研究者業績

豊川 智之

トヨカワ サトシ  (Satoshi Toyokawa)

基本情報

所属
和洋女子大学 看護学部

J-GLOBAL ID
200901030653467405
researchmap会員ID
5000046523

研究キーワード

 4

論文

 9
  • Hirokazu Tanaka, Atsushi Miyawaki, Satoshi Toyokawa, Yasuki Kobayashi
    Environmental Health and Preventive Medicine 23 2018年12月22日  査読有り
    © 2018 The Author(s). Background: As society is aging, retirement takes on increasing importance for individuals in the later life. This study aimed to describe mortality before and after retirement in the Japanese middle-aged/elderly with special attention to socioeconomic position and social relationships. Methods: We conducted a 10-year follow-up study (the Komo-Ise cohort study) and assessed mortality according to socioeconomic positions (relative poverty and occupation) and social relationships (e.g., marital status, living alone, and social support) in workers and the retired. Relative poverty was defined as a household equivalent income of 12,700 US dollars (1.37 million Japanese Yen) or less in 2000. Stratified analyses were conducted according to sex in two groups of employment status: the workers and the retired. Adjusted hazard ratios (HRs) were calculated using the Cox proportional hazard model. Results: We included 5534 individuals. Of these, 3360 were men (working, 2499; retired, 861) and 2174 were women (working, 1306; retired, 868). We observed 610 deaths (475 in men and 135 in women) during the study period. Relative poverty was a significant risk factor for death (HR 1.52, 95% confidence interval [CI] 1.07-2.14) among retired men but not among working men (HR 1.20, 95% CI 0.79-1.83). Among workers, self-employed men showed a significantly higher hazard of death (HR 1.57, 95% CI 1.09-2.25) than white-collar employees. Retired men who lacked participation in social activities were more likely to die than those who did not (HR 1.44, 95% CI 1.06-1.94). All results, except marital status, indicated non-significant associations in women. Conclusions: Relative poverty and lack of social engagement may be related to high mortality risk in retired men. Further studies are needed to assess the health status among the middle-aged/elderly population around retirement.
  • Hirokazu Tanaka, Satoshi Toyokawa, Nanako Tamiya, Hideto Takahashi, Haruko Noguchi, Yasuki Kobayashi
    BMJ OPEN 7(9) 2017年9月  査読有り
    Objective Changes in mortality inequalities across socioeconomic groups have been a substantial public health concern worldwide. We investigated changes in absolute/relative mortality inequalities across occupations, and the contribution of different diseases to inequalities in tandem with the restructuring of the Japanese economy. Methods Using complete Japanese national death registries from 5 year intervals (1980-2010), all cause and cause specific age standardised mortality rates (ASMR per 100 000 people standardised using the Japanese standard population in 1985, aged 30-59 years) across 12 occupations were computed. Absolute and relative inequalities were measured in ASMR differences (RDs) and ASMR ratios (RRs) among occupations in comparison with manufacturing workers (reference). We also estimated the changing contribution of different diseases by calculating the differences in ASMR change between 1995 and 2010 for occupations and reference. Results All cause ASMRs tended to decrease in both sexes over the three decades except for male managers (increased by 71% points, 1995-2010). RDs across occupations were reduced for both sexes (civil servants 233.5 to -1.9 for men; sales workers 63.3 to 4.5 for women) but RRs increased for some occupations (professional workers 1.38 to 1.70; service workers 2.35 to 3.73) for men and decreased for women from 1980 to 2010. Male relative inequalities widened among farmer, fishery and service workers, because the percentage declines were smaller in these occupations. Cerebrovascular disease and cancer were the main causes of the decrease in mortality inequalities among sexes but the incidence of suicide increased among men, thereby increasing sex related inequalities. Conclusions Absolute inequality trends in mortality across occupations decreased in both sexes, while relative inequality trends were heterogeneous in Japan. The main drivers of narrowing and widening mortality inequalities were cerebrovascular disease and suicide, respectively. Future public health efforts will benefit from eliminating residual inequalities in mortality by considering the contribution of the causes of death and socioeconomic status stratification.
