Physicians In Japan Research Articles

Features of hepatitis E virus infection in humans and animals in Japan

In Japan, hepatitis E had long been considered to be a rare liver disease which can be accidentally imported from endemic countries in Asia and Africa, where the sanitation conditions are suboptimal. However, since the identification of the first autochthonous hepatitis E case and hepatitis E viremic domestic pigs in Japan in 2001, our understanding of hepatitis E virus (HEV) infection in this country has been changing markedly. This has largely been due to the development of serological and gene-based diagnostic assays, the accumulation of molecular epidemiological findings on HEV infection in humans and animals (as potential reservoirs for HEV in humans) and the recognition of the importance of zoonotic food-borne and other routes of transmission of HEV, including blood-borne transmission. Although it is now evident that autochthonous hepatitis E in Japan is far more common than was previously thought, clinical and subclinical HEV infections indigenous to Japan remain underdiagnosed and their prevalence is still underestimated due to the presence of unknown transmission routes and a low awareness of the infection status by many physicians in Japan. This review focuses on the features of HEV infection in humans and animals, as definitive or potential reservoirs for HEV, in Japan, and updates the current knowledge on the routes of transmission, including zoonotic routes, which are important for the maintenance and spread of HEV in Japan.

The National Database of Hospital-based Cancer Registries: A Nationwide Infrastructure to Support Evidence-based Cancer Care and Cancer Control Policy in Japan

Monitoring the current status of cancer care is essential for effective cancer control and high-quality cancer care. To address the information needs of patients and physicians in Japan, hospital-based cancer registries are operated in 397 hospitals designated as cancer care hospitals by the national government. These hospitals collect information on all cancer cases encountered in each hospital according to precisely defined coding rules. The Center for Cancer Control and Information Services at the National Cancer Center supports the management of the hospital-based cancer registry by providing training for tumor registrars and by developing and maintaining the standard software and continuing communication, which includes mailing lists, a customizable web site and site visits. Data from the cancer care hospitals are submitted annually to the Center, compiled, and distributed as the National Cancer Statistics Report. The report reveals the national profiles of patient characteristics, route to discovery, stage distribution, and first-course treatments of the five major cancers in Japan. A system designed to follow up on patient survival will soon be established. Findings from the analyses will reveal characteristics of designated cancer care hospitals nationwide and will show how characteristics of patients with cancer in Japan differ from those of patients with cancer in other countries. The database will provide an infrastructure for future clinical and health services research and will support quality measurement and improvement of cancer care. Researchers and policy-makers in Japan are encouraged to take advantage of this powerful tool to enhance cancer control and their clinical practice.

Activities of Private Clinic- or Hospital-Based Occupational Physicians in Japan

The present study was initiated to examine the activities of private clinic- or hospital-based occupational physicians (OPs) and to identify difficulties the OPs encountered in their occupational health service (OHS). A questionnaire was sent by mail to 557 OPs in Kyoto prefecture, Japan. Effective answers were obtained from 86 OPs who were private practitioners or physicians in hospitals and served as OPs on a part-time basis. Considering 3 h as a unit, a majority (92%) served <1 to 2 units/month. The leading fields of OHS provided by the OPs were general health examination and its follow-up, prevention of overwork, and mental health care, as well as support of workers on sick leave to return to work. OPs wished to allocate more time for maintenance and management of work and the work environment, mental health care, work area rounding, and attendance at the safety and health committee meetings. Difficulties were encountered most often in the management of mental ill health and overwork, and support of employees' return to work. Many OPs also reported difficulties with industrial hygiene-related issues such as risk assessment, and maintenance and management of work and the work environment. The present survey identified difficulties that were frequently encountered by private clinic- and hospital-based OPs in their practice of OHS; these include issues on mental health, overwork and industrial hygiene. The needs to offering OPs specific opportunities to gain information and skills in these areas are stressed.

Why are autopsy rates low in Japan? Views of ordinary citizens and doctors in the case of unexpected patient death and medical error

This article examines what could account for the low autopsy rate in Japan based on the findings from an anonymous, self-administered, structured questionnaire that was given to a sample population of the general public and physicians in Japan. The general public and physicians indicated that autopsy may not be carried out because: (1) conducting an autopsy might result in the accusation that patient death was caused by a medical error even when there was no error (50.4% vs. 13.1%, respectively), (2) suggesting an autopsy makes the families suspicious of a medical error even when there was none (61.0% vs. 19.1%, respectively), (3) families do not want the body to be damaged by autopsy (81.6% vs. 87.3%, respectively), and (4) families do not want to make the patient suffer any more in addition to what he/she has already endured (61.8% vs. 87.1%, respectively).

