Greater Tokyo Metropolitan Area Research Articles

Impact of the COVID-19 pandemic on surgical volume and outcomes in spine surgery: a multicentre retrospective study in Tokyo

ObjectivesTo investigate the effect of the COVID-19 pandemic on surgical volume and outcomes in spine surgery.DesignA retrospective cohort study using prospectively collected data.Setting and participantsA total of 9935 patients who...

Effect of Antimicrobial Prophylaxis Duration on Health Care–Associated Infections After Clean Orthopedic Surgery

Postoperative health care-associated infections are associated with a greater deterioration in patients' general health status and social and economic burden, with at least 1 occurring in approximately 4% of acute care hospital patients. Antimicrobial prophylaxis prevents surgical site infections in various orthopedic procedures; however, its relationship with health care-associated infections remains unknown. To examine whether a shorter antimicrobial prophylaxis duration of less than 24 hours after surgery is not inferior to a longer duration in preventing health care-associated infections after clean orthopedic surgery. This open-label, multicenter, cluster randomized, noninferiority clinical trial was conducted in 5 tertiary referral hospitals in greater Tokyo metropolitan area, Japan, from May to December 2018. Adult patients undergoing clean orthopedic surgery were recruited until the planned number of participants was achieved (500 participants per group). Statistical analysis was conducted from July to December 2019. Antimicrobial prophylaxis was discontinued within 24 hours after surgery in group 24 and 24 to 48 hours after surgery in group 48. Group allocation was switched every 2 or 4 months according to the facility-based cluster rule. Study-group assignments were masked from participants. The primary outcome was the incidence of health care-associated infections requiring antibiotic therapies within 30 days after surgery. The noninferiority margin was 4%. Of the 1211 participants who underwent cluster allocation, 633 participants were in group 24 (median [IQR] age, 73 [61-80] years; 250 men [39.5%] and 383 women [60.5%]), 578 participants were in group 48 (median [IQR] age, 74 [62-81] years; 204 men [35.3%] and 374 women [64.7%]), and all were eligible for the intention-to-treat analyses. Health care-associated infections occurred in 29 patients (4.6%) in group 24 and 38 patients (6.6%) in group 48. Intention-to-treat analyses showed a risk difference of -1.99 percentage points (95% CI, -5.05 to 1.06 percentage points; P < .001 for noninferiority) between groups, indicating noninferiority. Results of adjusted intention-to-treat, per-protocol, and per designated procedure population analyses supported this result, without a risk of antibiotic resistance and prolonged hospitalization. This cluster randomized trial found noninferiority of a shorter antimicrobial prophylaxis duration in preventing health care-associated infections without an increase in antibiotic resistance risk. These findings lend support to the global movement against antimicrobial resistance and provide additional information on adequate antimicrobial prophylaxis for clean orthopedic surgery. Identifier: UMIN000030929.

Retrieval of Aerosol Optical Thickness with Custom Aerosol Model Using SKYNET Data over the Chiba Area

The retrieval of the aerosol optical thickness (AOT) from remotely-sensed data relies on the adopted aerosol model. However, the method of this technique has been rather limited because of the high variability of the surface albedo, in addition to the spatial variability in the aerosol properties over the land surfaces. To overcome unsolved problems, we proposed a method for the visibility-derived AOT estimation from SKYNET-based measurement and daytime satellite images with a custom aerosol model over the Chiba area (35.62° N, 140.10° E), which is located in the greater Tokyo metropolitan area in Japan. Different from conventionally-used aerosol models for the boundary layer, we created a custom aerosol model by using sky-radiometer observation data of aerosol volume size distribution and refractive indices, coupled with spectral response functions (SPFs) of satellite visible bands to alleviate the wide range of path-scattered radiance. We utilized the radiative transfer code 6S to implement the radiative transfer calculation based on the created custom aerosol model. The concurrent data from ground-based measurement are used in the radiative analysis, namely the temporal variation of AOT from SKYNET. The radiative estimation conducted under clear-sky conditions with minimum aerosol loading is used for the determination of the surface albedo, so that the 6S simulation yields a well-defined relation between total radiance and surface albedo. We made look-up tables (LUTs) pixel-by-pixel over the Chiba area for the custom aerosol model to retrieve the satellite AOT distribution based on the surface albedo. Therefore, such a reference of surface albedo generated from clear-sky conditions, in turn, can be employed to retrieve the spatial distribution of AOT on both clear and relatively turbid days. The value for the AOTs retrieved using the custom aerosol model is found to be stable than conventionally-used typical aerosol models, indicating that our method yields substantially better performance.

