivity management.

Exploring perceptions toward home-care robots for older people in Finland, Ireland, and Japan: A comparative questionnaire study.

PURPOSE: To clarify potential users' perceptions toward the development and social implementation of home-care robots in Japan, Ireland, and Finland. METHODS: Unsigned, self-administered questionnaires were distributed to adults aged 65 or older, family caregivers, and home-care/health and social care professionals (HSCPs). A total of 1004 responses were collected. RESULTS: In Japan, many people were already familiar with robots in their daily lives. The most notable finding about their perspectives on home-care robots was related to safety. Moreover, 93.7 % of the Japanese respondents said, "If the user cannot decide whether to use a home-care robot, family members who know the user well should decide," followed by 76.4 % in Ireland and 83.1 % in Finland (p < .001). In Ireland, 81.8 % of the respondents said, "I want to help other people and society by participating in the research and development of home-care robots" (Japan: 69.9 %; Finland: 67.5 %) (p = .006). In Finland, many people had a negative impression of robots compared to the other two countries. Finland had the highest percentage (75.4 %) of respondents who said, "Health care professionals should be allowed to use secondary information collected by a home-care robot" (Japan and Ireland: 64 %) (p = .024). Moreover, Ireland and Finland emphasized the need to guarantee the entitlement to receive human care. CONCLUSIONS: Devising optimal strategies for the development and social implementation of home-care robots by incorporating various perspectives while valuing human dignity will require examination of each country's characteristics with respect to history, culture, policies, and values related to robots.

Maintaining Physical Activity Level Through Team-Based Walking With a Mobile Health Intervention: Cross-Sectional Observational Study.

BACKGROUND: The health conditions of Japanese salespersons may be adversely affected by their lifestyle. Face-to-face or on-site health interventions are not convenient for salespersons because of their tendency for out-of-office sales. Previous studies showed that mobile health (mHealth) interventions (compared to usual practice) have great potential to promote physical activity. For Japanese salespersons, mHealth can offer additional convenience to change their physical activity habits because they can access the mHealth contents anytime and anywhere. However, the specific elements that are most important to maintain physical activity levels using an mHealth approach remain unclear. OBJECTIVE: We aimed to identify elements that account for both a high average physical activity level and can help to prevent a decrease in physical activity during a 9-week intervention period. METHODS: Salespersons were recruited from 11 Japanese companies. A team-based walking intervention was held from October to December 2018 (for a total of 9 weeks), during which the walking step data were recorded by smartphone apps. Average walking steps of each participant during the intervention and the difference in walking steps between the initial and the final week were respectively used as dependent variables. The effects of team characteristics (ie, frequency of communication with team members and team size) and behavioral characteristics (ie, number of days with recorded steps on the apps) on the average walking steps, and the difference in walking steps between the initial and the final week were estimated using multiple and multilevel regression analyses. RESULTS: Of the 416 participants, walking step data of 203 participants who completed postintervention assessments were included in the analyses. Multiple regression analysis of the average walking steps showed that the number of days with recorded steps was positively correlated with the log-transformed average walking steps (ß=.01, P<.001). Multilevel analysis of the average walking steps considering the company level estimated that the intraclass correlation coefficient was 37%. This means that belonging to the same company largely affected an individual's average walking steps. Multiple regression analysis of the difference in walking steps showed that communication with team members once or twice a week correlated with preventing a decrease in walking steps from the initial to the final week (ß=1539.4, P=.03), and being on a larger team correlated with a decrease in walking steps from the initial to the final week (ß=-328.4, P=.01). CONCLUSIONS: This study showed that the elements accounting for high average walking steps and those preventing the decrease in walking steps from the initial to the final week differed. Behavioral characteristics correlated positively with average walking steps. Team characteristics (ie, regular communication and a smaller team size) significantly correlated with preventing a decrease in walking steps.

Metabolic syndrome: Association between prevalence and risk at worksites.

This study, conducted at major Japanese companies, aimed to determine if asymptomatic workers in workplaces with a high prevalence of metabolic syndrome have a greater risk of developing metabolic syndrome. Data were obtained from the health records of 298,145 people, from 2011 to 2015. We collected data on the participants' age, sex, physical examinations, laboratory tests, and lifestyle behaviors. To test whether the risk of metabolic syndrome in asymptomatic workers differed between groups with a higher and lower prevalence in 2011, Cox proportional hazards regression model was performed, with the covariates being controlled for. The analysis showed that the risk of metabolic syndrome among asymptomatic workers in the high-prevalence group was about 1.1-fold elevated compared to those within the low-prevalence group. As a follow-up to these results, interventions aimed at asymptomatic workers should be provided in workplaces with a high prevalence of metabolic syndrome.

Board certification and urban-rural migration of physicians in Japan.