  • Atsushi Miyawaki, Satoshi Toyokawa, Kazuo Inoue, Yuji Miyoshi, Yasuki Kobayashi
    PloS ONE 11(4) e0153464 2016年4月  査読有り
  • 森山 葉子, 豊川 智之, 小林 廉毅, 井上 和男, 須山 靖男, 杉本 七七子, 三好 裕司
    産業衛生学雑誌 = Journal of occupational health 54(1) 22-28 2012年1月20日  
  • 豊川智之, 村上慶子, 兼任千恵, 小林廉毅
    医療と社会 22(1) 69-78 2012年  査読有り

MISC

 24
  • Masayoshi Zaitsu, Byung Kwang Yoo, Jun Tomio, Fumiaki Nakamura, Satoshi Toyokawa, Yasuki Kobayashi
    BMC Health Services Research 18 2018年5月3日  
    © 2018 The Author(s). Background: Direct-to-consumer information (DTCI) campaign is a new medium to inform and empower patients in their decision-making without directly promoting specific drugs. However, little is known about the impact of DTCI campaigns, expanding rapidly in developed countries, on changes in prescription patterns. We sought to determine whether a DTCI campaign on overactive bladder increases the prescription rate for overactive bladder treatment drugs. Methods: We performed a 3-year retrospective cohort study of 1332 participants who were diagnosed overactive bladder but not prescribed treatment drugs prior to the examined DTCI campaign (exposure), using the health insurance claims dataset of the Japan Medical Data Center (November 19, 2010 to November 18, 2013). The DTCI campaign for overactive bladder included television, Internet, and print advertising (November 19, 2011 to December 22, 2011). We divided the study period into Pre-Campaign Year (2010-2011), Year 1 (2011-2012), and Year 2 (2012-2013). Each year began on November 19 and included Period 1 (weeks 1-5) through Period 10 (weeks 46-50). The main outcome was first-time prescription of the treatment drug for each patient, measured by 5-week periods. Using Period 10 in the Pre-Campaign Year as the referent period, we applied the Cox proportional hazard model for each period. Additionally, we performed the interrupted time series analysis (ITSA) for the first-time prescription rate per 5-week period. Results: Following the DTCI campaign, patients were about seven times more likely to receive a first prescription of a treatment drug during Period 4 in Year 1 (hazard ratio 7.09; 95% CI, 2.11-23.8; p-value<.01) compared with the reference period. Similar increases were also observed for subsequent Periods 5 and 6 in Year 1. The ITSA confirmed the DTCI campaign impact on the level of prescription rate (one-time increase in the regression-intercept) that increased by 1128.1 [per standardized 100,000 persons] (p <.05) during Period 4 in Year 1. Conclusions: The examined DTCI campaign appeared to increase the prescription rate among patients with overactive bladder for 15 weeks with a 15-week delay. Clinical outcomes of the patients with targeted diseases need to be monitored after DTCI campaigns by a future study.
  • Satoshi Toyokawa, Eri Maeda, Yasuki Kobayashi
    DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY 59(3) 317-321 2017年3月  
    AIM 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. METHOD Study participants were children and adolescents aged below 20 years, who had been assigned CP diagnosis codes more than once in claims issued between June 2012 and May 2013 from all health insurance schemes in Japan, except for Social Welfare and Elderly Health Insurance. RESULTS The number of participants with diagnosed CP was 44 381. The number of males with CP (25 237) was greater than the number of females (19 144). Peak CP prevalence per 1000 population was 2.39 at age 4 years, and this gradually declined with age. The prevalence of CP per 1000 population was 2.27 at age 5 to 9 years. The numbers of inpatients and outpatients with CP were 9126 (20.6%) and 35 255 (79.4%) respectively. INTERPRETATION Our estimation of CP prevalence per 1000 population at age 5 to 9 years lay in the higher range of figures from previous studies in Japan, and was close to figures reported by European countries.
  • Liying Pei, Satoshi Toyokawa, Yasuki Kobayashi
    JOURNAL OF OCCUPATIONAL HEALTH 59(5) 418-427 2017年  
    Objectives: There is limited evidence on the relationship between labor factors and the decision to refrain from seeking medical services. This study aimed to examine how labor factors are related to medical service access among male and female workers in Tokyo and surrounding areas. Methods: We used data from 4,385 respondents to the survey in the Japanese Study on Stratification, Health, Income, and Neighborhood (JSHINE), an ongoing epidemiologic household panel study. Surveys from 2010 to 2011 were analyzed. The outcome variable was whether or not an individual refrained from seeking medical services. Labor factors included employment type (permanent, temporary, or selfemployed), company size (< 100, 100-1,000, or > 1,000 employees) and occupation type (white-collar, blue-collar). Results: We included a total of 2,013 people after excluding those with missing data (analysis utilization: 45.9%). After adjusting covariates, we found that men working in small companies were more likely to refrain from seeking medical services than were those in medium or large companies (adjusted prevalence ratio [PR]: 1.19, 95% confidence interval [CI] : 1.04-1.37). Among women, however, those in self-employment (PR: 1.38, 95% CI: 1.08-1.77) and blue-collar employment (PR: 1.24, 95% CI: 1.04-1.47) were more likely to refrain than were those classified as permanent or white-collar workers. Conclusions: The relationship between labor factors and refraining from seeking medical services differed among men by company size, and among women by employment type and occupation type.
