A unifying hypothesis to explain the retardation of aging and tumorigenesis by caloric restriction.
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Aging↗
Biomedical subjects
H R Warner
Publications and source records attributed to H R Warner.
Interfacing a stand-alone diagnostic expert system with a hospital information system.
Few diagnostic decision-support systems are in routine clinical use, mainly because these systems typically require time-consuming manual data entry. This research investigated the feasibility of reducing manual data entry by integrating a stand-alone diagnostic expert system with an existing comprehensive hospital information system (HIS). A knowledge-based intervocabulary mapping technique was developed to map disparate vocabularies. The results of a retrospective study indicate that transferring clinical data from the HIS to the diagnostic expert system at the beginning of workup significantly reduces the manual data entry required for generating the correct diagnoses for patients.
Diagnosis, Computer-Assisted↗
Decision support in medicine: examples from the HELP system.
Computerized health information systems can contribute to the care received by patients in a number of ways. Not the least of these is through interactions with health care providers to modify diagnostic and therapeutic decisions. Since its beginning, developers have used the HELP hospital information system to explore computerized interventions into the medical decision making process. By their nature these interventions imply a computer-directed interaction with the physicians, nurses, and therapists involved in delivering care. In this paper we describe four different approaches to this intervention. These include: (1) processes that respond to the appearance of certain types of clinical data by issuing an alert informing caregivers of these data's presence and import, (2) programs that critique new orders and propose changes in those orders when appropriate, (3) programs that suggest new orders and procedures in response to patient data suggesting their need, and (4) applications that function by summarizing patient care data and that attempt to retrospectively assess the average or typical quality of medical decisions and therapeutic interventions made by health care providers. These approaches are illustrated with experience from the HELP system.
Adult↗
Designing a controlled medical vocabulary server: the VOSER project.
The authors describe their experience designing a controlled medical vocabulary server created to support the exchange of patient data and medical decision logic. The first section introduces practical and theoretical premises that guided the design of the vocabulary server. The second section describes a series of structures needed to implement the proposed server, emphasizing their conformance to the design premises. The third section introduces potential applications that provide services to end users and also a group of tools necessary for maintaining the server corpus. In the fourth section, the authors propose an implementation strategy based on a common framework and on the participation of groups from different health-related domains.
Clinical Laboratory Information Systems↗
Superoxide dismutase, aging, and degenerative disease.
Over 15 years of research on correlations between superoxide dismutase (SOD) activity and aging or life span have failed to provide a consistent picture of the role of SOD in aging. While genetic manipulations that increase CuZn-SOD activity have only a slight, if any, effect on maximum life span in several species, they do increase resistance to oxidative stress. However, increasing both CuZn-SOD and catalase does significantly increase maximum life span. Decreased SOD expression in a variety of species increases their vulnerability to oxidative stress, and in the case of genetically altered CuZn-SOD, leads to premature death of motor neurons in humans. Little is known about the regulation of expression of SOD and other antioxidant defense enzymes in eukaryotes. The research summarized below collectively suggest that SOD plays an important role in longevity and degenerative disease, but much remains to be learned before manipulation of SOD expression can be considered for effective intervention in either process.
Aging↗
Superoxide dismutase, oxygen radical metabolism, and amyotrophic lateral sclerosis.
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Amino Acid Sequence↗
Automated transformation of probabilistic knowledge for a medical diagnostic system.
Iliad is a large medical diagnostic system that covers more than 2000 diagnoses and 9000 findings. Due to the size and the complexity of this system, a robust knowledge representation is essential to consistently and efficiently model the medical knowledge involved. In this paper, we describe the knowledge representation currently used in Iliad and a probabilistic representation based on the Bayesian network formalism which can be derived using the information that the Iliad knowledge base contains.
Algorithms↗
Development and implementation of a computer-generated reminder system for diabetes preventive care.