BACKGROUND: The board certification system serves as a quality assurance system for physicians, and its design and operation are important health policy issues. In Japan, board certification was established and operated independently by academic societies and has not been directly linked to reimbursement systems. The phenomenon of younger physicians seeking specialist careers has raised concerns about acceleration of the tendency of fewer physicians working in rural areas and the maldistribution of physicians. Little is known about the associations between physicians' geographical migration patterns and board certification status changes or between the continuation of urban/rural practice and the maintenance of board certification. This study aimed to identify these associations and to discuss their policy implications. METHODS: We analyzed 2012 and 2014 data from the Survey of Physicians, Dentists, and Pharmacists, a national census survey. To analyze geographical migration patterns, transitions in practice location (rural, intermediate, and urban) were analyzed by board certification status change (new, lost, consistently certified, and consistently uncertified). Logistic regression analysis was conducted to assess whether the odds of migrating to more urban/rural municipalities were associated with board certification status changes, adjusting for covariates, and whether practicing in a rural area was associated with maintaining board certification. RESULTS: Among 18,726 newly board-certified physicians, 94.9% (13,435/14,150) of those working in urban areas before certification remained in urban areas, whereas 64.6% (393/608) of those working in rural areas stayed in rural areas. Those who were newly certified had higher odds of moving to more urban areas, adjusting for covariates. Those who stayed in rural areas showed lower odds of maintaining board certification, adjusting for covariates. CONCLUSIONS: Newly board-certified physicians are more likely to migrate to other types of areas, particularly more urban areas, than other physicians. Allocating more training quotas to rural areas could be one option for leveling the distribution of specialists. It also appeared that those practicing in rural areas have difficulty maintaining their certification, so the need to establish a support system for already-certified physicians in rural areas should be emphasized.

The distance and chance of lifetime geographical movement of physicians in Japan: an analysis using the age-period-cohort model.

BACKGROUND: The uneven geographical distribution of physicians in Japan is a result of those physicians electing to work in certain locations. In order to understand this phenomenon, it is necessary to analyze the geographic movement of physicians across the Japanese landscape. METHODS: We obtained individual data on physicians from 1978 to 2012 detailing their attributes, work institutions, and locations. The data are from Japanese governmental sources (the Survey of Physicians, Dentists, and Pharmacists). The total sample size was 122 150 physicians, with 77.5% being male and 22.5% female. After obtaining the data, we calculated the geographical distance of each physician's movement by using geographic information systems software (GIS; ArcGIS, ESRI, Inc., CA, USA). Geographical distance was then converted into time distance. We compared the resulting median values through nonparametric testing and then conducted a multivariate analysis. Our next step involved the use of an age-period-cohort (APC) model to measure the degree of impact three points of data, experience (experience years), the historical and environmental context of the data (survey year), and physician cohort (registration year) had on the movement of each physician. RESULTS: The ratio of female physicians who selected an urban area as their first working location was higher than that of male physicians. However, the selection of an urban area was becoming more popular as a first working location for both males and females as the year of data increased. The overall distance of geographical movement for female physicians was less than it was for male physicians. Physicians moved the greatest distance between their second and fourth years following license acquisition, at which point the time distance became shorter. The median time distance was 46 min in 2000 and 22 min in 2008. The physicians in our study did not move far from their first working location, and the overall distance of movement lessened in the more recent years of study. The median distance of movement after 20 years was 25.9 km for male physicians, and 19.1 km for female physicians. The results of the APC model indicated that the effects of experience years (age) gradually declined, that the survey year (period) effects increased, and that the registration year (cohort) effects increased initially before leveling off. CONCLUSIONS: The trends following the introduction of the new mandatory training system in 2004 may imply that the concentration of physicians in Japan's urban areas is expected to increase. After 2000, the effect of that period on physicians explains their geographical movements more so than the factor of their age.

Estimation and Evaluation of Future Demand and Supply of Healthcare Services Based on a Patient Access Area Model.

Accessibility to healthcare service providers, the quantity, and the quality of them are important for national health. In this study, we focused on geographic accessibility to estimate and evaluate future demand and supply of healthcare services. We constructed a simulation model called the patient access area model (PAAM), which simulates patients' access time to healthcare service institutions using a geographic information system (GIS). Using this model, to evaluate the balance of future healthcare services demand and supply in small areas, we estimated the number of inpatients every five years in each area and compared it with the number of hospital beds within a one-hour drive from each area. In an experiment with the Tokyo metropolitan area as a target area, when we assumed hospital bed availability to be 80%, it was predicted that over 78,000 inpatients would not receive inpatient care in 2030. However, this number would decrease if we lowered the rate of inpatient care by 10% and the average length of the hospital stay. Using this model, recommendations can be made regarding what action should be undertaken and by when to prevent a dramatic increase in healthcare demand. This method can help plan the geographical resource allocation in healthcare services for healthcare policy.