Continuous multi-component MAX-DOAS observations for the planetary boundary layer ozone variation analysis at Chiba and Tsukuba, Japan, from 2013 to 2019

Ground-based remote sensing using multi-axis differential optical absorption spectroscopy (MAX-DOAS) was used to conduct continuous simultaneous observations of ozone (O3), nitrogen dioxide (NO2), and formaldehyde (HCHO) concentrations at Chiba (35.63° N, 140.10° E, 21 m a.s.l.) and Tsukuba (36.06° N, 140.13° E, 35 m a.s.l.), Japan, for 7 years from 2013 to 2019. These are urban and suburban sites, respectively, in the greater Tokyo metropolitan area. NO2 and HCHO are considered to be proxies for nitrogen oxides (NOx) and volatile organic compounds (VOCs), respectively, both of which are major precursors of tropospheric O3. The mean concentrations below an altitude of 1 km were analyzed as planetary boundary layer (PBL) concentrations. For a more spatially representative analysis around the urban area of Chiba, four MAX-DOAS instruments directed at four different azimuth directions (north, east, west, and south) were operated simultaneously and their data were unified. During the 7-year period, the satellite observations indicated an abrupt decrease in the tropospheric NO2 concentration over East Asia, including China. This suggested that the transboundary transport of O3 originating from the Asian continent was likely suppressed or almost unchanged during the period. Over this time period, the MAX-DOAS observations revealed the presence of almost-constant annual variations in the PBL O3 concentration, whereas reductions in NO2 and HCHO concentrations occurred at rates of approximately 6–10%/year at Chiba. These changes provided clear observational evidence that a decreasing NOx concentration significantly reduced the amount of O3 quenched through NO titration under VOC-limited conditions in the urban area. Under the dominant VOC-limited conditions, the MAX-DOAS-derived concentration ratio of HCHO/NO2 was found to be below unity in all months. Thus, the multi-component observations from MAX-DOAS provided a unique data set of O3, NO2, and HCHO concentrations for analyzing PBL O3 variations.

The Political Orientation of Japanese Online Right-wingers

Since the early 2000s, Japan has witnessed the growing salience of so-called netto uyoku (online right-wingers). This group is characterized by strong anti-China and anti-Korea sentiments, nationalistic political views, and online political engagement. While online radical right movements in Europe are often regarded as support bases for radical right candidates or parties, few studies have investigated whether this assumption applies to Japanese online right-wingers. The present study sought to shed light on this issue by conducting a large-scale web survey with 77,084 respondents living in the greater Tokyo metropolitan area. Respondents were registered monitors for a research company. The large sample size enabled multivariate analyses to clarify the characteristics of online right-wingers in comparison to other respondents. The results indicated that 1.5 percent of the respondents (1,167) could be classified as online right-wingers and, in contrast with the political discontent hypothesis, most online right-wingers had a high degree of external political efficacy and lower levels of populist attitudes relative to other respondents. This suggests that online right-wingers trusted and remained satisfied with the current political conditions. Furthermore, they were more likely to vote, especially for established conservative parties, suggesting an affinity among online right-wingers for traditional conservative parties and candidates. These findings indicate that, unlike in Europe, Japanese online right-wingers are not a support base for radical right candidates and parties. In Japan, which is under a right-leaning government, online right-wingers have not become a driving force for emergent radical right parties.