Diabetes mellitus is a chronic condition with several late complications that can be delayed or avoided through proper preventive health care. Although practice guidelines have been established to improve the preventive care in diabetics, dissemination of these guidelines among physicians and educational programs have been only moderately successful in changing physicians' practice patterns. Previous efforts, however, did not utilize computer-generated reminders. We developed a system of computer-generated reminders for diabetic preventive care. We completed an implementation of the system in the outpatient clinics of internal medicine residents at our institution. This paper describes the development and implementation of this system. Our results showed that the system flagged an average of 13 items that deviated from diabetes guideline compliance, out of a possible 21 items per patient. The residents completed encounter forms used by the system for 37% of patients seen during a six month period. Physician users exhibited positive attitudes toward the use of guidelines which they judged improved quality at no additional cost of care. However, the complexity and length of the guideline encounter forms and the additional time demands proved to be significant obstacles to current routine use. Our experience will help to improve the system so that it is more usable and acceptable to physicians, especially in the future as health care increasingly makes use of electronic medical record systems.
Attitude to Computers↗
Graduate program in medical informatics at the University of Utah.
The graduate student program in medical informatics at the University of Utah described in this paper comprises a Master of Science degree (since 1976) and a Ph.D. degree (since 1962). The average program length is 2 years for M.Sc. and 3-5 years for Ph.D. The aims of the program are to prepare graduates for careers in medical informatics in academic, hospital or industrial settings. There are several different courses of study, or tracks, within the department ranging from Expert Systems, Genetic Epidemiology, Health Care Quality, Hospital Information Systems, Medical Imaging, Medical Physics, to an intensive one-year M.Sc. degree course for physicians. After the first three quarters the students are required to take a qualifying examination in which they qualify for a Masters or Ph.D. degree. The program covers the total spectrum of medical informatics. About 10 students are admitted each year. There are 14 full-time faculty and 9 adjunct faculty. The total number of graduates is 151.
Curriculum↗
Performance of a diagnostic system (Iliad) as a tool for quality assurance.
Quality assurance improves health care through detection of quality problems and feedback to the care giver. Current review procedures employed by the Peer Review Organizations (PROs), however, appear to underdetect quality problems, particularly those arising from diagnostic errors. We studied the use of an expert diagnostic system, Iliad, to detect quality problems arising from diagnostic errors. One hundred cases were selected from among those Medicare cases reviewed by the Utah PRO (UPRO) and which contained diagnoses recognized by Iliad. Iliad flagged 28 cases out of the 100 as containing diagnostic errors, and a gold standard physician review confirmed quality problems in 17 cases (60.7%). The UPRO review found 28 cases with quality problems, mostly treatment and documentation errors. The quality problems detected by Iliad appeared to be more serious than those detected by the UPRO review. Among the six cases with quality problems detected by both the UPRO and the Iliad review, there was none for which the same quality problem was detected by the two procedures. The two review procedures were therefore complementary.
Adult↗
Control of cell proliferation in senescent cells.
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Animals↗
Iliad's role in the generalization of learning across a medical domain.
Medical informatics could facilitate more effective analysis and use of clinical knowledge by means of expert systems. To be most effective, such systems should be constructed in a manner which is consistent with physicians' cognitive processes. Our past five years' work with a system called Iliad indicates that it provides effective medical training and education. The current research extends our previous work by using a wider array of training and test cases. We also evaluated whether training on specific cases could generalize to improved testing performance on related cases, which featured similar complaints and pathophysiologic mechanisms, but different final diagnoses. In their junior internal medicine clerkship, students (n = 100) completed 1300 Iliad training cases covering 48 diagnoses. The findings indicated improved problem solving on the specifically trained cases as well as the generalization cases. We discuss a possible training model for expert systems such as Iliad.
Computer-Assisted Instruction↗
Comparison of different information content models by using two strategies: development of the best information algorithm for Iliad.
Iliad is a diagnostic expert system for internal medicine. Iliad's "best information" mode is used to determine the most cost-effective findings to pursue next at any stage of a work-up. The "best information" algorithm combines an information content calculation together with a cost factor. The calculations then provide a rank-ordering of the alternative patient findings according to cost-effectiveness. The authors evaluated five information content models under two different strategies. The first, the single-frame strategy, considers findings only within the context of each individual disease frame. The second, the across-frame strategy, considers the information that a single finding could provide across several diseases. The study found that (1) a version of Shannon's information model performed the best under both strategies---this finding confirms the result of a previous independent study, (2) the across-frame strategy was preferred over the single-frame strategy.