Internal medicine board certification and career pathways in Japan.

BACKGROUND: Establishing and managing a board certification system is a common concern for many countries. In Japan, the board certification system is under revision. The purpose of this study was to describe present status of internal medicine specialist board certification, to identify factors associated with maintenance of board certification and to investigate changes in area of practice when physicians move from hospital to clinic practice. METHODS: We analyzed 2010 and 2012 data from the Survey of Physicians, Dentists and Pharmacists. We conducted logistic regression analysis to identify factors associated with the maintenance of board certification between 2010 and 2012. We also analyzed data on career transition from hospitals to clinics for hospital physicians with board certification. RESULTS: It was common for physicians seeking board certification to do so in their early career. The odds of maintaining board certification were lower in women and those working in locations other than academic hospitals, and higher in physicians with subspecialty practice areas. Among hospital physicians with board certification who moved to clinics between 2010 and 2012, 95.8% remained in internal medicine or its subspecialty areas and 87.7% maintained board certification but changed their practice from a subspecialty area to more general internal medicine. CONCLUSION: Revisions of the internal medicine board certification system must consider different physician career pathways including mid-career moves while maintaining certification quality. This will help to secure an adequate number and distribution of specialists. To meet the increasing demand for generalist physicians, it is important to design programs to train specialists in general practice.

The effect of concentrating obstetrics services in fewer hospitals on patient access: a simulation.

BACKGROUND: In Japan, the number of obstetrics facilities has steadily decreased and the selection and concentration of obstetrics facilities is progressing rapidly. Obstetrics services should be concentrated in fewer hospitals to improve quality of care and reduce the workload of obstetricians. However, the impact of this intensification of services on access to obstetrics hospitals is not known. We undertook a simulation to examine how the intensification of obstetrics services would affect access to hospitals based on a variety of scenarios, and the implications for health policy. METHODS: The female population aged between 15 and 49 living within a 30-min drive of an obstetrics hospital was calculated using a Geographic Information System for three possible intensification scenarios: Scenario 1 retained facilities with a higher volume of deliveries without considering the geographic boundaries of Medical Service Areas (MSAs, zones of healthcare administration and management); Scenario 2 prioritized retaining at least one hospital in each MSA and then retained higher delivery volume institutions, while Scenario 3 retained facilities to maximize population coverage using location-allocation modeling. We also assessed the impact of concentrating services in academic hospitals and specialist perinatal medical centers (PMCs) alone. RESULTS: In 2011, 95.0% of women aged 15-49 years lived within a 30-min drive of one of 1075 obstetrics hospitals. This would fall to 82.7% if obstetrics services were intensified into academic hospitals and general and regional PMCs. If 55.0% of institutions provided obstetrics services, the coverage would be 87.6% in Scenario 1, whereas intensification based on access would achieve over 90.5% coverage in Scenario 2 and 93.9% in Scenario 3. CONCLUSIONS: Intensification of obstetrics facilities impairs access, but a greater caseload and better staffing have the potential advantages of better clinical outcomes and reduced costs. It is essential to consult residents of hospital catchment areas when reorganizing clinical services; a simulation is a useful means of informing these important discussions.

Career pathways of board-certified surgeons in Japan.

PURPOSE: To investigate the career pathways of board-certified surgeons' and the factors associated with them maintaining their certification in Japan. METHODS: We analyzed data from the surveys of physicians, dentists and pharmacists. A multivariate logistic regression model was used to investigate whether factors such as gender, year of registration, place of work, and subspecialty board certification were associated with maintaining board certification. RESULTS: Most Japanese surgeons attain board certification within 5-10 years of initial medical registration. After adjusting for possible confounding factors, the odds of maintaining board certification were significantly lower for women, those who were beyond 20 years post-registration, those who worked in hospitals other than academic hospitals or clinics, and those who had board certification in surgery only. Of the total board-certified surgeons analyzed, 93.2 % continued to work in hospitals and 2.8 % moved to clinics within 2 years. Of those who moved from hospitals to clinics, half continued to practice surgery, while nearly 40 % changed their specialty to internal medicine. CONCLUSION: It is necessary to establish a special training system for mature surgeons who move from surgery to general practice later in their careers. As the number of female surgeon increases, a support system is also required to secure the future supply of surgeons.

Selection and concentration of obstetric facilities in Japan: Longitudinal study based on national census data.

