Search PubMed⌕ Search

Biomedical subjects

C G Chute

Publications and source records attributed to C G Chute.

At least 37 records · Page 2Linked to original sources
PubMed1998

Scalable methodologies for distributed development of logic-based convergent medical terminology.

As the size and complexity of medical terminologies increase, terminology modelers are increasingly hampered by lack of tools and methods to manage the development process. This paper presents our use and ongoing evaluation of a description-logic classifier to support cognitive scalability of the underlying terminology and our enhancements to that classifier to support concurrent development utilizing semantics-based concurrency control methods. Our enhancements, collectively referred to as the Gálapagos, consist of several applications that take locally-developed terminology enhancements from multiple sites, identify conflicting design decisions, support the modelers' reconciliation of the conflicting designs, and efficiently disseminate updates tailored for locally enhanced terminologies. We have tested our ideas through concurrent evolutionary enhancement of SNOMED International at three Kaiser Permanente regions and the Mayo Clinic. We have found that the underlying environment has met our design objectives, and supports semantic-based concurrency control, and identification and resolution of conflicting design decisions.

Artificial Intelligence↗
PubMed1998

The Copernican era of healthcare terminology: a re-centering of health information systems.

Health terminology and classifications have been an unseen backwater in healthcare practice and information systems development. Today however, the recognized need for comparable patient data is driving a new discovery about its strategic importance. Consistent patient descriptions and concept-centered data representations are crucial for efficient discovery of optimal treatments, best outcomes, and efficient practice patterns. The fabled linkage of knowledge sources at the time and place of care requires the conceptual intermediary of common terminology. A brief history overviewing the evolution of health classifications will provide the foundation for considering present and evolving health terminology developments. Their roles in health information systems will be characterized. Discussion will focus on the likely influences of the HIPAA legislation nationally and the new ISO Healthcare Informatics Technical Committee internationally, on terminology adaptation and incorporation.

Disease↗
PubMed1998

A randomized controlled trial of automated term composition.

OBJECTIVE: To compare the ability of an Automated Term Composition (ATC) algorithm with non-compositional mappings to provide coverage (exact mappings to a controlled vocabulary) for a randomly selected set of free text entries which were entered as headings to the Impression section of the clinical notes system at the Mayo Foundation. We also compare the results of four evaluators to determine the inter-observer variability and the variance between term sets, with respect to the accuracy of the mappings and the reliability of the failure analysis. METHODS: From a corpus of approximately 1,000,000 unique terms entered into the Impression/Report/Plan section of the clinical notes system in the calendar year 1997, we randomly selected 1,000 terms. We then further randomized these 1,000 terms into two groups of 500 (Sets A and B). We constructed two copies of the same term matching interface, one without ATC (alpha) and one with ATC (beta). We took four expert Indexers and assigned them to one of the following tasks. The first reviewer (R1) compared set A using the alpha program and then set B using the beta program (R1(Aalpha + Bbeta)). The second compared set A using the alpha program and then set B using the alpha program (R2(A + B) alpha). The third compared set B using the beta program and then set A using the beta program (R3(B + A) beta). The fourth compared set A using the beta program and then set B using the alpha program (R4(Abeta + Balpha)). RESULTS: The program with Automated Term Composition mapped 540 out of the 1,000 Concepts correctly (54.0%). The same program without ATC mapped only 276 out of the 1,000 Concepts correctly (27.6%). Therefore the program with ATC was significantly more effective at matching concepts in our problem lists than the same search engine without ATC (p < 0.0001; McNemar Method). These figures result from the comparison of the alpha program with the beta program by reviewers one and four. Failure analysis showed that with the alpha version 425 out of the 724 mismatches were because a base concept was missing from the retrieval set (58.7%) and 299 mismatches were from missing qualifiers or modifiers or both (41.3%). In the beta version of the program (with ATC) 340 out of the 460 mismatches were secondary to there being a missing base concept in the retrieval set (73.9%) and only 120 mismatches due to missing modifiers and or qualifiers (26.1%). CONCLUSIONS: Automated term composition provided significantly better coverage of a randomly chosen set of patient problems, diagnosed at the Mayo Clinic during the 1997 calendar year, when compared with the same information retrieval system without ATC. We believe that these results speak further to the excellent content coverage provided by the UMLS metathesaurus. These authors believe that increased structure, normalization of UMLS content and semantics, and better tools to make use of the currently available content such as automated term composition, are what is needed to leverage the production of commercially viable tools that provide access to controlled vocabularies for medicine.