Attitudes toward clinical autopsy in unexpected patient deaths in Japan: a nation-wide survey of the general public and physicians

ContextAutopsy is a useful tool for understanding the cause and manner of unexpected patient death. However, the attitudes of the general public and physicians in Japan about clinical autopsy are...

Long-term management of chronic obstructive pulmonary disease: A survey of collaboration among physicians involved in pulmonary rehabilitation in Japan

This study evaluated the implementation of pulmonary rehabilitation (PR), and the extent of the collaboration between primary care and chest physicians involved in the management of chronic obstructive pulmonary disease (COPD) in Japan. The survey was conducted in 2006 via post and facsimile and included all medical institutions approved by the Japan Respiratory Society. In total, 176 institutions responded (response rate, 27%); a PR program was conducted at 55.1% of these institutions throughout Japan, but with regional differences. The mean duration of each session in an outpatient setting was 30 min with 2 sessions per week, and the mean length of hospitalization was 2-3 weeks. Although 33% of the hospitals adopted PR programs, on a scale from none (0) to maximum achievement (100), the accomplishment score was 48. Similarly, the mean satisfaction level score for collaboration was 44. The main problem arising with regards to chest physicians' referral to general physicians was the reluctance of patients or family members (88%). Chest physicians believed that general physicians should perform early screening of patients and manage early exacerbations, including educating patients of the need to discontinue smoking. Most chest physicians in Japan were not satisfied with the status of long-term COPD management. PR for COPD patients and collaboration between primary care physicians and specialists remain problematic in Japan. Moreover, there are widespread regional differences in terms of implementation. Sharing and implementing appropriate clinical information with primary care physicians according to current clinical guidelines should be emphasized.

Impact of gender-based career obstacles on the working status of women physicians in Japan

Research has shown that women physicians work fewer hours and are more likely to become inactive professionally and to switch to part-time labor, compared with their male counterparts. The published literature suggests that a gender disparity still exists in medicine which may decrease work motivation among women physicians. The authors investigated whether the experience and the perception of gender-based career obstacles among women physicians in Japan are associated with their working status (i.e., full-time vs. part-time). The present cross-sectional study is based on surveys of alumnae from 13 private medical schools in Japan conducted between June 2009 and May 2011. Of those who agreed to participate in this study, 1684 completed a self-administered questionnaire (overall response rate 83%). Experience of gender-based obstacles was considered affirmative if a woman physician had been overlooked for opportunities of professional advancement based on gender. Perception of gender-based obstacles referred to the self-reported degree of difficulty of promotion and opportunities for a position in higher education. Approximately 20% of the study participants responded that they experienced gender-based obstacles while 24% answered that they were not sure. The scores for perception of gender-based career obstacles were statistically higher among part-time workers compared with full-time workers (mean difference = 1.20, 95% CI: 0.39–2.00). Adjusting for age, marital status, the presence of children, workplace, board certification, holding a PhD degree, overall satisfaction of being a physician, and household income, stepwise logistic regression models revealed that physicians with the strongest perception of gender-based career obstacles were more likely to work part-time rather than full-time (OR, 0.59; 95% CI: 0.40–0.88). Although the experience of gender-based obstacles was not associated with working status among women physicians, the results demonstrated that a strong perception of gender-based obstacles was associated with part-time practice rather than full-time practice.

