Biomedical subjects

Kazuhiko Ohe

Publications and source records attributed to Kazuhiko Ohe.

18 recordsLinked to original sources

PubMed2006

Price differences between Japan and the US for medical materials and how to reduce them.

INTRODUCTION: Previous reports (1996, 1997) have revealed that the market prices of medical materials in Japan were two to four times higher than those in the US. The Japanese government introduced the foreign price adjustment rule (FPA) in 2002 to reduce reimbursement prices in Japan. We aimed to investigate the current price differences between Japan and the US in the first half of 2005 and to evaluate the effectiveness of the FPA. METHODS: The investigation was performed at two joint purchasing organizations (JPO) and a hospital group in the US, and at a university hospital in Japan. Forty-one items in 14 categories were selected in advance. RESULTS: The price ratio (Japanese price/US price) was largest at 4.5-6.8 for percutaneous transluminal coronary angioplasty (PTCA) balloon catheters and 1.4-6.0 for vascular grafts. The price ratio was smallest at 1.2-2.4 for automatic sutures, 1.4-1.6 for Swan-Ganz catheters, and 1.5-2.3 for mechanical valves. DISCUSSION: The price differences between Japan and the United States were found to have rather widened with the exception of the pacemaker, because their market prices decreased more markedly in the United States. The investigation suggests several problems with the FPA: (1) the determination process of reimbursement prices is inappropriate, which has made the Japanese market less competitive, (2) the FPA needs too much time for the resolution of price differences, and (3) price data collected according to the FPA lacks strictness. CONCLUSIONS: The high prices of medical material in Japan need to be adjusted down with more appropriate measures such as the full cost or cost inclusion methods.

Commerce↗

PubMed2006

Building a reference functional model for EHR systems.

INTRODUCTION: Our aim was to develop a reference functional model for electric health record systems (RFM). Such a RFM is built from functions using functional descriptive elements (FDEs) and represents the static relationships between them. This paper presents a new format for describing electric health record (EHR) system functions. METHODS: Questionnaire and field interview survey was conducted in five hospitals in Japan and one in the USA, to collect data on EHR system functions. Based on survey results, a reference functional list (RFL) was created, in which each EHR system function was listed and divided into 13 FDE types. By analyzing the RFL, we built the meta-functional model and the functional model using UML class diagrams. The former defines language for expressing the functional model, while the latter represents functions, FDEs and their static relationships. RESULTS: A total of 385 functions were represented in the RFL. Six patterns were found for the relationships between functions. The meta-functional model was created as a new format for describing functions. Examples of the functional model, which included the six patterns in the relationships between functions and 11 verbs, were created. DISCUSSIONS: We present the meta-functional model, which is a new description format for the functional structure and relationships. Although a more detailed description is required to apply the RFM to the semiautomatic generation of functional specification documents, our RFM can visualize functional structures and functional relationships, classify functions using multiple axes and identify the similarities and differences between functions. The RFM will promote not only the standardization of EHR systems, but also communications between system developers and healthcare providers in the EHR system-design processes.

Japan↗

PubMed2006

Women's anxieties caused by false positives in mammography screening: a contingent valuation survey.

BACKGROUND: Breast cancer screening with mammography has been shown to be effective for preventing breast cancer death. However, mammography screening can be harmful to women. One of the major problems is anxiety from a false positive result. Previous studies do not consider intangible benefits related to anxiety or peace of mind in mammography screening. In order to quantify anxiety, we employed the contingent valuation method (CVM) to measure the general public's willingness to pay (WTP) for mammography screening. METHODS: About 397 women aged 50-59 participated in the computer-assisted questionnaire survey. For the WTP question format, the double-bound dichotomous choice approach was employed. Participants were randomly assigned into 2 groups. Group A (n = 200) was provided with information about the procedure, detection rate and mortality reduction of mammography screening. Group B (n = 197) was provided with additional information including possibility of false positives and the risks of close examinations. RESULTS: The mean WTP was significantly greater in Group A than in Group B ($16.82 vs. $12.89, P = 0.02). A Weibull regression analysis showed that, type of information, history of receiving mammography screening, family history of cancer, and the degree of concern about health were significant factors affecting WTP. CONCLUSIONS: Women must be well informed before making decisions about mammography screening. Although anxiety from information about false positives significantly decreased the women's benefit, the amount of WTP in the well-informed group was still considerable. The results suggest that women can balance the anxiety against the effectiveness.