Abstracting and Indexing↗
PubMed1998

A clinical terminology in the post modern era: pragmatic problem list development.

A brief review of the rich heritage of classifications and terminologies is the background for a description of the Mayo Clinic's clinical terminology development. Vender specific system constraints prompted the scope and style of an interim problem list vocabulary. We describe the sources and review process which led to a working terminology for use in a Computer-based Patient Record (CPR). Because terminology development is often subjective and metrics against which to measure the quality of individual human judgements are few, we decided to compare the selection of preferred terms made by general internists with those made by sub-specialists. A significant difference between a sub-specialist's assignment of preferred terms and a general internist's (948 vs. 2271, P < 0.001) was observed. Sub-specialists were less than half as likely as a generalist to designate a term as a preferred form. These results emphasize the need for sub-specialty editing when assigning preferred terms to concepts.

Disease↗
PubMed1997

Clinical care management and workflow by episodes.

This paper describes the implementation of clinically defined episodes of care and the introduction of an episode-based summary list of patient problems across Mayo Clinic Rochester in 1996 and 1997. Although Mayo's traditional paper-based system has always relied on a type of 'episode of care' (called the "registration") for patient and history management, a new, more clinically relevant definition of episode of care was put into practice in November 1996. This was done to improve care management and operational processes and to provide a basic construct for the electronic medical record. Also since November 1996, a computer-generated summary list of patient problems, the "Master Sheet Summary Report," organized by episode, has been placed in all patient histories. In the third quarter of 1997, the ability to view the episode-based problem summary online was made available to the 3000+ EMR-capable workstations deployed across the Mayo Rochester campus. In addition, the clinically oriented problem summarization process produces an improved basic "package" of clinical information expected to lead to improved analytic decision support, outcomes analysis and epidemiological research.

Episode of Care↗
PubMed1997

Standardized problem list generation, utilizing the Mayo canonical vocabulary embedded within the Unified Medical Language System.

UNLABELLED: VOCABULARY: The Mayo problem list vocabulary is a clinically derived lexicon created from the entries made to the Mayo Clinic's Master Sheet Index and the problem list entries made to the Impression/ Report/Plan section of the Clinical Notes System over the last three years. The vocabulary was reduced by eliminating repetition including lexical variants, spelling errors, and qualifiers (Administrative or Operational terms). Qualifiers are re-coordinated with other terms, at run-time, which greatly increased the number of input strings which our system is capable of recognizing. IMPLEMENTATION: The Problem Manager is implemented using standard windows tools in a Windows NT environment. The interface is designed using Object Pascal. HTTP calls are passed over the World Wide Web to a UNIX based vocabulary server. The server returns a document, which is read into Object Pascal structures, parsed, filtered and displayed. STUDY: This paper reports the results of a recent Usability Trial focused on assessing the viability of this mechanism for standardized problem entry. Eight clinicians engaged in eleven scenarios and responded as to their satisfaction with the systems performance. These responses were observed, videotaped and tabulated. Clinicians in this study were able to find acceptable diagnoses in 91.1% of the scenarios. The response time was acceptable in 92.5% of the scenarios. The presentation of related terms was stated to be useful in at least one scenario by seven of the eight participants. All clinicians wanted to make use of shortcuts which would minimize the amount of typing necessary to encode the concept they were searching for (e.g. Abbreviations, Word Completion). CONCLUSIONS: Clinicians are willing to choose a canonical term from a suggested list (as opposed to their own wording). Clinicians want an "intelligent" system, which would suggest terms within a category (e.g. Types of "Migraine"). They are able to make functional use of our system, in its current state of development. Finally, all clinicians appreciate the value of encoding their problems in a standardized vocabulary, toward improved research, education and practice.

Computer Communication Networks↗
PubMed1997

A clinically derived terminology: qualification to reduction.