Universal school lunch programme closes a socioeconomic gap in fruit and vegetable intakes among school children in Japan

BackgroundUniversal school lunch programmes are expected to cover all children equally, compared with selective programmes that may stigmatize socially vulnerable children. However, the effectiveness of universal programmes in closing dietary disparity has not been empirically proven. We evaluated whether Japan’s universal school lunch programmes contribute to a reduction in the socioeconomic status (SES)-related gradient in fruit and vegetable intakes.MethodsWe analyzed data for 719 school children aged 6–12 years in a population-based survey conducted in the greater Tokyo metropolitan area. We measured dietary intakes using a validated self-administered brief diet history questionnaire for young children (BDHQ-10 y). We assessed parental education, annual household income and maternal employment status as SES indicators of children. We used multiple regression to estimate mean fruit and vegetable intakes by parental education and household income, and the contribution of school lunch to reducing the SES-related gradient in fruit and vegetable intakes.ResultsCompared with children with high maternal education (>15 years), those with low maternal education (<13 years) had less vegetable intake by 22.3 g/1000 kcal (95% confidence interval = 12.5, 32.2) and less fruit intake by 7.5 g/1000 kcal (95% confidence interval = −2.4, 17.3). However, fruit and vegetable intakes from school lunch did not vary by SES, indicating that school lunch intake alleviated the SES-related gradient of total vegetable intake by 9.9% and that of fruit intake by 3.4%.ConclusionsUniversal school lunch programmes can partially contribute to a reduction in the SES-related gradient in dietary intakes.

Time cost of child rearing and its effect on women's uptake of free health checkups in Japan

Women of child-rearing age have the lowest uptake rates for health checkups in several developed countries. The time cost incurred by conflicting child-rearing roles may contribute to this gap in access to health checkups. We estimated the time cost of child rearing empirically, and analyzed its potential impact on uptake of free health checkups based on a sample of 1606 women with a spouse/partner from the dataset of a population-based survey conducted in the greater Tokyo metropolitan area in 2010. We used a selection model to estimate the counterfactual wage of non-working mothers, and estimated the number of children using a simultaneous equation model to account for the endogeneity between job participation and child rearing. The time cost of child rearing was obtained based on the estimated effects of women's wages and number of children on job participation. We estimated the time cost to mothers of rearing a child aged 0–3 years as 16.9 USD per hour, and the cost for a child aged 4–5 years as 15.0 USD per hour. Based on this estimation, the predicted uptake rate of women who did not have a child was 61.7%, while the predicted uptake rates for women with a child aged 0–3 and 4–5 were 54.2% and 58.6%, respectively. These results suggest that, although Japanese central/local governments provide free health checkup services, this policy does not fully compensate for the time cost of child rearing. It is strongly recommended that policies should be developed to address the time cost of child rearing, with the aim of closing the gender gap and securing universal access to preventive healthcare services in Japan.

Estimation of the Health Status of People in the Vicinity of Pharmacies Using Pharmacy Big Data

The purpose of this study was to propose a method for visualizing the patterns of the geographical propagation of influenza infection, and to elaborate parameters for the characterization of these patterns. First, a motion picture was prepared for the quotidian propagation of influenza infection in the Greater Tokyo Metropolitan area, which is considered a typical epidemic area for the 2012/2013 flu season. Second, hebdomadal recordings of patients with influenza infection in the 47 prefectures of Japan were grouped into 3 categories (1-peak, 2-peak, or multi-peak). The prefectures were arranged according to the weeks with the maximum number of patients, to examine variations in the temporal infection order of the districts among the flu seasons. These characteristics were analyzed using Cramer's coefficient of association and Spearman's rank correlation coefficient. Finally, the propagation of influenza infection was compared between urban and remote areas: the Greater Tokyo Metropolitan area and Tochigi prefecture. Regarding influenza virus infection, differences in population density, public transportation systems, and lifestyles between the urban and rural areas were found to lead to distinct endemic patterns of infection. Emphasis was placed on the so-called big data hubris.

