Biomedical subjects

M M Wagner

Publications and source records attributed to M M Wagner.

At least 19 recordsLinked to original sources

PubMed2001

A national agenda for public health informatics.

The American Medical Informatics Association 2001 Spring Congress brought together the public health and informatics communities to develop a national agenda for public health informatics. Discussions on funding and governance; architecture and infrastructure; standards and vocabulary; research, evaluation, and best practices; privacy, confidentiality, and security; and training and workforce resulted in 74 recommendations with two key themes: (1) all stakeholders need to be engaged in coordinated activities related to public health information architecture, standards, confidentiality, best practices, and research and (2) informatics training is needed throughout the public health workforce. Implementation of this consensus agenda will help promote progress in the application of information technology to improve public health.

Congresses as Topic↗

PubMed2001

The emerging science of very early detection of disease outbreaks.

A surge of development of new public health surveillance systems designed to provide more timely detection of outbreaks suggests that public health has a new requirement: extreme timeliness of detection. The authors review previous work relevant to measuring timeliness and to defining timeliness requirements. Using signal detection theory and decision theory, the authors identify strategies to improve timeliness of detection and position ongoing system development within that framework.

Bioterrorism↗

PubMed2001

Value of ICD-9 coded chief complaints for detection of epidemics.

To assess the value of ICD-9 coded chief complaints for early detection of epidemics, we measured sensitivity, positive predictive value, and timeliness of Influenza detection using a respiratory set (RS) of ICD-9 codes and an Influenza set (IS). We also measured inherent timeliness of these data using the cross-correlation function. We found that, for a one-year period, the detectors had sensitivity of 100% (1/1 epidemic) and positive predictive values of 50% (1/2) for RS and 25% (1/4) for IS. The timeliness of detection using ICD-9 coded chief complaints was one week earlier than the detection using Pneumonia and Influenza deaths (the gold standard). The inherent timeliness of ICD-9 data measured by the cross-correlation function was two weeks earlier than the gold standard.

Disease↗

PubMed2001

Accuracy of ICD-9-coded chief complaints and diagnoses for the detection of acute respiratory illness.

ICD-9-coded chief complaints and diagnoses are a routinely collected source of data with potential for use in public health surveillance. We constructed two detectors of acute respiratory illness: one based on ICD-9-coded chief complaints and one based on ICD-9-coded diagnoses. We measured the classification performance of these detectors against the human classification of cases based on review of emergency department reports. Using ICD-9-coded chief complaints, the sensitivity of detection of acute respiratory illness was 0.44 and its specificity was 0.97. The sensitivity and specificity using ICD-9-coded diagnoses were no different. These properties of excellent specificity and moderate sensitivity, coupled with the earliness and electronic availability of such data, support the use of detectors based on ICD-9 coding of emergency department chief complaints in public health surveillance.

Acute Disease↗

PubMed1999

In vitro pharmacology of cryptophycin 52 (LY355703) in human tumor cell lines.

PURPOSE: Cryptophycin 52 (LY355703) is a new member of the cryptophycin family of antitumor agents that is currently undergoing clinical evaluation for cancer chemotherapy. The mechanism of action of the cryptophycin class of compounds is associated with an action on microtubules. This report details the pharmacological profile of this new clinical compound in a panel of human tumor cell lines. METHODS: Antiproliferative effects of cryptophycin 52 were measured indirectly by detection of the metabolic reduction of alamarBlue. Cytoxicity was assessed by enzymatic dye activation (calcein AM) combined with dye exclusion (ethidium homodimer) and by clonogenicity assay. Cell cycle effects were evaluated using flow cytometry and fluorescence microscopy. RESULTS: Both antiproliferative and cytotoxic effects of cryptophycin 52 were concentration- and time-dependent. IC50 values for antiproliferative activity in both solid and hematologic tumor cell lines were in the low picomolar range, and without exception, were significantly below values for the antimitotic agents paclitaxel and vinblastine. Flow cytometry and microscopic examination of tumor cells treated with cryptophycin 52 indicated that they accumulated in the mitotic phase of the cell cycle. Cryptophycin 52 was tested for its sensitivity to multidrug-resistance in several paired cell lines in which a sensitive parental line was matched with a multidrug-resistant derivative line. The resistant lines have been shown to over express Pgp and/or MRP multidrug-resistance transport factors. Compared to other antimitotic agents (paclitaxel, vinblastine, vincristine), the potency of cryptophycin 52 was shown to be minimally affected in multidrug-resistant cells compared to their sensitive parental lines. CONCLUSION: Cryptophycin 52 has potent antimitotic, antiproliferative and cytotoxic activity in in vitro human tumor cell models. It is significantly more potent and less sensitive to multidrug resistance mechanisms than other antimitotic antitumor agents currently used in cancer therapy. These characteristics may translate into therapeutic advantages for the clinical use of cryptophycin 52 in cancer chemotherapy.