  • Mayumi Touyama, Jun Touyama, Satoshi Toyokawa, Yasuki Kobayashi
    BRAIN & DEVELOPMENT 38(9) 792-799 2016年10月  
    Aim: This study aimed to describe trends in CP prevalence among children born between 1988 and 2007 in Okinawa, Japan. Method: This study was conducted during two time periods, Period I (from 1988 to 1997) and Period II (from 1998 to 2007), using data from the local CP registration system. We assessed cerebral palsy gestational age and birth weight specific trends in prevalence and analyzed these with Poisson regression analysis. Results: Overall crude CP prevalence was 1.88 per 1000 live births. Approximately 70% of children with CP were born preterm or with low birth weight (LBW). Overall CP prevalence increased in Period I and decreased significantly in Period II (P < 0.05). Additionally, CP prevalence among children born with a birth weight between 1000 and 1999 g increased in Period I and decreased significantly in Period II (P < 0.05). A significant decrease was found among the children born between 1995 and 2007 with a gestational age between 28 and 31 weeks (P < 0.01). Conclusions: There was a decrease in CP prevalence from 1998 to 2007, especially among LBW children and preterm infants. The high CP proportions among LBW and preterm infants are unique features of the population of Okinawa, Japan. (C) 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
  • Masayoshi Zaitsu, Fumiaki Nakamura, Satoshi Toyokawa, Akiko Tonooka, Takumi Takeuchi, Yukio Homma, Yasuki Kobayashi
    TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 239(1) 9-15 2016年5月  
    Bladder cancer is common in Western countries, but not in Japan. Established risk factors are smoking and high-risk jobs such as printing and manufacturing. The risk of alcohol consumption in bladder cancer has been the recent focus; however, available literature on alcohol consumption and bladder cancer has been limited from Japanese population, thought to have a weak genetic tolerance to acetaldehyde. We aimed to determine whether alcohol consumption is an independent risk factor for bladder cancer among Japanese. The study was a matched case-control study from the nationwide Japanese clinical database administered by the Rosai Hospital group. We identified 739 cases of bladder cancer diagnosed between 2005 (when the database was established) and 2014 and 7,196 controls matched by sex, age, hospital, and admission period. We estimated the odds ratio of alcohol consumption for bladder cancer adjusted for the amount of smoking, high-risk occupations, and comorbidities (hypertension, hyperlipidemia, diabetes, hyperuricemia, and obesity) with conditional logistic regression. The risk of bladder cancer was significantly higher in ever drinkers than in never drinkers (odds ratio, 1.33; 95% confidence interval, 1.06 to 1.66). Furthermore, the risk threshold for alcohol consumption was more than 15 g of alcohol intake per day (one, 180-mL cup equivalent to 6 ounces of Japanese sake containing 23 grams of alcohol). Among Japanese, alcohol consumption may be an independent risk factor for bladder cancer, with a lower risk threshold.
  • Kenichi Higashi, Mitsuko Itoh, Satoshi Toyokawa, Yasuki Kobayashi
    PEDIATRICS INTERNATIONAL 58(2) 132-138 2016年2月  
    BackgroundIn Japan, the number of municipalities that offer free medical care for children has increased. This policy, however, might unintentionally aggravate the overcrowded situation of pediatric ambulatory services in Japan. We investigated the relationship between parents' health-care seeking attitudes according to child symptom severity and the amount of copayment, as well as parents' socioeconomic and demographic factors. MethodsWe used data for 4385 people from the Japanese Study of Stratification, Health, Income and Neighborhood (J-SHINE), which consisted of stratified random sampling of those aged from 25 to 50years who lived in Tokyo and neighboring areas. Outcome variables were respondent health-care seeking attitudes toward their children's mild and severe symptoms of cold. Logistic regression models were developed for each dependent variable. ResultsA total of 1606 respondents with one or more children under the age of 15years were included in the analysis. For mild symptoms of cold, no subsidy (OR: 0.51, 95%CI: 0.38-0.69) and partial subsidy (OR, 0.71; 95%CI: 0.54-0.95) were associated with fewer visit on that day answers, compared with full subsidy. Income and respondent educational level were not associated with the outcome. For severe symptoms of cold, the OR of no subsidy (0.61; 95%CI: 0.30-1.23) and that of partial subsidy (0.91; 95%CI: 0.40-2.07) were not statistically significant. ConclusionImposing a small copayment might prevent visits to medical facilities for mild symptoms of cold, but will not prevent visits for severe symptoms of cold.