Mayo Foundation is developing synonym rich entry points for the recording of patient problems by clinicians, which will map to the KP-Mayo Convergent Medical Terminology. We describe the empirical sources for these terminology components, and how the number and complexity of the terms could be substantially reduced by the introduction of a Qualifier axis. The expressive power of these entry points is dramatically enhanced by this axis. This work is being integrated into terminology navigation modules being jointly developed with Lexical Technology, which leverages UMLS content. It will from the basis for structured problem entry into Mayo's Computer-based Electronic Record.

Clinical Medicine↗
PubMed1996

Gálapagos: computer-based support for evolution of a convergent medical terminology.

Current controlled medical terminologies fall short of the needs of informatics application developers. To overcome the limitations of current medical terminologies, many groups are independently enhancing existing terminologies to meet their local needs. With proper computer-based support, local enhancements can be used as evolutionary stepping stones toward a convergent medical terminology. Gálapagos is a collection of applications that can take local enhancements from multiple sites, identify conflicting design decisions, allow developers to reconcile the conflicting designs, and efficiently disseminate updates tailored specifically for compatibility with locally enhanced terminologies. This paper describes an initial proof-of-concept of the Gálapagos programs using data generated during concurrent SNOMED enhancement by Kaiser Permanente and the Mayo Clinic.

Medical Informatics Computing↗
PubMed1995

Incidence of prostate cancer diagnosis in the eras before and after serum prostate-specific antigen testing.

OBJECTIVE: To estimate the incidence of prostate cancer in Olmsted County, Minnesota, from 1983 through 1992 to describe the secular changes that have occurred since the introduction of serum prostate-specific antigen (PSA) testing to the community medical practice in 1987. DESIGN: Population-based, descriptive epidemiological study with ecological and individual level comparisons over time. STUDY SETTING: Olmsted County, Minnesota, where the Rochester Epidemiology Project provides passive surveillance of the population for health outcomes. SUBJECTS: All 511 biopsy-proven incident cases of adenocarcinoma of the prostate diagnosed from 1983 through 1992. The community inpatient and outpatient medical records of all incident cases were reviewed to evaluate the presenting characteristics of men at the time of diagnosis. RESULTS: The age-adjusted incidence of biopsy-proven prostate cancer increased from 64 per 100,000 person-years in 1983 to 216 per 100,000 person-years in 1992. The increase occurred primarily between 1987 and 1988 and was predominately for organ-confined tumors. The age-specific incidence increased dramatically in this same period among men aged 50 years and older. Among men aged 70 years and older, however, prostate carcinoma incidence rates declined after 1990 following the initial increase. This decline among older men contrasted with community-based estimates of PSA utilization rates, which demonstrated consistent increases since 1987 to nearly 50% of the older population in 1992. CONCLUSION: These results support the premise that the recent increase in prostate cancer is due in part to the increased utilization of serum PSA testing. Further, the increased incidence appears to be a transient phenomenon due to the depletion of previously undiagnosed cases from the previous pool. Finally, these data suggest that, in terms of stage at diagnosis, early detection efforts may be effective in identifying more early stage (smaller) cancers.

Adenocarcinoma↗
PubMed1995

Association between family history of benign prostatic hyperplasia and urinary symptoms: results of a population-based study.

Baseline measurements for a population-based prospective cohort study were used to assess the association between family history of enlarged prostate and urinary symptoms. Between December 1989 and March 1991, a group of randomly selected men aged 40-79 years from Olmsted County, Minnesota, was administered a previously validated questionnaire that included questions with wording close to that of the American Urological Association's Symptom Index. A detailed family history of an enlarged prostate was obtained by personal interview, and peak urinary flow rates were measured for each participant. Of the 2,119 men, 440 (21 percent) reported a family history of an enlarged prostate. The age-adjusted odds of having moderate or severe urinary symptoms were elevated among those with a family history relative to those without (odds ratio = 1.3, 95 percent confidence interval 1.1-1.7). With simultaneous control for effects of age and worry about urologic function, the odds ratio remained at 1.3 (95 percent confidence interval 1.0-1.6). Furthermore, this risk was greater for men with relatives diagnosed at a younger age (odds ratio = 2.5, 95 percent confidence interval 1.5-4.3). Men with a family history were also 1.3 times as likely to have an impaired peak urinary flow rate. These findings suggest that men with a family history of an enlarged prostate may be at increased risk for development of symptoms and signs suggestive of benign prostatic hyperplasia and that this risk is greater in men with relatives diagnosed at a younger age. Recognition of this association may help to target early interventions and may lead to further clues about the causes of benign prostatic hyperplasia.