Algorithms↗
Iliad training enhances medical students' diagnostic skills.
Iliad is a computerized, expert system for internal medical diagnosis. The system is designed to teach diagnostic skills by means of simulated patient case presentations. We report the results of a controlled trial in which junior students were randomly assigned to received Iliad training on one of two different simulated case mixes. Each group was subsequently tested in both their "trained" and "untrained" case domain. The testing consisted of computerized, simulated patient cases for which no training feedback was provided. Outcome variables were designed to measure the students' performance on these test cases. The results indicate that students made fewer diagnostic errors and more conclusively confirmed their diagnostic hypotheses when they were tested in their trained domain. We conclude that expert systems such as Iliad can effectively teach diagnostic skills by supplementing trainees' actual case experience with computerized simulations.
Clinical Clerkship↗
An interlingua for electronic interchange of medical information: using frames to map between clinical vocabularies.
The proliferation of medical knowledge has led to the development of extensive dictionaries for electronically accessing information resources. The task of standardizing terminology used for electronic hospital records and for knowledge bases for medical expert systems and indexing the medical literature cannot easily be met by developing a single, monolithic "official" medical vocabulary. Developing a monolithic vocabulary would require a massive effort, and its existence would not guarantee its use by third-party payors, by practicing clinicians, or by developers of electronic medical information systems. Recognizing this, the National Library of Medicine (NLM) has begun to develop the Unified Medical Language System (UMLS) as a means of promoting electronic information exchange among systems with controlled vocabularies. The authors describe a frame-based system developed as an experimental approach to mapping between controlled clinical vocabularies.
Cluster Analysis↗
Performance of a diagnostic system (Iliad) as a tool for quality assurance.
Quality Assurance improves health care through detection of quality problems and feedback to the care giver. Current review procedures employed by the Peer Review Organizations (PROs), however, appear to under-detect quality problems, particularly those arising from diagnostic errors. We studied the use of an expert diagnostic system, Iliad, to detect quality problems arising from diagnostic errors. 100 cases were selected from among those Medicare cases reviewed by the Utah PRO (UPRO) and which contained diagnoses recognized by Iliad. Iliad flagged 28 cases out of the 100 as containing diagnostic errors, and a gold standard physician review confirmed quality problems in 17 cases (60.7%). The UPRO review found 28 cases with quality problems, mostly treatment and documentation errors. The quality problems detected by Iliad appeared to be more serious than those detected by the UPRO review. Among the six cases with quality problems detected by both the UPRO and Iliad review, there was none for which the same quality problem was detected by the two procedures. The two review procedures were therefore complementary.
Diagnosis, Computer-Assisted↗
Performance of a diagnostic system (Iliad) as a tool for quality assurance.
Quality Assurance improves health care through detection of quality problems and feedback to the care giver. Current review procedures employed by the Peer Review Organizations (PROs), however, appear to underdetect quality problems, particularly those arising from diagnostic errors. We studied the use of an expert diagnostic system, Iliad, to detect quality problems arising from diagnostic errors. 100 cases were selected from among those Medicare cases reviewed by the Utah PRO (UPRO) and which contained diagnoses recognized by Iliad. Iliad flagged 28 cases out of the 100 as containing diagnostic errors, and a gold standard physician review confirmed quality problems in 17 cases (60.7%). The UPRO review found 28 cases with quality problems, mostly treatment and documentation errors. The quality problems detected by Iliad appeared to be more serious than those detected by the UPRO review. Among the six cases with quality problems detected by both the UPRO and Iliad review, there was none for which the same quality problem was detected by the two procedures. The two review procedures were therefore complementary.
Diagnosis, Computer-Assisted↗
Exploring a new best information algorithm for Iliad.
Iliad is a diagnostic expert system for internal medicine. One important feature that Iliad offers is the ability to analyze a particular patient case and to determine the most cost-effective method for pursuing the work-up. Iliad's current "best information" algorithm has not been previously validated and compared to other potential algorithms. Therefore, this paper presents a comparison of four new algorithms to the current algorithm. The basis for this comparison was eighteen "vignette" cases derived from real patient cases from the University of Utah Medical Center. The results indicated that the current algorithm can be significantly improved. More promising algorithms are suggested for future investigation.
Algorithms↗