Hiroshi Une

Urbanization and physician maldistribution: a longitudinal study in Japan

BackgroundThe relative shortage of physicians in Japans 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.

Adiponectin levels associated with the development of hypertension: a prospective study.

Adiponectin is a recently discovered protein that seems to be exclusively secreted by adipocytes and is the most abundant adipose tissue–derived protein. While some recent studies have demonstrated an association between adiponectin levels and hypertension, these studies were cross-sectional in design, and the results have been inconsistent. Therefore we performed a prospective study to elucidate the role of adiponectin in the development of hypertension. The results of this study showed that serum adiponectin levels were significantly lower in hypertensive subjects than in normotensive subjects. Moreover, in logistic regression analysis, the subjects in the lowest quartile had a 3.72-fold higher risk than those in the highest quartile. Even after adjusting for potential confounding factors, this association was found to be significant. Low serum adiponectin levels were found to be independently associated with a higher risk for the development of hypertension. Our results therefore suggest that hypoadiponectinemia is a novel predictor of hypertension.

Infectious waste management in Japan: A revised regulation and a management process in medical institutions

Abstract In Japan, the waste management practice is carried out in accordance with the Waste Disposal Law of 1970. The first rule of infectious waste management was regulated in 1992, and infectious wastes are defined as the waste materials generated in medical institutions as a result of medical care or research which contain pathogens that have the potential to transmit infectious diseases. Revised criteria for infectious waste management were promulgated by the Ministry of Environment in 2004. Infectious waste materials are divided into three categories: the form of waste; the place of waste generation; the kind of infectious diseases. A reduction of infectious waste is expected. We introduce a summary of the revised regulation of infectious waste management in this article.

The effect of the interaction between obesity and drinking on hyperuricemia in Japanese male office workers.

Background Obesity and drinking are acknowledged risk factors for hyperuricemia. However, the effect of the interaction between obesity and drinking on hyperuricemia is not well understood. Methods The cases comprised 3028 male office workers with hyperuricemia (serum uric acid level ≥7.0 mg/dL); the controls were 5348 men with a serum uric acid level less than 6.0 mg/dL. Logistic regression analysis was used to assess risk factors for hyperuricemia and the interaction between obesity and drinking in hyperuricemia. Participants were divided into 2 groups according to their BMI: individuals with a BMI of 25 or higher were classified as obese and those with a BMI less than 25 were classified as non-obese. In addition, participants were divided into 5 groups based upon their ethanol consumption. The 2 variables were then combined to create 10 groups. Results With non-obese non-drinkers as the reference category, the odds ratio for hyperuricemia was 1.80 for non-obese drinkers of less than 25 mL/day of ethanol, 2.15 for non-obese drinkers of 25–49 mL/day, 2.60 for non-obese drinkers of 50–74 mL/day, 2.56 for non-obese drinkers of 75+ mL/day, 4.40 for obese non-drinkers, 5.74 for obese drinkers of less than 25 mL/day, 6.57 for obese drinkers of 25–49 mL/day, 5.55 for obese drinkers of 50–74 mL/day, and 7.77 for obese drinkers of 75+ mL/day. The interaction between obesity and drinking in hyperuricemia was statistically significant. Conclusion Our results suggest that although combining the effects of obesity and drinking did not result in a multiplicative increase in the risk for hyperuricemia, the combined risk was greater than the sum of the effects of obesity and drinking.

EFFECTS OF AN INCREASE IN PATIENT COPAYMENTS ON MEDICAL SERVICE DEMANDS OF THE INSURED IN JAPAN

OBJECTIVES To examine quantitatively the effects of an increase in patient copayments from 10% to 20% on the demand for medical services in Japan. METHODS The subjects of the study were the employees insured by the 1,797 health insurance societies, belonging to the National Federation of Health Insurance Societies, in 1996 and 1998. Indicators of medical service demands analyzed include the inpatient, outpatient, and dental case rates, the number of serviced days per case, the medical cost per day and the medical cost per insured. RESULTS When the effects of an increase in patient copayments from 10% to 20% were evaluated, taking into account the average age, the average monthly salary, the total number, the gender (male-to-female) ratio and the dependent ratio of the insured, the estimated change in the case rate was -6.96% for inpatient, -4.79% for outpatient, and -5.77% for dental care. The estimated change in the number of serviced day per case was -4.66% for inpatient, -5.67% for outpatient, and -1.82% for dental care. The estimated change in the medical cost per day was -3.15% for inpatient, -13.00% for outpatient, and -11.48% for dental care. The estimated change in the medical cost per insured was -14.08% for inpatient, -21.54% for outpatient, and -18.11% for dental care. CONCLUSIONS The increase in patient copayments from 10% to 20% enabled insurers to substantially reduce medical costs by cost shifting from the insurer to the insured, with resultant changes in the case rate and the number of service days per case.

A statistical analysis of 'rule-out' diagnoses in outpatient health insurance claims in Japan.

BACKGROUND As each clinical procedure must be justified by a corresponding diagnosis in Japanese health insurance claim (HIC), unconfirmed diagnoses marked as rule-out diagnoses will be written on an HIC. However, little is known about the statistical profiles of such rule-out diagnoses. OBJECTIVES To illustrate the basic statistical profiles of rule-out diagnoses. METHODS We analysed all the diagnoses on 169 622 outpatient HICs in May 2006 from corporate health insurance societies. The proportions of additional diagnoses and rule-out diagnoses in each of the major disease categories defined by the Classification of Diseases for the use of Social Insurance, which is based on the International Statistical Classification of Diseases and Related Health Problems 10th Revision were calculated. RESULTS There were 442 010 diagnoses on the HICs, of which 96 253 (21.8%) were principal diagnoses and 345 757 (78.2%) were additional diagnoses. Of the principal diagnoses, 1022 (1.1%) were rule-out diagnoses. Of the additional diagnoses, 19 308 (5.6%) were rule-out diagnoses. The percentage of rule-out diagnoses in the additional diagnosis category was significantly higher than that in the principal diagnosis category. Among the major disease categories, neoplasms showed the highest percentage of rule-out diagnoses for both principal diagnosis and additional diagnosis. CONCLUSIONS The existence of rule-out diagnoses affects the results of statistics based on HIC data. Japanese statistics based on HIC data should be improved by utilizing the information on rule-out diagnoses.