Japanese study on stratification, health, income, and neighborhood: study protocol and profiles of participants.

BackgroundThe Japanese Study on Stratification, Health, Income, and Neighborhood (J-SHINE) aims to clarify the complex associations between social factors and health from an interdisciplinary perspective and to provide a database for use in various health policy evaluations.MethodsJ-SHINE is an ongoing longitudinal panel study of households of adults aged 25–50 years. The wave 1 survey was carried out in 2010 among adults randomly selected from the resident registry of four urban and suburban municipalities in the greater Tokyo metropolitan area, Japan. In 2011, surveys for the participants’ spouse/partner and child were additionally conducted. The wave 2 survey was conducted in 2012 for the wave 1 participants and will be followed by the wave 2 survey for spouse/partner and child in 2013.ResultsWave 1 sample sizes were 4357 for wave 1 participants (valid response rate: 31.3%; cooperation rate: 51.8%), 1873 for spouse/partner (response rate: 61.9%), and 1520 for child (response rate: 67.7%). Wave 2 captured 69.0% of wave 1 participants. Information gathered covered socio-demographics, household economy, self-reported health conditions and healthcare utilization, stress and psychological values, and developmental history. A subpopulation underwent physiological (n = 2468) and biomarker (n = 1205) measurements.ConclusionsLongitudinal survey data, including repeated measures of social factors evaluated based on theories and techniques of various disciplines, like J-SHINE, should contribute toward opening a web of causality for society and health, which may have important policy implications for recent global health promotion strategies such as the World Health Organization’s Social Determinants of Health approach and the second round of Japan’s Healthy Japan 21.

Changing demographics in Japan's national parks; towards a targeted marketing strategy for nature-based tourists

Trends from Japan and other post-industrial countries suggest visitor demand for nature-based tourism (NBT) destinations such as national parks, which rocketed in the post-war period, has peaked and is now in decline. This has adverse implications for funding and natural resource management. One suggested counter strategy is targeted marketing based on commercial techniques, but this relies on accurate knowledge of the market to maintain current segments and attract new ones.This paper employs a ‘market leader’ case study approach to investigate visitors to Kamikochi, a gateway to the North Japan Alps whose long conservation pedigree, and proximity to urban areas, ensures it can fulfil both ‘protection’ and ‘promotion’ criteria. The focus was on the Day Hiker (Dh) segment of visitor demand, deemed desirable from a managerial perspective, because they were shown to stay longer, visit more frequently and have a greater interaction with nature. The aims were to identify the composition of Kamikochi’sDh visitor segment, and cross analyse the results to provide practical information for national park managers. Following on from a 2007 survey, 391 usable semi-structured questionnaires were collected between July 10th and September 10th 2009, from participants in guided tours at Kamikochi, a response rate of 31%. Results show the ‘market leader’ segment consisted of pairs or small groups of well-educated, wealthy ‘baby-boomers’ from Kanto; 55% were aged 50 or over, and 59% came from the greater Tokyo metropolitan area. These KantoDhs tended to be repeat visitors (66.0%) who stayed for 2 nights or more (55.1%), thus surpassing the bench mark set by previous research. However, the results provided a snapshot of visitor demand unbalanced not only by urban area, but also gender, age and income; hence further research is needed to explain the dominance of female, elderly and wealthy visitors. One logical explanation is that these segments are already being targeted by travel agencies, as suggested by the 42% who came to Kamikochi as part of a package tour. If so, then it raises the question of why marketing is being outsourced to travel agencies rather than conducted via joint campaigns that incorporate a range of stakeholders.Thus although the need for targeted marketing is clear, some significant barriers to marketing NBT resources exist, including diverse objectives, mixed land ownership and insufficient funding. Transparent goals, combined with ongoing visitor segment monitoring, are thus two vital steps towards a targeted NBT marketing strategy.

