Estimation of the incidence of MRSA patients: evaluation of a surveillance system using health insurance claim data.

Because sentinel surveillance systems cannot obtain information about patients who visit non-sentinel medical facilities, the characteristics of patients identified by these systems may be biased. In this study, we evaluated the representativeness of a methicillin-resistant Staphylococcus aureus (MRSA) surveillance system using health insurance claim (HIC) data, which does not depend on physician notification. We calculated the age-specific incidence of MRSA patients using data from the Japan Nosocomial Infections Surveillance (JANIS) programme, which is based on sentinel surveillance systems, and inpatient HICs submitted to employee health insurance organizations in 2011, and then computed age-specific incidence ratios between the HIC and JANIS data. Age-specific MRSA incidence in both datasets followed J-shaped curves with similar shapes. For all age groups, the ratios between HIC and JANIS data were around 10. These findings indicate that JANIS notification of MRSA cases was not affected by patients' age.

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.

Coffee consumption but not green tea consumption is associated with adiponectin levels in Japanese males.

PURPOSE: Coffee is among the most widely consumed beverages in the world. Numerous epidemiological studies have reported a significant inverse association between coffee consumption and risk of type 2 diabetes mellitus, but the underlying mechanisms are still not fully understood. Therefore, we conducted an epidemiological study to clarify the relationship between coffee consumption and adiponectin levels in Japanese males. We also evaluated whether green tea consumption affected adiponectin levels. METHODS: We carried out a cross-sectional study. The subjects were 665 male employees in Japan. Coffee consumption was assessed, using a self-administered questionnaire, as the number of times per week and cups per day respondents drank, and subjects were grouped into four levels (non, 1-5 times/week, 1-2 cups/day and ≥3 cups/day). RESULTS: The means of adiponectin levels were positively associated with coffee consumption. A dose-response relationship was found between coffee consumption and circulating adiponectin levels. The relationship remained significant after adjustment for potential confounding factors (P for trend <0.05). However, green tea consumption was not significantly associated with adiponectin levels (P for trend = 0.90). CONCLUSIONS: We not only revealed that habitual coffee consumption is associated with higher adiponectin levels in Japanese males but also found a dose-dependent association between coffee consumption and adiponectin levels. Therefore, our study suggested that coffee components might play an important role in the elevation of adiponectin level.

Changes in epidemic patterns of Kawasaki disease in Japan.

OBJECTIVE: Clustering of cases of Kawasaki disease throughout Japan was noted three times during the period before 1986. During the ensuing 10 years, however, no nationwide epidemic has been recognized. The purpose of this study is to test the hypothesis that local outbreaks have persisted after 1987. METHOD: The data on 56 980 patients reported from 1987 through 1996 were classified according to the area of residence. The time trend of the incidence rate was compared by year and by quarter of the year (January to March, April to June, July to September and October to December) in 10 geographical areas in Japan. RESULTS: No nationwide outbreaks have been noted since 1987 in Japan, but the existence of local outbreaks of various magnitudes was recognized as occurring in different periods in certain areas. The incidence rates were continuously high in Area 1 between 1987 and 1988 and in Area 4 between 1995 and 1996. In Area 9 local outbreaks were noted on three separate occasions (from 1987 to the first half of 1988, between 1990 and 1991 and from the second half of 1992 to 1993). No clusterings were witnessed in other areas during the 10-year period. CONCLUSION: The current annual number of patients ranges from 5000 to 6000, and local epidemics occur in various areas. The current epidemiologic patterns support the infection theory for the etiology of this disease.

Specific alcoholic beverage and blood pressure in a middle-aged Japanese population: the High-risk and Population Strategy for Occupational Health Promotion (HIPOP-OHP) Study.