  • Satoru Kamitani, Fumiaki Nakamura, Mitsuko Itoh, Takehiro Sugiyama, Satoshi Toyokawa, Yasuki Kobayashi
    BMC HEALTH SERVICES RESEARCH 15 2015年12月  
    Background: Physician maldistribution is an ongoing concern globally. The extent of medical schools retaining graduates within their geographical areas has rarely been explored in Japan or in other countries. This study aimed to investigate whether the proportion of medical school graduates practicing in the vicinity of medical school (retention rate) differs by the year of the school's establishment and by the school's funding source. Methods: This cross-sectional study used a set of databases on medical institutions and personnel. We analyzed a sample of 168,594 clinically active physicians practicing in institutions as of May 2014, who passed the National Medical Practitioners Examination between 1985 and 2013. We assessed the retention rate and the schools' establishment period and funding source (pre-1970/post-1970, private/public), using a hierarchical regression model with random intercept unique to each medical school. We used the following factors as covariates: gender, physicians' length of professional experience, and the geographical features of the medical schools. Results: The retention rate was widely distributed from 16.2 to 81.5 % (median: 48.4 %). Physicians who graduated from post-1970 medical schools were less likely to practice in the prefecture of their medical school location, relative to those who graduated from pre-1970 medical schools (adjusted odds ratio: 0.75; 95 % confidence interval: 0.62-0.90). Physicians who graduated from private medical schools were also less likely to practice in the prefecture of their medical school location, relative to those who graduated from public medical schools (adjusted odds ratio: 0.63; 95 % confidence interval: 0.51-0.77). In addition, the ability to retain graduates varied by school according to the school's characteristics. Conclusions: There was a considerable difference between medical schools in retaining graduates locally. The study results may have significant implications for government policy to alleviate maldistribution of physicians in Japan.
  • Satomi Noguchi, Satoshi Toyokawa, Yuji Miyoshi, Yasuo Suyama, Kazuo Inoue, Yasuki Kobayashi
    JOURNAL OF PUBLIC HEALTH 37(4) 605-611 2015年12月  
    Background An association between chronic oral infections and coronary heart disease has been suggested. Methods The study participants were male employees aged 36-59 years. Data were extracted from the MY Health Up Study, comprising a baseline questionnaire survey and succeeding annual health examinations for financial firm workers in Japan. Using a self-administered questionnaire at baseline, participants' oral status was classified into three types of periodontal indicators: (i) periodontal score, (ii) periodontitis and (iii) tooth loss (<5 and >= 5 teeth). An incidence of myocardial infarction (MI) was determined by annual health examination records. Results Of the 4037 candidates for follow-up in the baseline year of 2004, 3081 males were eligible for the analysis, 17 of whom experienced MI in the subsequent 5 years. The periodontal score model was associated with an increase in developing MI [odds ratio (OR) = 2.11, 95% confidence interval (CI) = 1.29-3.44], after adjusting for other confounding variables. The periodontitis (OR = 2.26, 95% CI = 0.84-6.02) and tooth loss (OR = 1.97, 95% CI = 0.71-5.45) models showed similar trends, although the difference was not significant. Conclusions Periodontal disease may be a mild but independent risk factor for MI among Japanese male workers.
  • Masayoshi Zaitsu, Satoshi Toyokawa, Akiko Tonooka, Fumiaki Nakamura, Takumi Takeuchi, Yukio Homma, Yasuki Kobayashi
    CANCER MEDICINE 4(3) 363-370 2015年3月  
    Sex differences in bladder cancer pathology and epidemiology have been the focus of recent research. We investigated the epidemiological characteristics and compared bladder cancer pathology and survival between men and women in Japan. A total of 13,184 patients with primary bladder cancer diagnosed from 1954 to 2010 were identified in a large-scale cancer registry database in Kanagawa Prefecture. Using this database, we compared the odds ratios (ORs) for nonurothelial carcinoma (non-UC) using a multiple logistic regression model adjusted for age and diagnosis periods. We also compared hazard ratios (HRs) for overall death and cancer-specific death using a Cox proportional hazards model adjusted for non-UC, age, and diagnosis period. The proportion of non-UC was significantly higher in female compared with male patients (OR=2.14, 95% confidence interval [CI]: 1.81-2.52). Furthermore, survival was significantly poorer in female patients than in male patients after adjusting for UC or non-UC (HR for overall death=1.15, 95% CI: 1.06-1.23; HR for cancer-specific death=1.39, 95% CI: 1.28-1.52). Sex differences exist in the epidemiological characteristics of bladder cancer in Japan, with female patients having less favorable pathology and poorer survival compared with male patients.