Radioactivity concentrations of 131I, 134Cs and 137Cs in river water in the Greater Tokyo Metropolitan area after the Fukushima Daiichi Nuclear Power Plant Accident

Radioactivity concentrations of 131I, 134Cs and 137Cs in river water in the Greater Tokyo Metropolitan area after the Fukushima Daiichi Nuclear Power Plant Accident

Current prevalence of HTLV‐1 in Japan as determined by screening of blood donors

Human T-cell leukemia virus type-1 (HTLV-1), a major source of adult T-cell leukemia and related diseases, is endemic to southwestern Japan. Mother-to-infant transmission via breast milk is an important route of infection, and establishing programs to prevent such transmission requires exact figures on the HTLV-1 prevalence rate and the number of carriers. Therefore, the seroprevalence of HTLV-1 among 1,196,321 Japanese first-time blood donors from 2006 to 2007 was investigated. A total of 3,787 of such donors were confirmed to be positive for anti-HTLV-1 antibody. By applying a fitness curve to the age ranges outside the blood donor age range, the present number of HTLV-1 carriers covering ages from 0 to 99 years was estimated to be at least 1.08 million in Japan; this value was 10% lower than that reported in 1988. The adjusted overall prevalence rates were estimated to be 0.66% and 1.02% in men and women, respectively. The peak in carrier numbers was found among individuals in their 70s, which is a shift from the previous peak observed in the 1988 database among individuals in their 50s. Carriers were distributed not only in the endemic southwestern region of Japan, but throughout the country, particularly in the greater Tokyo metropolitan area. By applying population projections, it was calculated that the carrier number will decrease by half in the next two decades; however, the carrier population will age over that interval, meaning that the age of patients with adult T-cell leukemia will also be higher.

Can I have a second child? dilemmas of mothers of children with pervasive developmental disorder: a qualitative study

BackgroundPervasive developmental disorder (PDD) has an uncertain etiology, no method of treatment, and results in communication deficiencies and other behavioral problems. As the reported recurrence risk is 5%-10% and there are no methods of either prevention or prenatal testing, mothers of PDD children may face unique challenges when contemplating second pregnancies. The purpose of this study was to explore the mothers' lived experiences of second child-related decision-making after the birth of a child with PDD.MethodsThe participants for this study were restricted to mothers living within the greater Tokyo metropolitan area who had given birth to a first child with PDD within the past 18 years. The ten participants were encouraged to describe their experiences of second-child related decision-making after the birth of a child with PDD on the basis of semi-structured interviews. Data analysis was performed by using Interpretive Phenomenological Analysis (IPA), which is concerned with understanding what the participant thinks or believes about the topic under discussion.ResultsWe identified two superordinate themes. The first was balancing hopes and fears, in which hope was the potential joy to be gained by the birth of a new child without PDD and fears were characterized as uncertainty of PDD and perception of recurrence risk, burden on later-born children, and negative effects on a child with PDD.The second superordinate theme was assessing the manageability of the situation, which was affected by factors as diverse as severity of PDD, relationship between mother and father, and social support and acceptance for PDD. Our 10 participants suffered from extreme psychological conflict, and lack of social support and acceptance for PDD created numerous practical difficulties in having second children.ConclusionsOur participants faced various difficulties when considering second pregnancies after the birth of children with PDD in the Japanese society. As lack of social support and acceptance for PDD also played a large role in second child-related decision-making, creating a social environment that more fully accepts those disabled and providing flexible support systems for families of children with PDD are crucial.