The purpose of this study was to clarify the effects of popular Japanese alcoholic beverages on blood pressure. We performed a cross-sectional study on 4335 Japanese male workers using baseline data from an intervention study. We defined six groups according to the type of alcoholic beverage that provided two-thirds of the subject's total alcohol consumption: beer, sake (rice wine), shochu (traditional Japanese spirits), whiskey, wine and others. The partial regression coefficients of daily alcohol intake (1 drink=11.5 g of ethanol) to systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 0.87(P<0.001, standard error (s.e.)=0.09) and 0.77(P<0.001, s.e.=0.06), respectively. A comparison among the types of alcoholic beverages mainly consumed revealed significant differences in SBP and DBP. Both SBP and DBP were highest in the shochu group. However, an analysis of covariance adjusting for total alcohol consumption resulted in the disappearance of these differences. Although after adjustment for total alcohol consumption, the shochu group exhibited a significant positive association with 'high-normal blood pressure or greater' (odds ratio 1.43, 95% confidence interval 1.06-1.95) compared with the beer group, this significant relation disappeared after adjusting for the body mass index (BMI), urinary sodium and potassium excretion. The pressor effect, per se, of popular Japanese alcoholic beverages on blood pressure may not be different among the types of alcoholic beverages after adjusting for other lifestyle factors.

[Estimation of the future numbers of patients with diabetes mellitus in Japan based on the results of national patient surveys].

The projected numbers of patients with diabetes mellitus (ICD 9th; 250) 15 years from now were estimated. First, the numbers of patients with the disease in 1984, 1987, 1990, and 1993 were calculated by age and sex using data from the National Patient Surveys conducted by the Ministry of Health and Welfare. Then, population prevalence for calendar years 1996, 1999, 2002, 2005, and 2008 were estimated based on the past data using linear regression models. Finally, the total numbers of patients were calculated from the estimated prevalence multiplied by the estimated population figure of the national government. The prevalence and the numbers of patients are estimated to increase, and the numbers will be 1.7 million among males and 1.5 million among females in 2008. Besides, because of the increases of both the aged population and the disease prevalence, the proportion of patients aged 65 years or over will become as large as 40% of total male patients and 60% of females.

[Chronological trend of the incidence rate of Creutzfeldt-Jakob disease in Japan].

OBJECTIVE: The purpose of this study was to find whether the number of incidents of Creutzfeldt-Jakob disease has increased during the last decade in Japan. METHODS: The chronological trend was observed by examining the data from a nationwide epidemiologic survey conducted by a special committee sponsored by the Ministry of Health and Welfare of Japan in May 1996. The subjects of the survey were patients with Creutzfeldt-Jakob disease who had been diagnosed between January 1985 and May 1996. Although the number of patients reported each year increased continually during the 11-year 5-month period, there were two issues that remained to cast doubt on the accuracy of this apparently obvious chronological trend: (1) the existence of hospitals that did not respond to the survey, and (2) the existence of hospitals where no information was available before a specific time during the observation period. To make up for the incomplete data, the following two methods were proposed: (1) for those hospitals where the precise annual incidence was not known, the average annual incidence for those years when the information was available should be used to make up for the missing data and (2) when a hospital did not have the information for certain years, it would be considered to be a nonrespondent for those years; the response rate should be calculated year-by-year; then the total number of patients should be obtained by the reported number of patients divided by the response rate. The first method underestimates the annual trend if a trend does exist. To evaluate the trend mathematically, linear regression and quadratic regression models were used, in which the independent variable was the calendar year, the dependent variable, the number of patients. RESULTS: With either method, a trend for increases in incidence was noted. Statistical significance was obtained for the increasing trend in each model. It was found that the quadratic regression model was a better fit than the linear model. CONCLUSION: The incidence of Creutzfeldt-Jakob disease in Japan has increased during the last decade.

[Building aging level indices based on ability to perform personal care and household management activities].