An Exploration of Barriers to Insulin Initiation for Physicians in Japan: Findings from the Diabetes Attitudes, Wishes and Needs (DAWN) JAPAN Study

ObjectiveInsulin is recommended as an appropriate treatment in type 2 diabetes patients with suboptimal glycemic control; however, its initiation is often delayed. We therefore conducted the DAWN (Diabetes Attitudes, Wishes and Needs) JAPAN study in an attempt to identify specific patient- and physician-related factors which contribute to delay of insulin initiation among Japanese patients with diabetes. In this report, we explored barriers for physicians which prevent timely insulin initiation.MethodsThe DAWN JAPAN study is a multicenter, questionnaire-based survey, conducted between 2004 and 2005. Participating physicians were categorized as follows based on their expertise: Japan Diabetes Society (JDS) certified specialists (n = 77), JDS-affiliated physicians (n = 30), and non-JDS-affiliated physicians (n = 27). To assess physician barriers to insulin initiation, we have used a newly developed 27- item questionnaire.ResultsThe mean age of patients (n = 11,656) treated by participating physicians was 64.1 years. The mean duration of diabetes was 121.6 months, and their mean HbA1c was 7.5%. Insulin was used in 27.4% of total patients. With regard to physician barriers to insulin initiation, the biggest differences in concerns expressed by JDS-certified specialists and non-JDS-affiliated physicians were observed in the following items with statistical significance: “I do not have staff (nurse, pharmacists) who can assist with explanations” (1.3% vs 55.5%, respectively), “I have concerns about the use of insulin therapy in elderly patients” (38.1% vs 81.5%), and “It is difficult to provide guidance and education on insulin injection to patients” (16.9% vs 55.5%). The mean HbA1c at which physicians responded they would recommend insulin to their patients was 8.7%; however, they would reduce this level to 8.2% if they themselves required insulin.ConclusionsOur results demonstrated that physicians have concerns about insulin use, and suggested that their concerns can lead to delay of insulin initiation.

A global template for reforming residency without work-hours restrictions: Decrease caseloads, increase education. Findings of the Japan Resident Workload Study Group

Background: Japanese physician training programs are currently not subject to rigorous national standardization. Despite residency restructuring in 2004, little is known about the current work allocation of residents in Japan.Aims: We quantified the amount of time that Japanese junior residents spend in service versus education in the context of caseload, fatigue, and low-value administrative work.Methods: In this prospective, time-and-motion study, the activity of 1st- and 2nd-year residents at three Japanese community hospitals was observed at 5-min intervals over 1 week, and categorized as patient care, academic, non-patient care, and personal. Self-reported sleep data and caseload information were simultaneously collected. Data were subanalyzed by gender, training level, hospital, and shift.Results: A total of 64 participating residents spent substantially more time in patient care activities than education (59.5% vs. 6.8%), and little time on low-value, non-patient work (5.1%). Residents reported a median 5 h of sleep before shifts and excessive sleepiness (median Epworth score, 12). Large variations in caseload were reported (median 10 patients, range 0–60).Conclusions: New physicians in Japan deliver a large volume of high-value patient care, while receiving little structured education and enduring substantial sleep deprivation. In programs without work-hour restrictions, caseload limits may improve safety and quality.

わが国の産業医の平成14年から20年までの就退職数とその特徴

Recently, the number of occupational physicians has greatly increased compared to other types of physician in Japan, and the number of unfilled job vacancies remains high, suggesting a higher turnover of occupational physicians. Job turnover and seniority are important indices for measuring the balance of vacancies and applicants, as well as for improving occupational health services; however, job turnover and career moves of occupational physicians are currently not known. Based on a component model study of physicians, dentists and pharmacists, we made a component model of 4 levels (national, prefectural, urban, and municipal levels) and estimated the turnover and regional migration of occupational physicians. As a reference for the component models, we used the 2008/2006 cross-tabulation data of each type of physician published by the Ministry of Health, Labour and Welfare. The municipality level component model fitted the data best. The increase in occupational physicians for the 2 yr was 283-348, and the decrease was 202-222, indicating that 55-65% of occupational physicians quit their post within 2 yr. The propensity for short tenure is observed not only in occupational medicine, but also in emergency and rehabilitation medicine. It is suspected that 80% of new occupational physicians, except those graduating from the University of Occupational and Environmental Health, quit their positions within two years. This is a remarkably short tenure period compared to the 5.6 yr average seniority of physicians reported in the Basic Survey of Wage Structure. The reasons for the high job turnover of occupational physicians are thought to be unrelated to income or license renewal. We need to survey the actual reasons for the short tenure of occupational physicians to provide insights into lifetime education and career organization of occupational physicians.

Usage and attitudes of physicians in Japan concerning traditional Japanese medicine (kampo medicine): a descriptive evaluation of a representative questionnaire-based survey.