  • Chie Kaneto, Satoshi Toyokawa, Yuji Miyoshi, Yasuo Suyama, Yasuki Kobayashi
    Diabetes Research and Clinical Practice 102 138-146 2013年11月1日  
    Aim: To investigate whether long-term weight/BMI change in adulthood has a significant impact on the incidence of diabetes, independent of attained weight status. Methods: A number of 13,700 participants (2962 men and 10,738 women) aged 36 to 55 years were followed for up to 5 years using data from annual health checkups. Incident cases of diabetes were identified from self-reports or single fasting plasma glucose measurements (≥7.0. mmol/l). Weight/BMI change was calculated from participants' weight/BMI values at age 20 years and weight/BMI values at a given point during follow-up and used as a time-dependent variable in age-stratified multivariate Cox proportional hazards models. Results: During the 5 year follow-up, 408 participants (137 men and 271 women) developed diabetes. Even after adjusting for BMI during follow-up and other possible confounders, weight/BMI gain since age 20 years was significantly associated with an increased risk of developing diabetes. The hazard ratios were: 2.30 (95% confidence interval (CI): 1.31-4.04) for those who gained 6.0 to <10.0kg and 3.09 (95% CI: 1.79-5.34) for those who gained ≥10.0kg [reference: <2.0kg change]; and 2.61 (95% CI: 1.58-4.31) for those who gained 3.0 to <5.0kg/m 2 and 3.70 (95% CI: 2.22-6.16) for those who gained ≥5.0kg/m 2 [reference: <1.0kg/m 2 change]. Conclusions: The results indicate that long-term weight/BMI gain in adulthood is a significant predictor for the development of diabetes, independent of attained weight status. Because weight gain within the normal weight range could increase the risk of diabetes, non-obese people should also be warned against possible weight gain. © 2013 Elsevier Ireland Ltd.
  • Mayumi Touyama, Jun Touyama, Yasuo Ochiai, Satoshi Toyokawa, Yasuki Kobayashi
    Developmental Medicine and Child Neurology 55(5) 459-463 2013年5月  
    Aim The aim of this study was to describe the survival prognosis of children with cerebral palsy (CP) in Okinawa, Japan. Method A cohort study was conducted on all children with CP born between 1988 and 2005 in Okinawa, Japan. Survival proportions were determined with a life table and Kaplan-Meier survival curves were plotted. The effect of each predictor variable was estimated using Cox regression analysis. Results This study included 580 children with CP (332 males, 248 females). In the cohort, 119 (20.5%) children were classified in Gross Motor Function Classification System (GMFCS) level I, 65 (11.2%) were classified in level II, 40 (6.9%) in level III, 189 (32.6%) in level IV, 166 (28.6%) in level V and GMFCS level was unknown for one. Of the 34 children who died, 29 were classified in GMFCS level V and GMFCS level was unknown for one. Mean age at start of follow-up was 24.5months (SD 2.6mo) mean length of follow-up was 8years 8months (standard error of the mean 0.214y). The 5year- and 18-year survival percentages of the entire cohort were 98% and 89% respectively. In children with CP, significantly lower survival rates were associated with multiple factors, including a birthweight of at least 2500g (p=0.009), a gestational age of at least 37weeks (p=0.004), and the most severe gross motor limitation, GMFCS level V (p&lt 0.001). However, multivariate analysis showed GMFCS level V was the only significant predictor variable (p&lt 0.001) for survival of CP. Interpretation This study is the first to describe survival of children with CP in Japan. Our results are similar to those previously reported in other countries. These results are important in planning adequate provision of social and medical services for individuals with CP. This article is commented on by Day on pages 402-403 of this issue. © The Authors. Developmental Medicine &amp Child Neurology © 2013 Mac Keith Press.