Risk of Lung Cancer among Japanese Coal Miners on Hazard Risk and Interaction between Smoking and Coal Mining

Risk of Lung Cancer among Japanese Coal Miners on Hazard Risk and Interaction between Smoking and Coal Mining: Motonobu Miyazaki, et al. Department of Hygiene and Preventive Medicine, School of Medicine, Fukuoka University—This article examines whether an association is found between lung cancer and coal mining and also whether a correlation is found between smoking and coal mining that relates to the risk of lung cancer in Japanese coal miners. A cohort study was performed in former coal mine areas. The survey was carried out between 1987 and 1989, and was extended in a follow‐up period to 1995. 5,818 Japanese males (1,796 coal miners and 4,022 non‐coal miners) aged from 40 to 69 yr responded to a mail questionnaire that included occupational history and smoking habits. The data were analysed with Coxs proportional hazards model. Significant differences in hazard ratios for lung cancer were recognized in coal miners with >15yr of work (Hazard ratio=2.08, 95% Cl: 1.01‐4.27) and current smokers with >20 cigarettes/day (Hazard ratio=5.41, 95% Cl: 1.26‐23.28). As regards the interaction of coal mining and smoking, the hazard ratios were 2.04 (95% Cl: 0.13‐32.83) for coal miners who had never smoked, 4.71 (95% Cl: 0.62‐35.56) for non‐coal miners who were ex‐smokers or current smokers, and 6.88 (95% Cl: 0.92‐51.65) for coal miners who were ex‐smokers or current smokers compared with non‐coal miners who had never smoked. The interaction of coal mining and smoking for the risk of lung cancer was likely to be additive rather than synergistic.

Evaluating measles surveillance: comparison of sentinel surveillance, mandatory notification, and data from health insurance claims

Inadequate notification is a recognized problem of measles surveillance systems in many countries, and it should be monitored using multiple data sources. We compared data from three different surveillance sources in 2007: (1) the sentinel surveillance system mandated by the Act on Prevention of Infectious Diseases and Medical Care for Patients Suffering Infectious Diseases, (2) the mandatory notification system run by the Aichi prefectural government, and (3) health insurance claims (HICs) submitted to corporate health insurance societies. For each dataset, we examined the number of measles cases by month, within multiple age groups, and in two categories of diagnostic test groups. We found that the sentinel surveillance system underestimated the number of adult measles cases. We also found that HIC data, rather than mandatory notification data, were more likely to come from individuals who had undergone laboratory tests to confirm their measles diagnosis. Thus, HIC data may provide a supplementary and readily available measles surveillance data source.

Is heat shock protein 60 associated with type 2 diabetes mellitus

AIMS HSP60 plays a protective role against heat, oxidative injury and ultraviolet. Recently, animal and clinical studies have suggested that HSP60 plays a role in various diseases. However, few epidemiological studies have demonstrated an association between HSP60 levels and type 2 diabetes mellitus. Therefore, an epidemiological study was conducted to examine the association of HSP60 with type 2 diabetes mellitus. METHODS This study included 83 type 2 diabetes mellitus patients and 161 controls that were recruited from male employees who received annual health check-ups between 2005 and 2007. The serum HSP60 levels were measured using the ELISA method. RESULTS Because the HSP60 levels were not detectable (<3.125 ng/mL) in 48.0% of the study subjects, HSP60 levels were divided into two categories (detectable or undetectable). A logistic regression analysis showed that the subjects in the undetectable had a 2.03 times higher risk of diabetes mellitus than those in the detectable after adjustment for age, BMI and rate of hypertension medication. CONCLUSIONS This study was the first epidemiological study to demonstrate an association between type 2 diabetes mellitus and HSP60, thus suggesting that HSP60 may play an important role in the type 2 diabetes mellitus pathology.

A comparison of disease‐specific medical expenditures in Japan using the principal diagnosis method and the proportional distribution method

BACKGROUND There are technical limitations to handling all the information mentioned in health insurance claims (HICs) in Japan. Therefore, conventional methods for estimating disease-specific medical expenditures assume that all medical care expenditures in a given HIC are spent on only one principal diagnosis even when the HIC contains multiple diagnoses. OBJECTIVES To estimate the disease-specific medical expenditures that consider all diagnosis on a given HIC. METHODS Data were obtained from 169 622 outpatient HICs in May 2006 from health insurance provided by the employer. We compared the estimated disease-specific medical expenditures of the conventional method with a proportional distribution method (PDM), which considers all diagnoses on the HICs. RESULTS For diabetes mellitus and other diseases of the digestive system, the proportion of principal diagnoses among total diagnoses was 52.4% (4849/9251) and 19.6% (2614/13331), respectively. In addition, the ratio of the estimated disease-specific medical expenditures between the conventional method and the PDM method was 1.49 for diabetes mellitus and 0.64 for other diseases of the digestive system. The estimation of disease-specific medical expenditures using the conventional method may therefore have overestimated the expenditures on the disease category typically selected as the principal diagnosis and underestimated the expenditures on the disease category less likely to be selected as the principal diagnosis. CONCLUSIONS The conventional method for estimation of disease-specific medical expenditures should be improved by utilizing all the diagnoses information on HICs.