Kampo medicine has been the primary medical model in Japan until the mid 1800s, regained a prominent role in today's Japanese medical system. Today, 148 herbal Kampo formulas can be prescribed under the national health insurance system, allowing physicians to integrate Kampo in their daily practice. This article aims to provide information about the extent to which Kampo is now used in clinics throughout Japan and about physician's current attitudes toward Kampo. We used the results of a 2008 survey that was administered to physicians throughout Japan (n = 684). The data showed that 83.5% of physicians currently use Kampo in the clinic, although the distribution of physicians who use Kampo differ widely depending on the specialty and provided a breakdown of Kampo usage by specialty. It will be interesting to see how each specialty incorporates Kampo into its respective field as Kampo continues to play a pertinent role in Japanese medical system.

A broken heart: repair needed?

At the recent meeting of the American Heart Association (Orlando, Florida, USA, November 2011) two interesting studies on a broken heart were presented. The first study was conducted by Dr. Abhishek Deshmukh at the University of Arkansas, USA and addressed patients with Takotsubo cardiomyopathy, also known as the broken heart syndrome [1, 2]. It was shown that women are 7–9 times more likely to suffer from the broken heart syndrome than men. Takotsubo cardiomyopathy may happen when sudden or prolonged stress such as an emotional breakup or death causes overwhelming heart failure or heart attack-like symptoms. The syndrome was first recognised about 20 years ago by physicians in Japan and occurs when a great emotional shock, even a positive one, induces a burst of adrenaline and other stress hormones that cause the left ventricle to balloon suddenly with ensuing cardiac dysfunction. The Arkansas University study analysed records from a nationwide database in 2007. It was found that of 6230 patients with broken heart syndrome, 90% were women. In addition, in patients over 55 years, the chance of developing broken heart syndrome was 9.5 times higher in women than in men. Consequently, hormonal differences or coronary artery variations may act as causative mechanisms. Fortunately, almost all patients with Takotsubo cardiomyopathy recovered spontaneously without permanent cardiac damage in need of (aggressive) repair. The second study on a broken heart, the Stem Cell Infusion in Patients with Ischemic cardiomyopathy (SCIPIO) study, was presented by Dr. Roberto Bolli (Louisville, Kentucky, USA). The study was conducted in patients with ischaemic cardiomyopathy and addressed the question whether patients’ own stem cells may be used to reverse cardiac damage. The SCIPIO study is an ongoing clinical trial which addressed post-MI patients who received infusions with cardiac stem cells that had been harvested from their own hearts during coronary artery bypass surgery. Patients with post-MI left ventricular dysfunction (LVEF ≤40%) before bypass surgery were randomly assigned to treatment or the control group (2:3 ratio). One million autologous cardiac stem cells were administered by intracoronary infusion 4 months after bypass surgery, whereas the control group received no treatment. The primary endpoint was short-term safety of cardiac stem cells and the secondary endpoint was feasibility. Sixteen patients were assigned to the treatment group and seven to the control group. In 14 patients with ischaemic cardiomyopathy who underwent bypass surgery, LVEF improved from 30.3% to 38.5% (P = 0.001), whereas in seven control patients the LVEF did not change (30.1% vs. 30.2 ± 2.5%). In seven stem cell patients who underwent cardiac MRI, the investigators observed a significant 24% decrease in infarct size at 4 months. It was concluded that intracoronary infusion of autologous cardiac stem cells was effective in improving left ventricular function and reducing infarct size in patients with heart failure after myocardial infarction. The results of the SCIPIO trial were published in The Lancet by Early Online Publication, on 14 November 2011. The data of the SCIPIO trial are encouraging and suggest that, if the correct cell type is used, this approach may be effective in patients with reduced cardiac function. The SCIPIO trial is the first study of autologous cardiac stem cells in humans. However, data are based on an interim analysis from an ongoing study and additional patients and follow-up will be needed to confirm these impressive preliminary results [3–5]. Anyway, the afore-mentioned studies show that broken hearts are capable of repair, be it spontaneously (Takotsubo cardiomyopathy) or by using cardiac stem cells (ischaemic cardiomyopathy).

Association of current work and sleep situations with excessive daytime sleepiness and medical incidents among Japanese physicians.