2009年台風18号による被害の概要と首都圏鉄道の運行障害

2009年台風18号による被害の概要と首都圏鉄道の運行障害

Individual Sound Exposure Level during Sleep in Relation to Road Traffic Noise in the Greater Tokyo Metropolitan Area

Individual Sound Exposure Level during Sleep in Relation to Road Traffic Noise in the Greater Tokyo Metropolitan Area

Inside one of largest capacity drainage pump stations in the world

The biggest technological task in flood control is how rapidly storm water on a wide flat land can be drained to pumping stations and/or to the sea. A pressurized underground drainage pipeline system is most effective because it provides a wave transmission speed of about 500 m/s and can respond to the water flow from upstream – much better than a typical open canal with the transmission speed of only about 3 m/s. Hideki Kanno of Ebara Corporation takes World Pumps inside the performance of a large capacity flood-control pipeline system established in the greater Tokyo metropolitan area.

A PRELIMINARY INVESTIGATION OF A MODEL ON THE DECISION TO IMPLEMENT TELEWORKING IN THE JAPANESE BUSINESS ORGANIZATIONS

Teleworking, an alternative form of work arrangement, has gained very little significance in the present information era, as otherwise expected, in modem Japan. Existence of many factors would be directly responsible for the slow growth of teleworking in Japan. This paper highlights few significant factors responsible for the decision to accept teleworking as an alternate work arrangement as expressed by the managers of different business organizations in the Greater Tokyo Metropolitan Area (GTMA). These factors include but not limited to: organizational values, advantages of teleworking, performance evaluation, strategically measures and information technology requirements. A logistic regression model was developed to test the significance of these factors against the decision to implement teleworking. Finally, conclusions were also drawn.

A PRELIMINARY INVESTIGATION OF A MODEL ON THE DECISION TO IMPLEMENT TELEWORKING IN THE JAPANESE BUSINESS ORGANIZATIONS

Teleworking, an alternative form of work arrangement, has gained very little significance in the present information era, as otherwise expected, in modem Japan. Existence of many factors would be directly responsible for the slow growth of teleworking in Japan. This paper highlights few significant factors responsible for the decision to accept teleworking as an alternate work arrangement as expressed by the managers of different business organizations in the Greater Tokyo Metropolitan Area (GTMA). These factors include but not limited to: organizational values, advantages of teleworking, performance evaluation, strategically measures and information technology requirements. A logistic regression model was developed to test the significance of these factors against the decision to implement teleworking. Finally, conclusions were also drawn.

Mental Health in Tokyo

Edo, meaning river mouth, the original name of Tokyo, first appeared in written records at the end of the twelfth century. In 1457, during the Muromachi Era, Edo Castle was built. In 1603 Tokugawa Ieyasu was named Shogun and established the Edo shogunate. By about 1616, Edo was one of the greatest cities in the world, with a population of over a million [1,2]. After the Meiji Restoration in 1868, the capital was moved from Kyoto to Edo, which was renamed Tokyo; and the castle became the Imperial Palace, where Meiji Tennou, the emperor, and the imperial families lived. Following the Great Kanto Earthquake in 1923, fires devastated Tokyo; and during Worl War II, from 1943 to 1945, Tokyo suffered extensive damage from heavy bombing by the U.S. Air Force. Both of these disasters ruined much of what had been left of Edo. However, Tokyo has been reconstructed, and is now one of the world's principal cities, a center of political, economic, industrial, and cultural activities. Located almost in the center of the country in the southern part of the Kanto plain, the largest area in a narrow island country, it is the capital of Japan and its largest and busiest city. Tokyo's special metropolitan prefecture (called Tokyo City in English) stretches about 90 kilometers east to west, and some 25 kilometers north to south; it encompasses some 2,150 square kilometers. The greater Tokyo metropolitan area includes not only Tokyo City but also the three adjoining prefectures of Saitama, Kanagawa, and Chiba, covering an area of roughly 1,600 square kilometers. The city has two international airports, a port, and numerous subway lines, and is the center of the country's extensive, nationwide, railway system.