Antineoplastic Agents↗

PubMed1999

[Interpretation of pair diagnosis with the Giessen test. An algorithm and a computer program to determine types].

An algorithm is given in order to quantify the similarity of a couple's test profile in the Giessen-Test as concerns that 16 typical test profiles discovered by Brähler and Brähler (1993). The German Giessen-Test is a personality-inventory based on psychoanalysis. The Euklidian distance was chosen as a measuring unit. The identification of that typical test profile to which any couple belongs succeeds very easily, a task which is otherwise only possible with difficulty. However, any allocation is merely for reasons of description, not based on statistical decisions. As a special service, the respective computer programme is placed at everyone's disposal.

Algorithms↗

PubMed1999

The use of an explanation algorithm in a clinical event monitor.

Clinical event monitors (CEMs) seek to improve patient care and reduce its cost by prompting clinicians to take actions that have these effects. To persuade clinicians to act, CEMs have used prewritten-text explanations. However, we encountered limitations of prewritten-text explanations in our CEM. Therefore, we decided to implement an advanced method for explanation (Suermondt's method for belief-network explanation). This method is promising, but whether it is generally applicable to all of clinical event monitoring and whether it is as efficacious as prewritten-text explanations remain areas for future research.

Algorithms↗

PubMed1999

A feasibility study of two methods for end-user configuration of a clinical event monitor.

We developed and evaluated a feature that allows users to control what types of clinical information are delivered to them. Using a paper or web-based configuration form, users turn individual alerts and sets of results on or off, and set how they are delivered. We used usage rates to evaluate this feature. Of 16 residents who had received clinical information from our clinical event monitor, 4 (25%) made at least one change (range 10-25). Of 41 interns, 5 (12.2%) made at least one change (range 5-91). The difference was borderline significant (p < 0.1). 5/7 web users changed preferences through a dial-up connection from home. More users used the web-based preference form than the paper form. This difference may be due to the better accessibility of the web-based form. A survey established that this feature was not as highly utilized as anticipated partly because the initial (default) preference setting was acceptable and partly because the users were too busy to customize their alert settings. We conclude that user configuration of a system that delivers information using a web-based preference form is feasible and may become important as the volume of information and number of available communication channels increase.

Attitude to Computers↗

PubMed1999

Design of a clinical notification system.

We describe the requirements and design of an enterprise-wide notification system. From published descriptions of notification schemes, our own experience, and use cases provided by diverse users in our institution, we developed a set of functional requirements. The resulting design supports multiple communication channels, third party mappings (algorithms) from message to recipient and/or channel of delivery, and escalation algorithms. A requirement for multiple message formats is addressed by a document specification. We implemented this system in Java as a CORBA object. This paper describes the design and current implementation of our notification system.

Algorithms↗

PubMed1998

Mobile workers in healthcare and their information needs: are 2-way pagers the answer?

The ability to have access to information relevant to patient care is essential within the healthcare environment. To meet the information needs of its workers, healthcare information systems must fulfill a variety of functional requirements. One of these requirements is to define how workers will interact with the system to gain the information they need. Currently, most healthcare information systems rely on users querying the system via a fixed terminal for the information they desire; a method that is inefficient because there is no guarantee the information will be available at the time of their query and it interrupts their work flow. In general, clinical event monitors--systems whose efficacy relies on the delivery of time-critical information--have used e-mail and numeric pagers as their methods to deliver information. Each of these methods, however, still requires the user to perform additional steps, i.e., log into an information system in order to attain the information about which the system is alerting them. In this paper we describe the integration and use of 2-way alphanumeric pagers in CLEM, the UPMC Health System's Clinical Event Monitor, and how the use of these pagers addresses the information needs of mobile workers in healthcare.

Attitude of Health Personnel↗

PubMed1998

Preferences of interns and residents for E-mail, paging, or traditional methods for the delivery of different types of clinical information.

We elicited from medical house staff their preferences for e-mail and alphanumeric pager as communication channels for the delivery of 18 different types of clinical information about their inpatients. For each type, we calculated the proportion of users who preferred delivery by e-mail, pager, both, or neither (usual delivery). For 14/18 (78%) types, more users preferred delivery by pager than by the other options. For 2/18 (11%) types, e-mail was preferred. For 2/18 (11%) types, more users preferred redundant delivery using both channels. For no types did more users prefer neither, meaning that the information would be delivered by traditional channels, if any. We conclude that medical house staff in the inpatient setting prefer to receive many types of clinical information by pager. The reason may be that they otherwise would have to query clinical information systems for these data, which is wasteful of their time and introduces delays into the process of care. Additionally, we found significant inter-user variability, suggesting that it may be useful for the notification services of an enterprise to employ user profiles for the delivery of clinical information.

Attitude of Health Personnel↗

PubMed1998

Optimal use of communication channels in clinical event monitoring.