  • Chie Kaneto, Satoshi Toyokawa, Kazuo Inoue, Mariko Inoue, Toshihiko Senba, Yasuo Suyama, Yuji Miyoshi, Yasuki Kobayashi
    Global journal of health science 4 42-49 2012年1月1日  
    This study aimed to investigate the association between periodontal disease and peptic ulcers in a working population. Self-administered questionnaires were distributed to all employees of a large insurance company in Japan. The questionnaire asked about their health status and lifestyle habits. Peptic ulcer was defined as either stomach ulcer, duodenal ulcer, or both. For the evaluation of periodontal disease, three indices were used: (a) loss of five or more teeth, (b) having been told of having periodontitis, and (c) periodontal risk score. Of the eligible 28 765 subjects analyzed, peptic ulcer was present in 397 (1.4%). The results of bivariate analyses showed that a significantly higher proportion of subjects with peptic ulcer reported that they lost five or more teeth (35.3 vs. 17.4%, p<0.001) or that they were told they had periodontitis (33.5 vs. 20.7%, p<0.001). Moreover, the periodontal risk score was higher for those with peptic ulcer than those without (mean 0.83 vs. 0.59, p<0.001). In multivariate logistic regression analyses, statistical associations were found between the presence of peptic ulcer and loss of five or more teeth (odds ratio (OR): 1.41, 95% confidence interval (CI): 1.13-1.76, p<0.01), having been told of having periodontitis (OR: 1.28, 95% CI: 1.03-1.59, p<0.05), and a 1-point increase in the periodontal risk score (OR: 1.17, 95% CI: 1.04-1.30, p<0.01), respectively. Modest but statistically significant associations were found between the self-reported measures of periodontal disease and peptic ulcers.
  • Satoshi Toyokawa, Yasuki Kobayashi
    SOCIAL SCIENCE & MEDICINE 71(11) 2014-2019 2010年12月  
    The geographical distribution of health professionals reflects behavioral characteristics of such professionals and of the health system in which they work. The spill-over hypothesis asserts that their oversupply leads to a more even geographic distribution. The current surplus of dentists in Japan is a suitable opportunity to observe such situations. This study demonstrates the transition of the geographic distribution of dentists from 1980 to 2000 in comparison with that of physicians. Using data from the Population Census and the Physician, Dentist, and Pharmacist Census, we calculated the ratio of dentists working in clinics and hospitals per population in 1980, 1990, and 2000 and the Gini coefficients according to the municipality boundaries at the end of 2000. We also plotted the municipalities on a graph, which illustrated the ratios of the dentists by population. We did the same analysis with physician data. The number of dentists increased by 71% during the 20 years studied. The ratios of dentists/100,000 population were 44.1, 58.3, and 69.7 in 1980, 1990, and 2000, respectively. The Gini coefficients for dentists by municipality were 0.270, 0.213, and 0.197, excluding the municipalities with a dental university or its hospital. In contrast, the Gini coefficients for physicians barely changed while the number of physicians increased by 60% during the same periods. The graphs for dentists appeared to indicate the ceiling of those ratios (approximately 100 dentists/100,000 population), but such a ceiling was not seen for physicians. The supply of dentists might have reached a level that generated the geographic diffusion and redistribution of dentists in Japan, in contrast with the situation involving physicians. This supports some results from other countries suggesting that saturation of local markets for health professionals may result in geographical redistribution, producing a more equal pattern of provision across the national space. (C) 2010 Elsevier Ltd. All rights reserved.
  • M. Inoue, S. Toyokawa, K. Inoue, Y. Suyama, Y. Miyano, T. Suzuki, Y. Miyoshi, Y. Kobayashi
    Public Health 124 530-537 2010年9月1日  
    Objectives: To investigate the effect of weight perception and lifestyle on body mass index (BMI) over a 2-year period. Study design: Longitudinal study to compare the change in BMI (kg/m2) according to weight perception and lifestyle at baseline. Methods: Study subjects were 6029 men and 18,567 women aged 20-69 years who worked at a large financial firm in Japan. Subjects' weight and height were measured in 2004 and 2006. The data in 2004 were used as baseline data. Weight perception and lifestyle factors, including eating, physical exercise, hours of sleep, smoking and alcohol consumption, were determined by a self-administered questionnaire in 2004. Results: The age-adjusted mean change in BMI over the 2-year period was -0.0593 among men and 0.0890 among women. In men, subjects who perceived themselves to be overweight had a reduced BMI 2 years later compared with subjects who perceived themselves to be 'just right' or underweight. Multiple regression analysis of lifestyle factors, adjusted for age and BMI at baseline, indicated that less time spent commuting, not having a hobby, not having a fixed lunch time, consumption of sweets, smoking and colleagues' smoking were associated with increased BMI among men. Fewer hours of sleep, no fixed lunch time and frequent soft drink consumption were associated with increased BMI among women. Conclusions: A perception of being overweight was associated with a decrease in BMI for Japanese male workers. Positive lifestyle factors associated with a decrease in BMI in both men and women include having a fixed lunch time and being older. These factors should therefore be highlighted in future health promotion activities in workplaces. © 2010 The Royal Society for Public Health.
