Katsuhiko Ogasawara

Context-based ontology building support in clinical domains using formal concept analysis

OBJECTIVE Ontology in clinical domains is becoming a core research field in the realm of medical informatics. The objective of this study is to explore the potential role of formal concept analysis (FCA) in a context-based ontology building support in a clinical domain (e.g. cardiovascular medicine here). METHODOLOGY We developed an ontology building support system that integrated an FCA module with a natural language processing (NLP) module. The user interface of the system was developed as a Protégé-2000 JAVA tab plug-in. A collection of 368 textual discharge summaries and a standard dictionary of Japanese diagnostic terms (MEDIS ver2.0) were used as the main knowledge sources. A preliminary evaluation was taken to show the usefulness of the system. RESULTS Stability was shown on the MEDIS-based medical concept extraction with high precision. 73+/-14% (mean+/-S.D.) of the compound medical phrases extracted were sufficiently meaningful to form a medical concept from a clinical perspective. Also, 57.7% of attribute implication pairs (i.e. medical concept pairs) extracted were identified as positive from a clinical perspective. CONCLUSION Under the framework of our ontology building support system using FCA, the clinical experts could reach a mass of both linguistic information and context-based knowledge that was demonstrated as useful to support their ontology building tasks.

Forecasting the absolute and relative shortage of physicians in Japan using a system dynamics model approach

BackgroundIn Japan, a shortage of physicians, who serve a key role in healthcare provision, has been pointed out as a major medical issue. The healthcare workforce policy planner should consider future dynamic changes in physician numbers. The purpose of this study was to propose a physician supply forecasting methodology by applying system dynamics modeling to estimate future absolute and relative numbers of physicians.MethodWe constructed a forecasting model using a system dynamics approach. Forecasting the number of physician was performed for all clinical physician and OB/GYN specialists. Moreover, we conducted evaluation of sufficiency for the number of physicians and sensitivity analysis.Result & conclusionAs a result, it was forecast that the number of physicians would increase during 2008–2030 and the shortage would resolve at 2026 for all clinical physicians. However, the shortage would not resolve for the period covered. This suggests a need for measures for reconsidering the allocation system of new entry physicians to resolve maldistribution between medical departments, in addition, for increasing the overall number of clinical physicians.

An ontological approach to support the description of nursing practice in Japan with the ICNP.

BACKGROUND With increasing computerization of nursing records in Japan, standardization of nursing terminology is becoming imperative. Although some efforts have been made to formalize description of nursing practice in Japan with the International Classification of Nursing Practice (ICNP), lack of effective description tools has impacted negatively on the initiatives. PURPOSE To develop and evaluate an ontological approach that could be used to facilitate the description of nursing practice in Japan with the ICNP. METHODOLOGY An ontology-based support system was developed using Protégé-2000, mainly by the following three steps: (1) representing a standard classification of nursing practice (the Nursing Master) in Japan; (2) representing a Japanese version of the ICNP; (3) designing an ontology-based framework. A heuristic matching algorithm was developed to automatically match the action labels in the Nursing Master with the terms of the eight axes of the ICNP Nursing Actions Classification. A preliminary evaluation was performed to examine the usefulness of the system. RESULTS High hit rate was shown on the ICNP axes ActionType, Target, and Location. The evaluation indicated that 51.7+/-5.8% (mean+/-S.D.) of the action labels with only one action type were properly matched, and that in 80+/-4% (mean+/-S.D.) of action labels with more than one action type, at least one valid action type was matched correctly. CONCLUSION The ontology-based approach using a frame-based knowledge representation system (e.g., Protégé-2000) is useful for supporting the formal description of nursing practice in Japan with the ICNP.

Problem-based learning for radiological technologists: a comparison of student attitudes toward plain radiography

