Satoshi Toyokawa

Geographical distributions of physicians in Japan and US: Impact of healthcare system on physician dispersal pattern

OBJECTIVES This study examined the effect of increased physician numbers overall on the geographic distribution of the physicians in Japan and the US. METHODS Equity of physician distribution with reference to community population and community income was evaluated in all municipalities in Japan, and all counties in the US. RESULTS Between 1980 and 2005, Japan and the US experienced a 55% and 47% increase in the number of physicians per unit population, respectively. The Gini coefficients against population were at similar values between Japan and the US, and have been almost unchanged in the past 25 years in both countries. The Gini coefficient against income in the US was lower than the coefficient in Japan, and the US value has decreased since 1980. Correlation between physician-to-population ratio and per capita income among the communities was stronger in the US than in Japan and has increasingly been strengthened during the period examined. CONCLUSIONS In spite of constant growth of physician numbers, physicians do not diffuse according to population distribution in both countries. Rather, US physicians seem to diffuse according to income distribution. In order to reverse the continuing maldistribution of physicians, political intervention is required in both countries.

Degree of agreement between weight perception and body mass index of Japanese workers: MY Health Up Study.

Degree of Agreement between Weight Perception and Body Mass Index of Japanese Workers: MY Health Up Study: Mariko Inoue, et al. Department of Public Health, Graduate School of Medicine, University of Tokyo—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.

Association of periodontitis with increased white blood cell count and blood pressure.

This study aimed to examine the association of periodontitis with white blood cell (WBC) count and blood pressure (BP). In 2002, 424 subjects (manufacturing workers) were investigated for periodontitis by a general dentist. All were Japanese. Among them, 364 subjects (269 men and 95 women) who also attended the next years (2003) screening were enrolled for this study. Of the 364 subjects, 55 (15.1%) had periodontitis. We also measured the BP and WBC count in periodontitis and non‐periodontitis subjects at baseline and 1‐year later follow‐up. The WBC count was higher in subjects with periodontitis than in subjects without periodontitis, both at baseline [mean±standard error (SE) 6.6×103±0.2×103/ml vs 5.8±0.3×103/ml; p<0.001] and follow‐up (7.0±0.3×103/ml vs 6.5±0.1×103/ml; p = 0.03). The systolic BP was higher in subjects with periodontitis than in subjects without periodontitis, both at the baseline (128.8±2.1 mmHg vs 120.8±0.8 mmHg; p<0.001) and follow‐up (129.2±2.3 mmHg vs 123.0±0.8 mmHg; p = 0.011), and so was the diastolic BP both at baseline (76.1±1.5 mmHg vs 71.2±0.6 mmHg; p = 0.003) and follow‐up (80.5±1.7 mmHg vs 75.4±0.7 mmHg; p = 0.004). Periodontitis is associated with increased BP and WBC count. This finding may provide one underlying pathway linking periodontitis and cardiovascular disease.

Secondary Neoplasms After Retinoblastoma Treatment: Retrospective Cohort Study of 754 Patients in Japan

OBJECTIVE Little is known about the incidence of secondary neoplasms among survivors of retinoblastoma in Japan. The objective of our study was to analyze the cumulative incidence rate of secondary neoplasms following retinoblastoma and to investigate the risk factors of developing secondary neoplasms. METHODS We conducted a retrospective cohort study of 754 retinoblastoma patients who visited the National Cancer Center Hospital in Tokyo between 1964 and 2007. The cumulative incidence rate curves were drawn using the competing risk method and compared with the Grays test. Using competing risk regression analysis, multivariate analysis estimated the subdistribution hazard ratio of factors related to the development of secondary neoplasms. RESULTS The median length of follow-up was 108 months (0-594 months). Twenty-one (2.8%) patients developed 23 secondary neoplasms in total. The cumulative incidence rates of secondary neoplasms after retinoblastoma treatment were 2.4% at 10 years after diagnosis, 4.3% at 20 years, 6.4% at 30 years and 19.1% at 40 years. Ten patients (1.3%) died and 723 (95.9%) were alive without developing secondary neoplasms. The subdistribution hazard ratios of hereditary retinoblastoma and external beam irradiation were 4.85 (95% confidence interval = 0.74-31.85) and 4.76 (95% confidence interval = 0.69-33.09), respectively. CONCLUSIONS We demonstrated the cumulative incidence rate of secondary neoplasms following retinoblastoma in Japan. The subdistribution hazards ratios of hereditary retinoblastoma and external beam irradiation were high but not significant because of statistical power. The long-term follow-up of retinoblastoma survivors is warranted to understand secondary neoplasm risk.