Defining aging as deterioration of the ability required for the activities of daily living with increasing age, we developed a formula for estimating the age of aging. In 1994 and 1995, a questionnaire survey was conducted for 11,592 individuals (4,885 men, mean age 61.6, standard deviation 14.6; and 6,677 women, mean age 63.2, standard deviation 14.8) who were members of 7 cohorts (5 community-based cohorts and 2 cohorts of examiners at a health-promotion center). The questionnaire included three groups of questions related to medical treatment, aging-related symptoms, and personal care (ADL; Activities of Daily Living) and household management (IADL: Instrumental ADL). Multiple regression analysis was made by sex and age group (over 65 years old, under 65 years old) using age as a dependent variable and the three question categories as explanatory variables. Using multiple regression analysis by question category, five items were abstracted from each of the three groups, so that a total of 15 items were abstracted from all questions. Five items were then abstracted from the 15 by multiple regression analysis, and the predicted aging age for an individual is estimated using this statistical model from the results of the questionnaire survey. The predicted aging age is significantly associated with age (r = 0.40-0.49, p = 0.0001). The difference between the predicted aging age and age is greater among the older or younger people. The expected predicted aging age is estimated using regression analysis of the predicted aging age on age. Aging level indices by sex and age groups were determined by the difference between the expected predicted aging age and age. We are planning to carry out an epidemiological study on the risk factor for aging using the aging level indices in seven cohorts.

[Geographical distribution of medical expenditure for the aged insured by National Health Insurance in secondary medical care areas in Japan].

PURPOSES: To determine what factors affect medical expenditure for the aged insured by the National Health Insurance among secondary medical care areas. METHOD: The original data of municipalities were combined and converted into the data of secondary medical areas. The original data included medical expenditure of the aged in 1994, medical supply factors per 100,000 population (numbers of doctors, numbers of general beds in hospitals, numbers of clinics, etc.) and socio-economic factors (income, proportion of employees for three sectors of industries, population density, average size of family, etc.). Medical expenditures for inpatients and outpatients were used separately as independent variables. The medical supply and socio-economic factors have been used as dependent variables. Multiple regression models were applied to clarify the differences in the contributing factors between inpatient and outpatient. RESULTS: 1. The maximum inpatient and outpatient medical expenditures for the aged are respectively 4 times and 2.6 times more expensive than minimum expenditures among secondary medical care areas. 2. The numbers of beds, income per capita, numbers of doctor, average size of family, proportion of employees for third level industry and income accounted for 57.4% of variance in inpatient medical expenditure of the aged. 3. The proportion of employees for first level industry, the numbers of beds and average members of family accounted for 21.4% of variance in outpatient medical expenditure of the aged. 4. Medical expenditure for inpatients related with medical supply and socioeconomic factors differently from that of outpatients.

[Estimation of the future numbers of patients with circulatory diseases in Japan based on the results of national patient surveys].

The numbers of patients aged 35 years or more with hypertension, ischemic heart disease, and cerebrovascular disease 15 years from now were estimated. First, the numbers of patients with these diseases in 1984, 1987, 1990, and 1993 were calculated by age and sex using data from the National Patient Surveys conducted by the Ministry of Health and Welfare. Then, population prevalence for calendar years 1996, 1999, 2002, 2005, and 2008 were estimated based on the past data using linear regression models. Finally, the total numbers of patients were calculated from the estimated prevalence multiplied by the estimated population figure of the national government. The numbers of patients with hypertension will decrease in younger age classes but increase in older age classes; the total number of all patients, therefore, will increase. While the number of patients with ischemic heart disease in males is estimated to increase, that in females will level off. The number of cerebrovascular disease patients in each age and sex group will grow larger.

[Family intervention for schizophrenia based on expressed emotion (EE) research: a review of the technique and evaluation].

The present study reviews eight series of trials on psycho-social family intervention for schizophrenia based on Expressed Emotion (EE). All studies used randomized controlled trials (RCT) except one which was non-randomized controlled trial. The relapse risk ratios (intervention/control) for 9-12 months after discharge were 0 to .73 and for 24 months were .20 to .57. Taking into account the shortcomings of the studies, the authors conclude that psycho-social family intervention based on EE is effective in preventing schizophrenic relapse, and discuss four important issues: 1) For effective family intervention, methods for Japanese patients should be established from a trans-cultural view point; 2) The interaction of two or more therapeutic measures should be evaluated quantitatively; 3) The mechanisms of schizophrenic relapse prevention through family psycho-social intervention should be explored. A psycho-physiological study including skin conductance measurement is promising; 4) The authors point out the ethical aspect of family intervention, and discuss the importance of informed consent and the need to place emphasis on family's needs.

[Geographic distribution of medical supplies and the numbers of hospital inpatients in the secondary medical areas in Japan].