BackgroundKnowledge and skill expected of healthcare providers continues to increase alongside developments in medicine and healthcare. Problem-based learning (PBL) is therefore increasingly necessary in training courses for radiological technologists. However, it is necessary to evaluate the effects of PBL to completely introduce it in our education programs. As a Hypothesis, it seems that a change occurs in the student’s attitudes by participating in PBL practical training. There is the Semantic Differential (SeD) technique as a method to identify student’s attitudes. We conceived that PBL could be appropriately evaluated by using SeD technique. In this paper, we evaluated PBL for plain radiography practical training using the SeD technique.MethodsThirty-eight third-year students studying radiological technology participated. PBL was introduced to practical training in plain radiography positioning techniques. Five sessions lasting 5 h each were delivered over a 5-week period during November to December 2012. The clinical scenario was an emergency case with multiple trauma requiring plain radiography. Groups comprising approximately eight students created workflows for trauma radiography with consideration of diagnostic accuracy and patient safety. Furthermore, students groups conducted plain radiography on a patient phantom according to created workflows and were then guided by feedback from professional radiologists. All students answered SeD questionnaires to assess views on plain radiography before instruction to provide preliminary practical training reports and after completing practical training.ResultsThe factors were identified using factor analysis of the questionnaires, which were answered before and after each practical training session. On evaluation of the relationships between factors and question items according to factor loading, we identified “reluctance”, “confidence”, and “exhaustion” as the predominant attitudes before practical training. Similarly, we identified “expectation”, “self-efficacy”, and “realness” as the predominant attitudes after practical training. The attitudes toward plain radiography changed before and after PBL practical training.ConclusionsThe attitude of self-efficacy was noted after practical training, which incorporated PBL. Student self-efficacy was thought to increase through self-directed learning, which is one of the aims of PBL. Although the influences of other lectures and training, which were performed in parallel with the PBL practice training, were not completely excluded, and although the number of study participants was small, we were able to confirm the effects of PBL.

The Prognostic Value of Normal Stress Cardiovascular Magnetic Resonance Imaging

Objectives The purpose of our study was to determine the prognostic value of normal stress cardiovascular magnetic resonance imaging (CMR) by a systematic literature review and meta-analysis. Methods A comprehensive literature search of published studies through November 2011 in MEDLINE database and Cochrane Library, regarding prognostic value of stress CMR in patients with known or suspected coronary artery disease, was performed. Results Ultimately, we identified 11 studies. The summary relative risk ratio for major adverse cardiac events was 0.50 (95% confidence interval [CI], 0.44–0.58) for normal cine CMR and 0.09 (95% CI, 0.02–0.35) for normal perfusion CMR. The summary relative risk ratio for hard cardiac events was 0.36 (95% CI, 0.16–0.8) for normal cine CMR and 0.22 (95% CI, 0.07–0.66) for normal perfusion CMR. Conclusions Normal stress CMR for patients known or suspected of having coronary artery disease has good prognostic value in predicting cardiac events.

Quantitative analysis of ontology research articles in the radiologic domain

To investigate the most advanced ontology research in health care and its impact on the radiologic domain, we proposed a concept identification and abstraction technique called “Concept Step”. This technique identifies a MeSH term, medical subject headings used in PubMed, in a sentence and climbs up through its hierarchy to reach an abstract concept. We developed original Java software to implement this technique. We tested it on 2,774 abstracts in health-care ontology research retrieved from MEDLINE on 23 October 2008. The total number of MeSH terms was 112,690. We counted a total of 33 MeSH terms (0.029%) in the radiologic domain. The most frequently occurring term was “radiology”, which occurred 21 times in the article set. Other frequent terms were “magnetic resonance imaging” and “tomography”, the counts of which were 4 and 3, respectively. A pair plot showed no correlation among the MeSH categories “Analytical Diagnostic and Therapeutic Techniques and Equipment”, “Anatomy”, “Biological Sciences”, and “Chemicals and Drugs”. We conclude that ontology research is well established in the biomedical domain, and that further study is required in the radiologic domain.

Nutritional Status and Body Composition of Independently Living Older Adults in a Snowy Region of Japan

Lifestyle diseases, which are associated with nutrition, account for 30% of elderly requiring long-term care. To increase health expectancy among Japan’s rapidly aging population, we investigated the nutritional status and body composition of elderly adults living in a region subject to heavy snowfall, to identify pertinent health indicators. The dietary habits of 288 local residents aged ≥50 years were analyzed using body composition and a brief-type self-administered diet history questionnaire. Body mass index of all residents was normal. Basal metabolic rate (BMR) and muscle mass were reduced in the older group. Dietary habits did not differ with age among men, but older women had significantly higher dietary intake. BMR and muscle mass declined with age, even when dietary intake was sustained. Despite sufficient dietary intake, independently living older adults demonstrate less efficient use of food with age. Interventions to reduce excessive sodium and protein intake are required.