Increasing supply of dentists induces their geographic diffusion in contrast with physicians in Japan

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.

Quality of care for diabetes patients using National Health Insurance claims data in Japan

BACKGROUND Assessment of the quality of care is a key element in current diabetes care. However, the quality of care for diabetes patients in Japan has rarely been reported. OBJECTIVES To assess the quality of diabetes care in two communities in Japan by using National Health Insurance claims data. METHODS We analysed claim data of 13,650 beneficiaries of National Health Insurance in two communities in Japan from May 2006 to April 2007. Diabetes cases were identified by using a case detection algorism. Our main outcome measures were three process quality indicators: (1) haemoglobin A1c (HbA1c) testing; (2) annual eye examination; and (3) annual nephropathy screening, recommended in the existing clinical guidelines. We calculated the performance rate of each quality indicator and examined the effects of demographic characteristics and co-morbid conditions. RESULTS We identified 636 diabetes cases. Of these, 97.0% had at least one HbA1c test, and 69.8% had ≥ 4 tests during the study period. The odds ratios (ORs) for ≥ 4 HbA1c tests were lower in subgroups aged 75-79 (OR 0.58, 95% confidence interval 0.35-0.96), and aged ≥ 80 (OR 0.54, 95% confidence interval 0.32-0.88) compared with the subgroup aged <70 after adjusting for other patient characteristics. The annual rate for eye examinations and nephropathy screenings were 20.8% and 5.8% respectively. CONCLUSIONS We found high performance rates for HbA1c testing, while the annual rates for eye examinations and nephropathy screenings were suboptimal. Using administrative data would facilitate more comprehensive assessment of the quality of care in Japan.

Gender difference in physician workforce participation in Japan.

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.

Relevant Obstetric Factors for Cerebral Palsy: From the Nationwide Obstetric Compensation System in Japan.

Objective The aim of this study was to identify the relevant obstetric factors for cerebral palsy (CP) after 33 weeks’ gestation in Japan. Study design This retrospective case cohort study (1:100 cases and controls) used a Japanese national CP registry. Obstetric characteristics and clinical course were compared between CP cases in the Japan Obstetric Compensation System for Cerebral Palsy database and controls in the perinatal database of the Japan Society of Obstetrics and Gynecology born as live singleton infants between 2009 and 2011 with a birth weight ≥ 2,000 g and gestation ≥ 33 weeks. Results One hundred and seventy-five CP cases and 17,475 controls were assessed. Major relevant single factors for CP were placental abnormalities (31%), umbilical cord abnormalities (15%), maternal complications (10%), and neonatal complications (1%). A multivariate regression model demonstrated that obstetric variables associated with CP were acute delivery due to non-reassuring fetal status (relative risk [RR]: 37.182, 95% confidence interval [CI]: 20.028–69.032), uterine rupture (RR: 24.770, 95% CI: 6.006–102.160), placental abruption (RR: 20.891, 95% CI: 11.817–36.934), and preterm labor (RR: 3.153, 95% CI: 2.024–4.911), whereas protective factors were head presentation (RR: 0.199, 95% CI: 0.088–0.450) and elective cesarean section (RR: 0.236, 95% CI: 0.067–0.828). Conclusion CP after 33 weeks’ gestation in the recently reported cases in Japan was strongly associated with acute delivery due to non-reassuring fetal status, uterine rupture, and placental abruption.

Sex differences in bladder cancer pathology and survival: analysis of a population-based cancer registry

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.

Access to antiretroviral therapy among HIV/AIDS patients in khon kaen province, Thailand

This study attempted to identify the factors associated with the access to antiretroviral therapy (ARV) among HIV/AIDS patients in Khon Kaen Province, Thailand. We collected medical and sociodemographic data from the medical charts of adult patients living in the province who received medical services at two public hospitals in the province. The study period was from December 1 2001 to February 28 2002. Total 593 outpatients were included in the analysis. One hundred and forty-six patients (24.6%) received ARV. A logistic regression analysis was conducted to identify the factors associated with the use of ARV. Patients who were covered by the Civil Servant Medical Benefit Scheme were significantly more likely to receive ARV than those who were covered by the Universal Coverage Scheme (UC), a publicly-funded medical insurance (OR=12.43; 95% CI=6.03–25.62). The results of this study indicated that there were inequalities in access to and use of ARV among HIV/AIDS patients by health insurance status. The current government announced that they would include ARV in the benefits package of UC. It would be important to monitor how this policy will improve the access to ARV among HIV/AIDS patients.