Adult↗
PubMed1995

Exploration and exploitation of clinical databases.

Clinical data repositories represent a potential gold mine of information and knowledge. Rapid access to such information can help bridge the gap between clinical care and research, support clinical and executive decision making, and improve the quality of care. A clinical database can be used in four ways: to display information about an individual patient (results reporting); to find data on a patient with similarities to one being seen (case finding); to describe a group of patients with at least one attribute in common (cohort description); and to analyze data patterns in terms of trends or relationships (predictive modeling). It seems unlikely that many important clinical questions will be subject to randomized clinical trials because of the ethics, logistics, and expense that would be involved. Evolving statistical and epidemiological methods allow us to approach these clinical data repositories with the purpose of building predictive models, but a clear understanding of the limitations of routinely collected clinical data and the inherent biases is necessary. The largest barrier to using routinely collected clinical data is not the limitations of the data themselves, but rather the lack of a data paradigm for the decision-maker. We present some of the problems and pitfalls in obtaining and using routinely collected data, based upon the use of ClinQuery at Boston's Beth Israel Hospital and the resources and traditions at the Mayo Clinic.

Databases, Factual↗
PubMed1995

Natural history of prostatism: relationship among symptoms, prostate volume and peak urinary flow rate.

We describe relationships among symptoms, prostate volume and peak urinary flow rate in an age stratified, community based random sample of white men 40 to 79 years old with no prior prostate surgery, prostate cancer or other conditions known to interfere with voiding. Symptoms were assessed with an instrument comparable to the American Urological Association symptom index. Prostate volume was estimated by transrectal ultrasonography and peak urinary flow rate was measured by a portable device. Subject age was significantly associated with symptom score but accounted for only 3% of its variation, while prostate volume and peak urinary flow rate explained only an additional 10% of the symptom variability. The odds (95% confidence interval) of moderate to severe symptoms increased with age from 1.9 (1.1 to 3.1), 2.9 (1.7 to 5.0) and 3.4 (1.8 to 6.1) for men 50 to 59, 60 to 69 and 70 to 79 years old, respectively, relative to men 40 to 49 years old. Adjusting for age, the odds of moderate to severe symptoms were 3.5 times greater for men with prostatic enlargement (more than 50 ml.) than for men with smaller prostates, while the odds were similarly increased (2.4-fold) for men not achieving a peak urinary flow rate of 10 ml. per second. Estimated odds changed little when other cutoff points were considered for peak urinary flow rate (15 ml. per second) or prostate volume (40 ml.). These results, based on randomly selected white men, suggest a somewhat stronger, albeit modest, relationship among symptoms, prostate size and urinary flow rate than previously reported in clinic based studies. The strength of these relationships is comparable to that found with other diseases.

Cohort Studies↗
PubMed1995

Do prostate size and urinary flow rates predict health care-seeking behavior for urinary symptoms in men?

OBJECTIVES: To estimate the association between health care-seeking behavior for urinary dysfunction and clinical, physiologic, and anatomic measures of disease. METHODS: A randomly selected sample (n = 475) of men aged 40 to 79 years from Olmsted County, Minnesota, was administered a previously validated questionnaire that assessed the frequency of and bother associated with urinary symptoms and health care-seeking behavior in the past year. Peak urinary flow rates were measured with a standard urometer and prostatic volume was determined by transrectal ultrasound. RESULTS: Overall, 21 of the 475 men (4%) had seen a doctor in the past year for urinary symptoms. Men with moderate to severe symptoms (American Urological Association [AUA] Symptom Scores > 7) were 3.4 times as likely (95% confidence interval [CI] = 1.4, 8.3) to have sought medical care in the past year as men with none to mild symptoms. Men with enlarged prostates (> 40 mL) were 3.9 times as likely to have sought health care (95% CI = 1.6, 9.6), whereas men with depressed peak urine flow rates (< 10 mL/s) were only slightly more likely to have sought health care for urinary symptoms (odds ratio = 2.1, 95% CI = 0.7, 6.5). Overall, 76% of men who had sought medical care had prostatic enlargement, depressed peak urine flow rates, or moderate-severe symptoms (sensitivity). In contrast, only 55% of men who did not seek health care for urinary symptoms in the past year had mild symptoms, normal prostatic volume, and normal peak urine flow rates (specificity). CONCLUSIONS: These data suggest that clinical, physiologic, and anatomic measures of prostatism do not adequately distinguish the men who seek medical care for their urinary symptoms from those who do not. There remain some factor(s) that apparently lead some men with minor disease to seek care and that prevent men with measurable disease from seeking care.