A secondary medical area is defined as a medical administrative area under the Medical Care Law by which every prefectural government is expected to provide general medical care supplies such as beds for inpatients. This study evaluated the distribution in medical supplies among the secondary medical areas in Japan and the correlation between medical supply and demand. The numbers of hospital inpatients (residence of patients), physicians, and general beds excluding those for mental disorders and tuberculosis were analysed in relation to the population in all secondary medical areas in Japan. Those data were obtained from surveys conducted by the Ministry of Health and Welfare. The main results were as follows; 1) The distribution of physicians and general hospital beds among the secondary medical areas was not equal. 2) Even adjusted for the sex and age distribution, the highest hospital inpatients/population ratio among the secondary medical areas was four times as large as that of the lowest. 3) With multiple regression models, two independent variables (normal hospital beds/population ratio and aged 65 and over/total population ratio) accounted about 60% of the variance in hospital inpatients/population ratio. 4) The differences in medical supplies among the secondary medical areas may cause the differences in hospital inpatients/population ratio.

[Case-control study of risk factors for cedar pollinosis among parents of 3-year-old children].

PURPOSE: To identify risk factors associated with cedar pollinosis among parents of three-year-old children. METHODS: The subjects were parents whose children underwent health examination at the age of three years in September and October 1997 in Tochigi prefecture. We distributed questionnaires to the examinees beforehand with the request that they be filled in and brought to the examination site. Information on parents' environmental factors (place of residence, type and structure of housing, and distance from roads with heavy traffic), and mothers' past history and family history of allergic diseases was obtained. We defined cedar pollinosis in terms of three symptoms, sneezing, nasal discharge, and nasal obstruction, between February and May. Controls were those who did not have any of the three symptoms. Environmental factors were assessed with univariate and multivariate analyses using unconditional logistic models. Maternal genetic factors were also analyzed with odds ratios and 95% confidence intervals calculated for each. We also compared odds ratios of environmental factors between groups with and without genetic factors. RESULTS: Of the parents of children taking the health examination, 90.2% took part (2,968 of 3,291 couples). Information was obtained from 2,846 mothers and 2,905 fathers. Mother and father cases were 312 and 229, and controls were 1,857 and 1,934, respectively. For the univariate analysis of environmental factors, place of residence (residential area/agricultural area), type of housing (apartment complex/solitary house), structure (reinforced concrete building/wooden house), and distance from heavy traffic (< 100 m/100 m+) were positively related to cedar pollinosis. For the multivariate analysis using unconditional logistic models, the odds ratio was significantly high for distance from heavy traffic (< 100 m/100 m+) among fathers. Mothers' past history and family history of allergic diseases showed high odds ratios for cedar pollinosis. We classified groups with and without past and family histories of allergic diseases (group with and without genetic factors) for assessment with multivariate analyses. Odds ratios for the group with an allergic history were higher than for those without such a history, but difference for factors such as, distance from heavy traffic type of housing, and structure were not statistically significant. CONCLUSION: Risk of cedar pollinosis increases with distance from heavy traffic among fathers. Mothers with histories of allergy show slightly elevated odds ratios for environmental factors, but without statistic significance.

[Relationship between breast milk and atopic dermatitis in children].

OBJECTIVE: To determine whether or not dioxins and furans in breast milk have a role in the prevalence of atopic dermatitis among children. METHODS: The target population of the study was all children participating in health check-up program for 3-year-old children in Tochigi Prefecture in September and October 1997. Using a questionnaire, information on nutrition in infants (breast milk only, bottled milk only, or mixed), parity, mothers' age at birth, and a history of atopic dermatitis was obtained. Besides, data on potential confounding factors were obtained. RESULTS: Questionnaires from 2,968 children (85.3% of those who were to participate in the programs, and 90.2% of children who participated them) were analyzed. The risk of atopic dermatitis was higher among children with breast milk (odds ratio [OR] = 1.37 with 95% confidence interval [CI] 1.02-1.83) and those with mixed nutrition (OR = 1.21, 95% CI: 0.94-1.57) in comparison with children with only bottled milk. Mothers' age at birth (OR for those who were more than 30 years or older in comparison with those who were younger than 30 years = 1.27; 95% CI, 1.01-1.62) and those with second or later parity orders (OR = 1.32, 95% CI; 1.04-1.67) were also risk factors of the dermatitis after the adjustment for some potential confounding factors. CONCLUSION: Breast milk elevates the risk of atopic dermatitis slightly; the risk is, however, higher in children in second or later parity orders. If the PCDDs and PCDFs in breast milk cause the dermatitis, this would contradict the assumed metabolism of these chemicals in human bodies.