Anxiety↗

PubMed2006

Willingness to pay for health care services in common cold, retinal detachment, and myocardiac infarction: an internet survey in Japan.

BACKGROUND: The application of Willingness To Pay (WTP) measurement with Contingent Valuation Method (CVM) to medical services is gradually increasing. Knowing what influences WTP is an important matter because validity of CVM in medical services remains controversial. The objective of this survey is to measure WTP for the treatment of typical acute illnesses and to analyze the factors affecting WTP. METHODS: A questionnaire survey was conducted over the Internet, in which 795 men and women between 40 and 59 years old responded to questions about WTP for medical expenses in three hypothetical scenarios: common cold (CC), retinal detachment (RD) and myocardiac infarction (MI). RESULTS: Mean WTP was $29.9 for CC, $2,233 for RD, and $8,976 for MI. WTP for RD and MI was lower in the low-income group. While WTP for CC did not vary with income, WTP was higher in groups whose current subjective fitness levels were low. CONCLUSION: Although WTP measurements are criticized frequently for their validity and reliability, they are still useful for determining the economic value of medical services. Based on the results of this study, it is deemed necessary to enhance safety nets for low-income earners in regards to serious illnesses that incur high medical expenses. Further, it is recommended that the rate of co-payments be set relatively high with respect to mild illnesses for which alternative services are available.

Adult↗

PubMed2006

The measurement of willingness to pay for mass cancer screening with whole-body PET (positron emission tomography).

OBJECTIVE: Recently, we have seen an increase in the number of studies that measured the willingness to pay (WTP) for medical services using the contingent valuation method (CVM) and evaluated the benefits of these services. This study aimed to measure the general public's WTP for cancer screening with positron emission tomography (PET) and to determine consumer characteristics that may affect their WTP. METHODS: A questionnaire survey of males and females living in Japan aged between 40 and 59 years was conducted via the Internet. A total of 274 individuals accepted the offer to participate and were enrolled in the study. The study participants were divided into two groups: Group A (n = 138) and Group B (n = 136). Group A was provided only with information about the PET procedure and the high cancer detection rate; Group B was provided with additional information regarding the possibility of 'false negative' and 'false positive' results and the fact that the efficacy of PET screening for reducing mortality has not yet been demonstrated. Participants were then asked to answer their WTP for cancer screening with PET by paymentcards approach. RESULTS: The overall average amount consumers were willing to pay for PET cancer screening was dollars 103.7 (n = 274). The average value in Group A was dollars 107.3, the average value in Group B was dollars 100.0 and there was no statistically significant difference between the groups. The results of categorical regression analysis showed that household annual income was the only significant factor affecting WTP. CONCLUSIONS: Our study showed that household annual income affected the WTP for cancer screening with PET and therefore the demand for PET screening would be limited to the high-income group. Negative information about PET did not reduce the WTP. This finding suggests that test subjects mainly evaluated the high detection rate of PET screening and the 'reassurance' value of receiving negative screening results.

Adult↗

PubMed2006

Benefit evaluation of mass screening for prostate cancer: willingness-to-pay measurement using contingent valuation.

OBJECTIVES: Cancer screening exists to save lives. However, the mortality-reducing effect of prostate cancer screening has not yet been sufficiently demonstrated. Therefore, screening should only be performed in men well informed about the disease. We hypothesized that having sufficient information will reduce men's desire for screening. To verify this hypothesis, we measured the willingness to pay (WTP) for prostate-specific antigen screening using the contingent valuation method. METHODS: A computer-based questionnaire was implemented through the Internet for 137 men in Japan aged 40 to 59 years. Participants were randomly assigned to two subgroups: 69 subjects were provided with information about the detection rate, and 68 were provided with additional information such as the failure to demonstrate the mortality-reducing effect of prostate-specific antigen screening to date. All were asked about their WTP by a payment cards approach. RESULTS: The mean WTP for prostate-specific antigen screening was 18.90 dollars. Categorical regression analysis suggested that annual income, age, and hospitalization history were factors affecting the WTP. Unexpectedly, the difference in the mean WTP between the ill-informed and well-informed groups was not statistically significant. CONCLUSIONS: The contingent valuation method can quantify comprehensive benefits, including not only health outcomes, but also non-health outcomes such as reassurance value. The subjects were not so concerned about the long-term effectiveness of saving lives. Their greatest concern was the detection rate. Their WTP may have reflected their desire for the reassurance that could be obtained by confirming that they had no physical sign of cancer.