Adult↗
PubMed1995

Sexual function of men ages 40 to 79 years: the Olmsted County Study of Urinary Symptoms and Health Status Among Men.

OBJECTIVES: Knowledge of male sexual function is somewhat limited because of a lack of current population-based data. This study provides information on sexual function and satisfaction in a population-based sample of men. METHODS: Men aged 40 to 79 years (n = 2115) were selected randomly from the Olmsted County population for the baseline component of a prospective cohort study (the Olmsted County Study of Urinary Symptoms and Health Status Among Men) during 1989-1990. The men completed a self-administered questionnaire that included questions about sexual concerns, performance, satisfaction, drive, and erectile dysfunction. RESULTS: For all five sexual parameters queried, the prevalence of problems and dysfunction increased with age. A comparison of men aged 70 to 79 years with men aged 40 to 49 years suggested that older men were more worried about sexual function (46.6% vs 24.9%), had worsened performance compared with a year ago (30.1% vs 10.4%), expressed extreme dissatisfaction with sexual performance (10.7% vs 1.7%), had absent sexual drive (25.9% vs 0.6%), and reported complete erectile dysfunction when sexually stimulated (27.4% vs 0.3%). Logistic regression analyses suggested that sexual dissatisfaction was significantly associated with erectile dysfunction, decreased libido, and the interaction between erectile dysfunction and libido, but not age. CONCLUSIONS: These population-based cross-sectional data corroborate the previously reported age-related decrease in sexual function. The age-related increase in dissatisfaction could, however, be accounted for primarily by the age-related increase in erectile dysfunction, decreased libido, and the interaction between erectile dysfunction and decreased libido.

Adult↗
PubMed1995

The role of community-based longitudinal studies in evaluating treatment effects. Example: benign prostatic hyperplasia.

To determine the appropriateness and effectiveness of medical interventions, it is necessary to understand both the natural history of the conditions the interventions are intended to treat or prevent, and the normal reference ranges of tests used in diagnosis and management. The acquisition of this information through clinic-based studies can yield misleading conclusions owing to selection bias. What appears to be intervention-related variation in outcomes may be variation in the magnitude and form of selection bias. To minimize selection bias, population-based studies are required. Results from the Olmsted County Study of Urinary Symptoms and Health Status Among Men were used to show how a population-based longitudinal study of the natural history of benign prostatic hyperplasia (BPH) can complement research programs of the BPH Patient Outcomes Research Team. Population-based studies of disease natural history are a necessary part of medical outcomes research, and deserve greater emphasis in the medical treatment effectiveness research initiative of the Agency for Health Care Policy and Research.

Community Health Planning↗
PubMed1995

Sampling strategies in a statistical approach to clinical classification.

This paper studies the sampling strategies for the Expert Network (EexNet), a statistical learning system used for patient record classification at the Mayo Clinic. The goal is to achieve high accuracy classification at an affordable computational cost in very large applications. The learning curves of ExpNet were observed with respect to the choice of training resources, the size, vocabulary coverage and category coverage of a training set, and the category distribution over training instances. A method combining advantages of different sampling strategies is proposed and evaluated using a large training corpus. As a result, Expert Network has achieved its nearly-optimal classification accuracy (measured by average precision) using a relatively small training set, with a fast real-time response which satisfies the needs of human-machine interaction.

Expert Systems↗
PubMed1995

Medical information retrieval and WWW browsers at Mayo.

Medical information retrieval from "Master Sheet" entries specially indexed for research retrieval has been part of the Mayo culture since 1909. Providing easy to use and universally available WWW access to these and other patient information databases at Mayo via browsers, shines a bright light on issues of privacy and confidentiality, user authentication, need to know, data transmission security, and technical details of interfacing disparate databases on a spectrum of platforms to many types of workstations using a variety of browsers. We review our recent experience, and generalize pertinent issues.

Computer Communication Networks↗