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.

Family history evaluation in epidemiologic studies; an evaluation of bias in the conventional methods and a proposal of a new one.

We discuss problems of conventional methods to evaluate family histories as risk factors in epidemiologic studies, and propose a new one. In the proposal, incidence rates of the disease interested among family members are treated as exposure levels. Besides, we show the quantitative difference between the results obtained by the conventional methods and the new one using models. Because of not so much information required for the new method, we recommend it even though the difference was not so large.

Repeatability of the questionnaire for the aging level indices.

The purpose of the study is to confirm repeatability of the series of self-administrating questions, which can be applied in large community populations. In 1994 and 1995, two surveys were conducted for the residents at Minamikawachi, Japan with a same questionnaire. The number of respondents for the both surveys was 887. Kappa statistics of all items of the series of questions for aging level indices were significantly high. Kappa statistics were over 0.4, and repeatability is good or excellent in 28 items of all the 45 items. The statistics of the items for medical treatments of chronic diseases were high, in such as diabetes (0.846) and hypertension (0.604). For activity of daily livings, such as shopping (0.619), kappa statistics were also high, but that of eating (0.162) was low. The statistics of subjective symptoms were moderate, however, that of impairment of hearing (0.672) was high, and that of decline of interest in opposite sex (0.256) were low. On the other hand, kappa statistics of acute diseases were low, in such as bone fracture (0.073). Correlation coefficients of the comprehensive aging level indices are around 0.6 among the people of 65 years old or older. In conclusion, the repeatability of the questions and indices were good, and they are appropriate to apply to communities.

Estimation of the future numbers of patients with mental disorders in Japan based on the results of National Patient Surveys.

To estimate the future numbers of patients with mental disorders, schizophrenic disorders, and neurotic disorders, prevalence obtained from the National Patient Surveys conducted by the Ministry of Health and Welfare of the Japanese government was projected by using linear models by age and sex. The prevalence of whole mental disorders and neurotic disorders will increase, while that of schizophrenic disorders will not do so much. The numbers of patients with mental disorders were estimated to be 973 thousand for males and 1,359 thousands for females in the year of 2008, which were 622 thousand and 733 thousand in 1993, respectively. The disease-specific numbers in 2008 were 562 thousand for schizophrenic disorders and 867 thousand for neurotic disorders, both were 451 and 437 thousand in 1993, respectively. Because of the increase of old age population, the number of old patients with each disorder will also become large.

Results of the nationwide epidemiologic survey of Kawasaki disease in 1995 and 1996 in Japan.

OBJECTIVE: The objective of the study is to describe recent epidemiologic patterns of Kawasaki disease based on information included in patient records that had been obtained through a nationwide hospital survey in Japan. METHODS: A questionnaire and diagnostic criteria for Kawasaki disease that had been approved by the Kawasaki Disease Research Committee were sent to all pediatric departments of hospitals (2638 hospitals) with a bed capacity of at least 100. The subjects all were new patients who were treated during a 2-year period from 1995 to 1996. RESULTS: A total of 12 531 children contracted the disease during the observation period. The incidence was 102.6 for 1995 and 108.0 for 1996 per 100 000 children younger than age 5 years. The male:female ratio was 1.37. The age distribution pattern showed a peak near 6 months of age. Geographic variations in the incidence suggested the existence of local outbreaks. Cardiac sequelae were seen in 12% of the patients. CONCLUSION: More than 6000 patients suffered from Kawasaki disease each year, and its annual incidence is increasing steadily. The probable existence of local outbreaks is worthy of note. Other epidemiologic patterns were unchanged from previous years.