Adult↗

PubMed2006

Analysis of factors affecting willingness to pay for cardiovascular disease-related medical services.

Recently, application of the contingent valuation method (CVM) to health care is increasing to measure the willingness to pay (WTP) for specific medical services. In this study, we measured WTP for the outpatient treatment of hypertension and inpatient treatment of myocardial infarction (MI) in Japan's healthcare system, using CVM via an Internet questionnaire survey in 547 citizens aged 40 to 49 years. WTP was measured with the payment cards method from an ex post consumer based perspective. The payment vehicle was out-of-pocket copayment under public medical insurance. The participants were asked their preferences with respect to medical institutions, and 3 comprehensive characteristics were extracted from the requested information by principal component analysis. Categorical regression was performed to analyze the factors affecting WTP. The mean WTP for hypertension treatment was 75.03 dollars/month, and that for the treatment of MI was 8,928.70 dollars (1 dollar = 105 Japanese yen). WTP for hypertension treatment was significantly high in married males and the group without symptoms, but was not associated with income. WTP for the treatment of MI was significantly high in the high-income group, married males, and the group with symptoms. Among the 3 principle components, "objective evaluation" was significantly associated with WTP for the treatment of MI. As for serious diseases such as MI, the income-associated differences in WTP suggest the necessity for reinforcement of the safety net for the low-income group. Although asymptomatic, hypertension requires continuous treatment. For such diseases, uniformly low copayment should be established irrespective of annual income.

Adult↗

PubMed2006

[Medical research using Internet questionnaire in Japan].

As the method for questionnaire studies, mail survey and interview survey are frequently used. The utility and validity of applying the Internet method to medical studies have yet to be fully evaluated. For the present investigation, we reviewed 36 Japanese original articles using Internet questionnaire reported through to April 2005. Although original papers using the Internet method have been increasing in recent years, they are still limited in number. There is comparatively much research on disease with many patients in youth and early manhood, such as allergic ailments (allergic rhinitis, atopic dermatitis, and hives). As compared with conventional methods, the advantages of the Internet approach are convenience for both investigators and respondents and the ability to quickly collect data. The disadvantage is that the user's age range is more concentrated. Since samples are extracted from individuals who are registered as monitors, a greater sampling error may occur as compared with a random sampling method. However, it is to be expected that continued explosive growth of the Internet would decrease the limitation in user's age. If more elderly people participate in questionnaire studies using the web, research into more illnesses should be facilitated. Considering the inherent advantage, it is thought that Internet method can become the leading tool for sociomedical and clinical research in the near future.

Adolescent↗

PubMed2006

[Contingent valuation for health care services. Review of domestic studies and outline of foreign investigations].

Contingent valuation method (CVM) can be applied to measure benefits of healthcare services. It is a technique for estimating subjects' willingness to pay (WTP) for a service under the scenario describing a virtual market with a questionnaire. In the present research, we outlined foreign studies and reviewed domestic studies on healthcare contingent valuation. A total of 14 papers from domestic literature (five English and nine Japanese articles) identified with mechanical search engines were verified for the following eight items: the method of the questionnaire; the information included in the virtual scenario; the question form for the willingness to pay; bias problems specific to CVM; validity/reliability, ex post/ex ante valuation, altruistic WTP, and non-health value. The following conclusions were drawn from the domestic studies: (1) several studies were short of sufficient information regarding the virtual scenario; (2) no research proved the existence of bias and the ways of coping with it; (3) tests for reliability were not carried out, although some kind of validity was verified; (4) all involved ex post user based evaluation; (5) neither altruistic WTP nor non-health value was examined. Taken the advantages of CVM into consideration, it should become a useful tool, complementing other economic evaluation techniques. Since its application has just begun in Japan, more emphasis needs to be given to practical issues so that healthcare workers will utilize CVM in a way that domestic studies in health economics will be activated.

Attitude to Health↗

PubMed2005

The electrical properties of epidural catheters: what are the requirements for nerve stimulation guidance?