Development and current status of an advanced telehealth consultation system in Japan

In recent years, many changes have occurred in the social and medical environments in Japan because of a rapidly aging population and declining birthrates. A shortage of physicians is one of the most critical medical issues, and the current number of physicians per unit of population is lower than the average value reported by the Organization for Economic Cooperation and Development in 2012. The shortage of physicians and increasingly limited access to medical care in Japan is a cause of concern for much of the population, particularly the elderly population. To address this situation, we developed an advanced telehealth consultation system in Hokkaido, the northernmost and second largest island in Japan. The shortage of physicians in Hokkaido prefecture is compounded by regional gaps in healthcare and medical services between rural and urban areas. The prefectural government of Hokkaido is located in Sapporo City, where 35% of the population lives and where 36% of hospitals are located. People living outside urban areas are required to spend more time and money for consulting healthcare professionals, in particular hospital-based professionals. Many countries have now established telehealth consultation systems. However, there are few teleconsultation systems in Japan. In an attempt to minimize the disparity in healthcare resources between rural areas and urban areas, we proposed a telehealth consultation system based on secure, high-speed internet and high-definition television located in local pharmacies. On the basis of the findings of a 2012 study on team-based medical care, including pharmacy-based and community-based healthcare, the Ministry of Health, Labor and Welfare of Japan identified a role for pharmacies as hubs for health information. Expanding a pharmacy-based healthcare system, which provides products and services on a daily basis, will enable appropriate self-medication and improved health monitoring. In this report, we describe our implementation of our new Japanese pharmacy-based telehealth consultation system and present the results of a study assessing the usage and impact of the system. Methods

Development of terminology for mammographic techniques for radiological technologists

We are developing a mammographic ontology to share knowledge of the mammographic domain for radiologic technologists, with the aim of improving mammographic techniques. As a first step in constructing the ontology, we used mammography reference books to establish mammographic terminology for identifying currently available knowledge. This study proceeded in three steps: (1) determination of the domain and scope of the terminology, (2) lexical extraction, and (3) construction of hierarchical structures. We extracted terms mainly from three reference books and constructed the hierarchical structures manually. We compared features of the terms extracted from the three reference books. We constructed a terminology consisting of 440 subclasses grouped into 19 top-level classes: anatomic entity, image quality factor, findings, material, risk, breast, histological classification of breast tumors, role, foreign body, mammographic technique, physics, purpose of mammography examination, explanation of mammography examination, image development, abbreviation, quality control, equipment, interpretation, and evaluation of clinical imaging. The number of terms that occurred in the subclasses varied depending on which reference book was used. We developed a terminology of mammographic techniques for radiologic technologists consisting of 440 terms.

Factors Affecting Bone Mineral Density Among Snowy Region Residents in Japan: Analysis Using Multiple Linear Regression and Bayesian Network Model

Background As the onset of osteoporosis leads to reduced activities of daily living and may result in patients being bedridden, efforts to prevent decreased bone density are necessary. Various studies on the relationship between sex, age, nutrients, and exercise habits and bone mineral density have been conducted to date. However, for snowy region residents, the magnitude of influence of various factors affecting bone mineral density and the influence level have not been clarified. Objective This study aimed to clarify the degree of influence and factors influencing bone mineral density based on survey results on health conditions and lifestyle habits in heavy snow areas. Methods A total of 354 citizens who visited a drugstore in the target area were included in a study that included using the brief-type self-administered diet history questionnaire on lifestyle and exercise habits. Height, weight, body composition, and bone densitometer values were analyzed using multiple regression to calculate their association with bone mineral density. In addition, a Bayesian network model was used to determine the influence level of each factor as a conditional probability. Results Multiple regression analysis revealed that age, sex, fracture, and calcium intake significantly influenced bone mineral density. In addition, the result of Bayesian network analysis suggested that age and sex affected bone mineral density, whereas nutrients and exercise habits might not have a direct impact. However, calcium intake and the T-score were significant factors affecting the presence or absence of fracture experiences, suggesting that adequate calcium intake is essential for preventing fractures. Conclusions In the multiple regression analysis, age, sex, fracture, and calcium intake were selected as factors; however, in the Bayesian analysis, only age and sex affected bone mineral density while nutrients did not. In addition, the fact that calcium intake and the T-score were shown to affect bone fracture history suggests that calcium intake is an important measure that can prevent bone fractures. Overall, these results suggest that measures such as ensuring a bone fracture–free environment and providing nutritional advice for calcium intake can be effective in preventing bone loss.