The aim of the present study was to clarify the current work and sleep situations of physicians in Japan and to clarify the association between these situations and excessive daytime sleepiness as well as medical incidents. A self-administered questionnaire survey was conducted among the members of the Japan Medical Association in 2008. The randomly selected subjects comprised 3,000 male physicians and 1,500 female physicians. Valid responses were obtained from 3,486 physicians (2,298 men and 1,188 women). Mean sleep duration was 6 h 36 min for men and 6 h 8 min for women. The prevalence of lack of rest due to sleep deprivation was 30.4% among men and 36.6% among women; the prevalence of insomnia was 21.0% and 18.1%, respectively; and the prevalence of EDS was 3.5%. The adjusted odds ratio for EDS was high for physicians who reported short sleep duration, lack of rest due to sleep deprivation, and a high frequency of on-call/overnight work. Physicians who had experienced a medical incident within the previous one month accounted for 19.0% of participants. The adjusted odds ratio for medical incidents was high for those subjected to long working hours, high frequency of on-call/overnight works, lack of rest due to sleep deprivation, and insomnia. In order to facilitate optimal health management for physicians as well as securing medical safety, it is important to fully consider the work and sleep situations of physicians.

Urbanization and physician maldistribution: a longitudinal study in Japan.

BackgroundThe relative shortage of physicians in Japan's rural areas is an important issue in health policy. In the 1970s, the Japanese government began a policy to increase the number of medical students and to achieve a better distribution of physicians. Beginning in 1985, however, admissions to medical school were reduced to prevent a future oversupply of physicians. In 2007, medical school entrants equaled just 92% of their 1982 peers. The urban annual population growth rate is positive and the rural is negative, a trend that may affect denominator populations and physician distribution.MethodsOur data cover six time points and span a decade: 1998, 2000, 2002, 2004, 2006, and 2008. The spatial units for analysis are the secondary tier of medical care (STM) as defined by the Medical Service Law and related legislation. We examined trends in the geographic disparities in population and physician distribution among 348 STMs in Japan. We compared populations and the number of physicians per 100,000 populations in each STM. To measure maldistribution quantitatively, we calculated Gini coefficients for physician distribution.ResultsBetween 1998 and 2008, the total population and the number of practicing physicians for every 100,000 people increased by 0.95% and 13.6%, respectively. However, the inequality of physician distribution remained constant, although small and mostly rural areas experienced an increase in physician to population ratios. In contrast, as the maldistribution of population escalated during the same period, the Gini coefficient of population rose. Although the absolute number of practicing physicians in small STMs decreased, the fall in the denominator population of the STMs resulted in an increase in the number of practicing physicians per population in those located in rural areas.ConclusionsA policy that increased the number of physicians and the physician to population ratios between 1998 and 2008 in all geographic areas of Japan, irrespective of size, did not lead to a more equal geographical distribution of physicians. The ratios of physicians to population in small rural STMs increased because of concurrent trends in urbanization and not because of a rise in the number of practicing physicians.

Japanese Resident Physicians' Attitudes, knowledge, and Perceived Barriers on the Practice of Evidence Based Medicine: a Survey.

BackgroundEvidence based medicine plays a crucial role as a tool that helps integrate research evidence into clinical practice. However, few reports have yet to examine its application in daily practice among resident physicians in Japan. The aim of this study was to assess the attitudes towards and knowledge of EBM among resident physicians in Japanese and determine perceived barriers to its use.FindingsA cross-sectional, self-administered anonymous questionnaire was distributed to 60 resident staffs at Saga University Hospital in Japan.Forty residents completed and returned the questionnaire. Fifty four percent of respondents understood the basic terminology of EBM, 3% could explain this to others, and 41% indicated they would like to understand the terminology more. Thirteen percent admitted having a good understanding of EBM basic skills. Fifty respondents indicated having read EBM sources, but only 3% indicated that they use these sources in clinical decision making. The most prominent barriers of EBM application revealed in this study were insufficient time to access the sources, a lack of native language references, and insufficient basic EBM skills, but not scepticism about the EBM concept.ConclusionsIn general, respondents positively welcomed EBM, and moderately understood and knew basic EBM skill; however, barriers in its application were shown to exist.