We designed the present study to investigate the electrical resistance of commercially available epidural catheters and to search for products and procedures suitable for nerve stimulation-guided insertion. Four types of epidural catheters were evaluated: 2 nonwire-reinforced catheters (19-gauge and 20-gauge nylon) and 2 wire-reinforced catheters (19-gauge without stylet and 20-gauge with stylet). The resistance of a catheter was calculated from the voltage level proportional to the fixed resistance in series circuit. In case of physiologic saline, the resistance of nonreinforced catheters was more than 700 kOmega, whereas the wire-reinforced catheter was 14.4 +/- 0.20 kOmega without stylet and 10.1 +/- 0.42 kOmega with stylet. When the stylet was passed through a 20-gauge nylon catheter, the resistance decreased to 49.2 +/- 1.96 kOmega. When catheters were primed with 10% hypertonic saline, the resistance of both nonreinforced catheters decreased by one third compared with physiologic saline. The electrical resistance of the saline-filled epidural catheters significantly differed among products tested. We conclude that epidural catheterization that is guided by electrical stimulation should be performed only with catheters equipped with spiral stainless steel wire reinforcement or with a stainless steel stylet.

Anesthesia, Epidural↗

PubMed2005

Impact of the Japanese Diagnosis Procedure Combination-based Payment System on cardiovascular medicine-related costs.

In 2003, a lump-sum payment system based on Diagnosis Procedure Combinations (DPC) was introduced to 82 specific function hospitals in Japan. While the US DRG/PPS system is a "per case payment" system, the DPC based payment system adopts a "per day payment." It is generally believed that the Japanese system provides as much of an incentive as the DRG/PPS system to shorten the average length of stay (LOS). We performed an empirical analysis of the effect of LOS shortening on hospital revenue and expenditure under the DPC-based payment system, particularly in cardiovascular diseases. We also point out fundamentally controversial aspects of the current system. A total 109 cases were selected from patients hospitalized at the University of Tokyo Hospital from May to July, 2003 and classified into one of three categories: (1) cardiac catheter interventions, (2) cardiac catheter examinations, and (3) other conservative treatments. We analyzed the changes in profit per day in cases of a reduction in average LOS and an increase in the number of cases. In category (1) profit increased significantly in conjunction with reduced LOS. In category (2) profit increased only minimally. In category (3), profit increased rarely and sometimes decreased. In cases of conservative treatment, profits sometimes decreased because an increase in material costs exceeded the increase in revenue. It therefore became clear that the DPC-based payment system does not decisively provide an economic incentive to reduce LOS in cardiovascular medicine.

Cardiac Catheterization↗

PubMed2004

Mapping Japanese medical terms to UMLS Metathesaurus.

This paper introduces and reports the results for a project to map Japanese medical terms to the UMLS Metathesaurus. The "Thesaurus for Medical and Health related Terms version 5" published in 2003 by the Japan Medical Abstracts Society and UMLS version 2002AC provided by NLM were used in this study. The goal was to judge the validity of the correlation between the Japanese and English terms that belong to the same MeSH concept. Fifteen medicine, nursing, and library science professionals, excluding JAMAS, used a custom designed Web interface to perform this task. About 10% of the concepts were judged as invalid, and the reasoning behind these failures were analyzed. Experience from this project can be used to estimate the manpower required to revise the Japanese thesaurus after future revisions to UMLS or MeSH.

Internet↗

PubMed2003

Establishment of a method of anonymization of DNA samples in genetic research.

As the number of the genetic studies has rapidly increased in recent years, there has been growing concern that the privacy of the participants in such studies can be invaded unless effective measures are adopted to protect confidentiality. It is crucial for the scientific community to establish a method to anonymize DNA samples so that the public will trust genetic researchers. Here, we present a reliable and practical method of making DNA samples used in the genetic research anonymous. It assures complete anonymity by coding samples and personal information twice. Since it does not require equipment, such as bar-code readers or a software package, its cost is nominal compared with the laboratory costs. All institutions engaged in genetic research may wish to take measures such as the one described here to ensure the privacy and confidentiality of the participants in their genetic studies.

Anonymous Testing↗

PubMed2003

Information retrieval system for Japanese Standard Disease-code Master Using XML Web Service.

Information retrieval system of Japanese Standard Disease-Code Master Using XML Web Service is developed. XML Web Service is a new distributed processing system by standard internet technologies. With seamless remote method invocation of XML Web Service, users are able to get the latest disease code master information from their rich desktop applications or internet web sites, which refer to this service.

Disease↗

PubMed2002

Calcium channel blockers and myocardial infarction: a case--control study in a Japanese hospital.