AIM: A shortage of obstetricians with increased workload is a social problem in Japan. In response, the government and professional bodies have accelerated the 'selection and concentration' of obstetric facilities. The aim of this study was to evaluate the recent trend of selection and concentration. METHODS: We used data on the number of deliveries and of obstetricians in each hospital and clinic in Japan, according to the Static Survey of Medical Institutions in 2005, 2008 and 2011. To evaluate the inter-facility equality of distribution of the number of deliveries, number of obstetricians and number of deliveries per obstetrician, Gini coefficients were calculated. RESULTS: The number of obstetric hospitals decreased by 20% and the number of deliveries per hospital increased by 26% between 2005 and 2011. Hospital obstetricians increased by 16% and the average number of obstetricians per hospital increased by 19% between 2008 and 2011. Gini coefficient of deliveries has significantly decreased. In contrast, Gini coefficient of deliveries per obstetrician has significantly increased. The degree of increase in obstetricians and of decrease in deliveries per obstetrician was largest at the hospitals with the highest proportion of cesarean sections. The proportion of obstetric hospitals with the optimal volume of deliveries and obstetricians, as defined by Japan Society of Obstetrics and Gynecology, was 4% in 2008, and it had doubled to 8.1% 3 years later. CONCLUSION: The selection and concentration of obstetric facilities is progressing rapidly and effectively in Japan.

Using geographic information systems to simulate patient access areas.

We constructed a simulation model with a geographic information system (GIS) to predict the future shortage of beds in the Tokyo Metropolitan Area. With a grid square method, we calculated patient numbers for every 500 square meters of the Tokyo Metropolitan Area until 2040 and estimated whether those in need could be admitted to hospitals within an hour's drive from their homes. The simulation demonstrates that after 2025 many patients may not be able to find hospitals within this time framework. The situation will be especially serious in the center of Tokyo and along the railway lines, where many senior citizens reside. We can now apply this innovative GIS method in many fields and especially for the precise estimation of future demands for and supply of medical assistance.

Socio-demographic and lifestyle factors for child's physical growth and adiposity rebound of Japanese children: a longitudinal study of the 21st century longitudinal survey in newborns.

BACKGROUND: It is unknown whether childhood physical development in Asian populations differs from western populations, since no longitudinal analysis has been performed in Asian countries yet. Utilizing the 21st Century Longitudinal Survey in Newborns, we studied the timing of adiposity rebound (AR) among Japanese children and determined whether AR occurs earlier in obese children compared to nonobese children. Furthermore, we identified important demographic, social, and lifestyle factors that affect their physical development. METHODS: We used data from the annual surveillance of Japanese children born in 2001, with 45,392 eligible subjects. We applied survival analysis to evaluate the AR and a trajectory method for the BMI transition across 5 ½ years. Time-dependent and time-independent factors affecting BMI changes were investigated using longitudinal analysis. Accounting for the known difference in prevalence between Japanese and Western children, we adopted a 95th percentile of BMI as criterion for obesity. RESULTS: Mean BMI at birth and at ages 1 ½, 2 ½, 3 ½, 4 ½, and 5 ½ years for all subjects were 12.6, 16.3, 16.1, 15.8, 15.5, and 15.4, respectively, showing a progressive reduction after 1 ½ years. However, among obese children at 5 ½ years, 39.6% had experienced AR as early as at age 4 ½ years. Controlling for sex, Cox's proportional hazards model showed that obese children had a 48.5% higher hazard to experience AR than nonobese children. The difference in BMI transition between obese and non-obese children was also captured by a trajectory method. In longitudinal analysis, BMI was lower for children who had a longer gestational period whereas children who received parental care from non-family members gained higher BMI values. CONCLUSIONS: With the 95th percentile cutoff for children obesity, obese Japanese children developed AR earlier than nonobese Japanese children, similar to those in Western countries reported in the literature. Primary caretakers and length of gestational period were the most important socio-demographic factors affecting physical development.

Physician-scientists in Japan: attrition, retention, and implications for the future.

PURPOSE: To investigate career trends for physician-scientists in Japan. METHOD: The authors analyzed 1996-2008 biennial census survey data from Japan's national physician registry to examine trends over time in the numbers and proportion of physician-scientists by sex and years since registration. They also analyzed the transition of registered physicians into and out of the physician-scientist field across two sets of two consecutive surveys (1996-1998 and 2006-2008). RESULTS: The number of physician-scientists between 1996 and 2008 was stable, with a low of 4,893 and a high of 5,325. The number of younger physician-scientists (those registered 0-4 years at the time of the surveys) declined sharply, however, from 828 in 1996 to 253 in 2008. The number of female physician-scientists increased from 528 in 1996 to 746 in 2008. Across the two survey periods, about 30% of physician-scientists left the career path, but this attrition was offset by about the same number of new individuals entering the field. CONCLUSIONS: Although the total number of physician-scientists was relatively unchanged during the period studied, it is essential that educators and policy makers develop approaches to address underlying demographic changes to ensure an adequate age- and gender-balanced supply of physician-scientists in the future.