Survey of Japanese pediatricians on vaccination of children with neurological disorders

Primary care physicians in Japan are often unwilling to vaccinate children with neurological disorders. The aim of the present study was to determine the state of vaccination in children who are severely handicapped and/or have convulsive disorders, in order to increase the vaccination rate in this patient population. Six hundred and eighty pediatricians belonging to Osaka Shonika Ikai were asked to answer a questionnaire, and 359 doctors responded. Two hundred and thirty-four doctors consulted for febrile seizures (Fs), 190 for epilepsy and 145 for conditions affecting severely handicapped children, responded that they refused to vaccinate. The reasons for reluctance to vaccinate these children were short interval since the last seizure, including febrile (226 doctors) and epileptic (121 doctors) seizures. It was especially likely that a child with a past history of status epilepticus would be refused vaccination. Primary care doctors are very cautious about the indications for vaccination, especially the inoculation of live vaccines, because they often induce post-vaccination fever-associated convulsions. Intractable daily epileptic seizures was the most common reason for refusal to vaccinate severely handicapped children. Examples of inadequate decision-making as regards the indications for vaccination were: "need more than 6 months observation since last seizure whether Fs or epileptic", "need EEG examination for Fs", "contraindication because of low bodyweight and/or chronic wheezing in severely handicapped children". There is a need to provide correct information about the adverse effects of vaccination and for greater cooperation between primary care doctors and pediatric neurologists.

Successful neutrophil engraftment by reduced use of granulocyte colony-stimulating factor after allogeneic hematopoietic stem cell transplantation with mycophenolate mofetil for graft-versus-host disease prophylaxis

In allogeneic hematopoietic stem cell transplantation (allo-SCT), most physicians in Japan utilize granulocyte colony-stimulating factor (G-CSF) at a high dose (HD) of 300 μg/m(2) per day for filgrastim to promote faster neutrophil engraftment. However, the necessity of the HD has not been validated under graft-versus-host disease (GVHD) prophylaxis by mycophenolate mofetil (MMF), which can also be expected to facilitate engraftment. In a total of 51 patients, we compared the clinical outcomes between a standard dose (SD) fixed at 300 μg per day and a HD of G-CSF. While time to neutrophil engraftment was not different in the HD and SD groups in patients receiving cord blood transplantation (CBT, 20 vs. 17.5 days, P = 0.243) or bone marrow transplantation (BMT, 11 vs. 10 days, P = 0.227), there seemed to be an increased risk of developing acute GVHD in the HD group with CBT (20 vs. 0%, P = 0.073) and BMT (57 vs. 24%, P = 0.165). Progression-free survival of patients in the HD group was likely to be worse compared with that of the SD group with CBT (P = 0.099). In this study, the clinical benefits of a HD of G-CSF could not be documented, and we find that the use of G-CSF at a SD after allo-SCT with MMF should be prospectively evaluated.

Opinion of Japanese rheumatology physicians on methods of assessing the quality of rheumatoid arthritis care

To examine the opinion of rheumatology physicians in Japan regarding desirable quality assessment methods. We conducted a cross-sectional self-administered mail survey on a random sample of physicians and surgeons registered with the Japan Rheumatism Foundation. In the survey, respondents were asked to rank seven proposed assessment methods for the quality of rheumatoid arthritis care, namely patient satisfaction, risk-adjusted outcomes such as complication incidence and admission rate, guideline compliance, waiting time at clinics, voting by local general practitioners, degree of newspaper and magazine reportage, and volume of patients receiving treatment for rheumatoid arthritis. Among 531 respondents (response rate 48%), the respondents ranked patient satisfaction most favourably (mean rank 1.6), followed by complication/admission rate and number of patients. Guideline adherence was ranked almost the same as voting by local physicians. Waiting time and media reportage were not considered good methods for quality evaluation. Ranking distribution did not differ by working facility or place, volume of patients or years in practice. Multivariate analysis revealed that respondents who care for a large number of rheumatoid arthritis patients (>40 regular patients) were less likely to rank guideline adherence highly (first to third) than those who care for few patients (≤ 10 regular patients), with an odds ratio of 0.38 (P < 0.01) after adjustment for other variables. A majority of Japanese rheumatology physicians consider patient satisfaction the most trustworthy method of assessing the quality of rheumatoid arthritis care. Future research should explore convincing methods of assessing the technical quality of rheumatoid arthritis care.

Factors associated with working among female physicians in Japan

Factors associated with working among female physicians in Japan

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.