PURPOSE: To examine the relationship of the use of calcium channel blockers (CCBs) in hypertensive patients to myocardial infarction in Japan, where CCBs are prescribed much more frequently than in Europe and America. DESIGN: We conducted a nested case-control study using a hospital information system in Japan. SUBJECTS: Cases were hypertensive patients who were repeat visitors to Tokyo University Hospital as of April 1996 and had an incidence of fatal or non-fatal myocardial infarction between 1996 and 1999. Controls were hypertensive patients individually matched to cases by sex, age and history of angina pectoris. RESULTS: The study consisted of 16 cases, who were matched to 80 controls. Of the 80 control patients, 54 (68%) received CCBs. On the other hand, all but one of 16 cases received CCBs and the crude odds ratio of myocardial infarction associated with the use of calcium channel blockers was as high as 7.0 (0.9-55.3). The odds ratio was reduced to 4.9 (0.6-42.4) when adjusted by diabetes and diastolic blood pressure. CONCLUSIONS: Although the crude odds ratio of myocardial infarction associated with CCBs was high, the ratio was reduced when adjusted by known confounding factors, suggesting a mechanism of confounding by indication. In addition, the results obtained in this study using records from a single hospital should not be generalized.

Aged↗

PubMed2002

Developing and integrating an adverse drug reaction reporting system with the hospital information system.

We have developed an adverse drug reaction (ADR) reporting system integrating it with Hospital Information System (HIS) of the University of Tokyo Hospital. Since this system is designed with JAVA, it is portable without re-compiling to any operating systems on which JAVA virtual machines work. In this system, we implemented an automatic data filling function using XML-based (extended Markup Language) files generated by HIS. This new specification would decrease the time needed for physicians and pharmacists to fill the spontaneous ADR reports. By clicking a button, the report is sent to the text database through Simple Mail Transfer Protocol (SMTP) electronic mails. The destination of the report mail can be changed arbitrarily by administrators, which adds this system more flexibility for practical operation. Although we tried our best to use the SGML-based (Standard Generalized Markup Language) ICH M2 guideline to follow the global standard of the case report, we eventually adopted XML as the output report format. This is because we found some problems in handling two bytes characters with ICH guideline and XML has a lot of useful features. According to our pilot survey conducted at the University of Tokyo Hospital, many physicians answered that our idea, integrating ADR reporting system to HIS, would increase the ADR reporting numbers.

Adverse Drug Reaction Reporting Systems↗

PubMed2002

[Case report summary browsing system for education of pharmaceutical students through the Internet].

We have developed a patient case database at Gunma University Hospital. The transmission of the data contained in this database via the Internet is protected by SSH encryption technology. The database may also function as an education tool for medical and pharmaceutical students who can access this system through the Internet using a special browser system that we have also developed. In a survey questionnaire relating to our system conducted among graduate students, most responded positively to its usefulness as an opportunity for exposure to actual clinical practice. Because this system can introduce students to realistic and daily practices at hospitals, it might have a great impact on Japanese pharmaceutical education in universities or pharmaceutical colleges where early exposure to actual hospital practices is not appropriately included in the curriculum. In addition, our system will function to establish a mutual feedback system between hospitals and basic research institutions such as pharmaceutical universities.

Case-Control Studies↗

PubMed2002

[The construction and evaluation of the preventing method for the input mischoice in a prescription order entry system--usefulness of a three-character input and a warning screen display system].

In the computerized prescription order entry system, it has been pointed out that a physician's input mischoice for medicine is one of the causes of medication errors. We therefore investigated the input mischoices by physicians at the time of writing prescriptions. Subsequently, the number of input characters in a prescription order was changed to three characters from two characters. Furthermore, 105 items of high-alert medications, which are likely to result in injury if errors occur, were established. A warning screen display system that requests reconfirmation of the effect, name, usage, and dosage of those medicines was also built. It was found that 70% of input mistakes were caused by choosing the medicine displayed immediately above or below the desired drug. By changing the number of input characters of a prescription order to three characters from two characters, the rate of specification of a trademark improved sharply from 36% to 85%. Consequently, the rate of choice of a drug with another trademark decreased significantly from 0.028% to 0.0047%. In 5% of cases when the warning screen was displayed for a high-alert medicine, the prescription was stopped, and 25% were changed to other medicines. The above results show that the system that requires the input of three or more characters for the physician order entry and displays a warning screen for high-alert medicines is useful in preventing mischoices at the time of prescription input.

Artificial Intelligence↗