  • Masahide Minami, Yasuki Kobayashi, Satoshi Toyokawa, Kazuo Inoue, Yasuo Takeshita
    International Heart Journal 50 457-464 2009年10月5日  
    The current study aimed to identify risk factors for atrial fibrillation (AF) detected during routine medical checkups of male workers in Japan. A nested case-control study was conducted using retrospective data from January 1998 to December 2006 collected at a hospital in Ishikawa Prefecture. Cases were those first diagnosed with AF with no record of AF events during the preceding 3 years. For each case, 2 controls were matched for age and time of medical checkup, randomly selected from among those who had not been diagnosed with AF during the same 3 years. Logistic regression was used to identify risk factors in the 3 years prior for new-onset AF. Sixty-nine cases and 138 controls were recruited; their average ages were 57.6 (SD 6.7) and 57.4 years (SD 6.7), respectively. In the logistic models, new-onset AF was associated with systolic blood pressure and drinking habits in the 3 years prior.
  • Chie Kaneto, Satoshi Toyokawa, Kazuo Inoue, Yasuki Kobayashi
    Health Policy 89 115-123 2009年1月1日  
    Objective: To investigate changes in Japanese physician workforce participation over time, with a focus on gender differences in career patterns. Methods: Subjects were Japanese physicians who had participated in the biennial national physician survey at least once between 1980 and 2002. Two cohorts of physicians were traced: those who were between 25 and 64 years old and were already on the physician registry as of 1980 (Cohort 1980), and those on the registry as of 1990 (Cohort 1990). Workforce participation rates, as measured by the proportion of physicians working in the field of health care, were calculated for every other year until 2002. Then, 10-year averages for workforce participation rates were calculated and compared by cohort and gender. Results: In both cohorts, the workforce participation rates of female physicians revealed a marked decline in their late 20s and 30s; in contrast, those of male physicians remained at a high level until the age of 65. The average workforce participation rate of female physicians was significantly lower than that of male physicians, both in Cohort 1980 and Cohort 1990, and both male and female physicians in Cohort 1990 had a significantly lower average than physicians in Cohort 1980. Conclusions: Effective measures should be taken to help physicians continue to work, and especially, to alleviate the decline in workforce participation among young female physicians. © 2008 Elsevier Ireland Ltd. All rights reserved.
  • Kazuo Inoue, Masatoshi Matsumoto, Satoshi Toyokawa, Yasuki Kobayashi
    Rural and remote health 9 1070 2009年1月1日  
    INTRODUCTION: The geographic maldistribution of physicians (their concentration in urban areas and shortage in rural areas) has long been an important political issue in post-war Japan. The aim of this study was to evaluate long-term transition in the geographic distribution of physicians, and to reveal which rural physician characteristics predict their retention in rural areas after 22 years. METHODS: A record-linkage study was conducted to extract a physician cohort by merging the 1980 and 2002 Physician Census in which all licensed physicians are legally required to register. Physician characteristics in 1980 that predicted rural practice in 2002 were identified. RESULTS: Data were used from the 93 077 physicians who were recorded in both 1980 and 2002 Physician Censuses. The number of physicians increased by 52% between 1980 and 2002. In both 1980 and 2002, the physician-to-population ratios in rural areas were approximately half that in urban areas, indicating that the physician maldistribution had not improved. In 1980, 82 414 (88.5%) physicians worked in urban areas and 10 663 (11.5%) worked in rural areas. In 2002, 76 435 (92.7%) of the 1980 urban physicians were still practicing in cities, but only 5958 (55.9%) of the 1980 rural physicians had stayed in their rural area. Logistic regression analysis showed that primary-care discipline and rural practice in 1980 positively predicted rural practice in 2002 (OR [95% CI]: 1.28 [1.23-1.35] and 16.18 [15.43-16.95], respectively). However, female sex and age in 1980 were negative predictors for rural practice in 2002 (OR [95% CI]: 0.80 [0.74-0.86] and 0.91 [0.90-0.94], respectively). CONCLUSIONS: The rapid increase of physicians between 1980 and 2002 has not substantially affected their geographic distribution. Baseline rural practice, primary care discipline and male sex of physicians were found to be predictors of rural practice after 22 years.