We argue that the optimal use of communication channels in clinical event monitors is an important design consideration for these systems. We review the state-of-the-art in selection of communication channels, including our current approach--allowing users to choose the communication channel by which the event monitor sends each notification. We describe a new approach that we are in the process of developing. In this new approach, we view event monitoring as the decision of whether and how to send new patient data to a clinician and apply the principle of maximum expected utility to this decision problem. Our initial experience with this approach suggests that notifying clinicians of normal patient data may be of high utility. We also found that methods for explanation in uncertain reasoning may be necessary in this approach.

Communication↗

PubMed1997

Representing and developing temporally abstracted knowledge as a means towards facilitating time modeling in medical decision-support systems.

The utilization of the appropriate level of temporal abstraction is an important aspect of time modeling. We discuss some aspects of the relation of temporal abstraction to important knowledge engineering parameters such as model correctness, ease of model specification, knowledge availability, query completeness, inference tractability, and semantic clarity. We propose that versatile and efficient time-modeling formalisms should encompass ways to represent and reason at more than one level of abstraction, and we discuss such a hybrid formalism. Although many research efforts have concentrated on the automation of specific temporal abstractions, much research needs to be done in understanding and developing provably optimal abstractions. We provide an initial framework for studying this problem in a manner that is independent of the particular problem domain and knowledge representation, and suggest several research challenges that appear worth pursuing.

Artificial Intelligence↗

PubMed1997

Clinical event monitoring at the University of Pittsburgh.

Although the literature on event monitoring is extensive, it does not cover all issues that we encountered while developing an event monitor at our institution. We had to resolve issues related to event detection, scalability, what topics were suitable for asynchronous decision support, and overlap of efforts of other groups at the institution attempting to improve quality and lower cost of care. In this paper, we describe our experience deploying CLEM, the clinical event monitor at the University of Pittsburgh with emphasis on these topics.

Academic Medical Centers↗

PubMed1997

Use of CLIPS for representation and inference in a clinical event monitor.

We developed a clinical event monitor that is currently deployed in an inpatient setting. We selected CLIPS as the basis for its KB and inference engine. This paper describes the considerations that went into that decision, how we represented drug and laboratory knowledge in CLIPSs, and how we extended CLIPS to deal with temporal inferences. We also review the published literature about the use of CLIPS in medicine.

Clinical Pharmacy Information Systems↗

PubMed1996

Transition from high school to work or college: how special education students fare.

Results are reported from the National Longitudinal Transition Study of Special Education Students. Dropout rates were high: 30% of students with disabilities dropped out of high school, and another 8% dropped out before entering high school. The average dropout with disabilities was 18 years old at the time of leaving but had earned less than half the credits needed to graduate. Employment successes were strongly related to taking a concentration (four courses) in vocational education. Youths with learning disabilities or speech impairments were most likely to approach the rate of employment found in the general population. Postsecondary education was low: 37% of high school graduates with disabilities had attended a postsecondary school, compared with 78% of high school graduates generally. Students with hearing or visual impairments were most likely to attend college. Students with disabilities were significantly more likely to be poor than were youths in the general population, and poverty tended to exacerbate the impact of having a disability. Impoverished students with disabilities were less likely than wealthier students with disabilities to be enrolled in those postsecondary education and training programs that could enable them to break out of poverty. When employed, the poorer students with disabilities earned significantly less per year than did those from wealthier families. Placement in regular education (rather than special education) was associated both with better and worse postschool outcomes. Students with sensory or motor disabilities appeared to benefit from regular education placement. However, for many students, more time in regular education was associated with a higher likelihood of course failure, which was a strong predictor of dropping out of school.

Adolescent↗

PubMed1996

Free-text fields change the meaning of coded data.

Researchers have advocated the supplementation of coded fields with free-text fields in electronic medical records (EMRs) to provide clinicians with flexibility during data entry. They cite advantages of more complete data capture and improved clinician acceptance and use of the EMR. However, free text may have the disadvantage of changing the meaning of coded data, which causes lower data accuracy for applications that cannot read free text. We studied the free-text entries that clinicians made during the recording of medication data. We found that these entries changed the meaning of coded data and lowered data accuracy for the medical decision-support system (MDSS) in our EMR. We conclude that supplemental free-text entries made by clinicians frequently alter the meaning of coded data.

Abstracting and Indexing↗

PubMed1996

Representing CARE rules in a decision-theoretic formalism.

Improvement in the performance of reminder systems may be facilitated by the use of new representations. A decision-theoretic representation, for example, may enable a reminder system to represent and reason about the probabilities that a reminder will be a true or a false alarm and the relative utilities of these events. We extended a previously described decision-theoretic model to include such events. The model now represents explicitly the uncertainty, costs, and benefits of sending a reminder. We also extended the model to remove an assumption of reminder independence. As a step towards testing a hypothesis that this approach will support better performance than a rule-based approach, we analyzed a set of CARE rules and showed that our representation can represent these rules.

Decision Support Techniques↗