  • Lixin Hao, Satoshi Toyokawa, Yasuki Kobayashi
    Japanese Journal of Infectious Diseases 61 100-103 2008年5月19日  
    This study estimates the risk of viccine-associated paralytic poliomyelitis (VAPP) in Japan between 1971 and 2000. We acquired data regarding the number of VAPP cases from the website of the Ministry of Health, Labour and Welfare, and we estimated the number of oral poliovirus vaccines (OPV) administered based on the reported immunization data. Risk was calculated as the ratio between the number of VAPP cases and the number of OPV doses administered. Both the Runs test and the Poisson model were used to analyze the occurrence of VAPP. Thirty-three cases of VAPP were recorded in Japan between 1971 and 2000; approximately one case occurred per year. There were no statistical changes in temporal trends as regards the occurrence of VAPP between 1971 and 2000. The overall risk for VAPP, including both recipient and contact VAPP, was one case per 2.0 million OPV doses administered. The risk of recipient VAPP was one per 3.7 million doses, among which the first dose posed a much higher risk of one per 2.3 million than that of the subsequent dose. These data indicated that the occurrence of VAPP is rare, but the risk has remained constant for as long as OPV has been used in Japan.
  • Toshihiko Senba, Yasuki Kobayashi, Kazuo Inoue, Chie Kaneto, Mariko Indue, Satoshi Toyokawa, Yasuo Suyama, Toshiko Suzuki, Yukie Miyano, Yuji Miyoshi
    Journal of Occupational Health 50 283-287 2008年5月1日  
  • Mariko Inoue, Satoshi Toyokawa, Yuji Miyoshi, Yukie Miyano, Toshiko Suzuki, Yasuo Suyama, Kazuo Inoue, Yasuki Kobayashi
    JOURNAL OF OCCUPATIONAL HEALTH 49(5) 376-381 2007年9月  
    The objective of this study was to assess the degree of agreement between body mass index (BMI) and weight perception of Japanese office workers between the ages of 20 and 65. We sent 43,064 self-administered health-related questionnaires to all employees of a financial firm in Japan in October 2004. The questionnaire asked the respondents for their height, weight, and their weight perception. The kappa coefficient was calculated to investigate the degree of agreement between the BMI calculated using the self-reported data and weight perception for three categories. Of the questionnaires, 34,921 (81.1%) were returned and 33,514 responses (77.8%) were used for the analysis. Based on Japanese obesity criteria, 2,202 men (31.2%) and 5,145 women (19.5%) were obese; and 179 men (2.5%) and 2,769 women (10.5%) were underweight. The kappa coefficient was 0.374 for men and 0.297 for women. The kappa coefficients for different age groups-twenties, thirties, forties, fifties, and sixties (up to 65)-were respectively as follows: 0.315, 0.355, 0.374, 0.406, and 0.425 for men; and 0.194, 0.275, 0.285, 0.334, and 0.355 for women. In conclusion, the degree of agreement between BMI and weight perception differed by age and sex. The degree of agreement was smaller among women than among men and the degree of agreement among younger women was weaker than among older women.
  • TOYOKAWA Satoshi, NISHIKAWA Hiroaki, UEJI Masaru, MOTEGI Kazuo, KANO Katsumi
    Environmental Health and Preveation Medicine 41-46(1) 41-46 2001年  
    Several factors have been reported as risk factors for the development of osteoporosis. In this study, we aimed to examine the relationship among lifestyle factors, biologic factors, and bone mineral density (BMD) using structural equation modeling (SEM). The subjects in the present study consisted of 866 postmenopausal Japanese women aged between 40 and 80 years old. In the analysis by the SEM, we employed a multiple basic model. As the structural variables, lifestyle factors and biologic factors were selected. The goodness of fit index (GFI) of the final model was 0.991 and the Akaike's information criteria (AIC) showed the lowest value in the peripheral models. The degree of association between biologic factors and BMD was -0.576 (direct association), 0.012 (indirect association), and -0.564 (total association). With regard to the correlation between lifestyle factors and BMD, the degrees of association were 0.085, -0.084, and 0.001, respectively. This study defined a pilot model for factors influencing BMD. Although is remains necessary to conduct further analyses with more valid measurements and constructs, this model indicated that the correlation between BMD and lifestyle factors was lower than that between BMD and biologic factors.
  • American Journal of Epidemiology 1055-1061 1998年  
  • American Journal of Epidemiology 1055-1061 1998年  

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