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Biomedical subjects

L M Lau

Publications and source records attributed to L M Lau.

10 recordsLinked to original sources

Applying the desiderata for controlled medical vocabularies to drug information databases.

Medication history has always been an integral part of the patient's medical record. With the advent of the computerized medical record and the longitudinal clinical data repository, having the medication history has enabled the development of clinical decision support system that alerts for drug to drug interactions and drug allergies. Furthermore, medication data is increasingly being analyzed from a utilization and clinical outcomes standpoint. For these activities to occur, a controlled pharmacy vocabulary akin to a controlled medical vocabulary is essential. Drug information databases are well-established sources of information for pharmacy-related data and products. However, do they measure up as a controlled vocabulary? Recent experience reviewing drug information databases and integrating pharmacy-related information into a data dictionary in real-time clinical use at multiple health care institutions have revealed several challenges and issues. These are discussed according to Cimino's desiderata for controlled medical vocabularies.

Databases, Factual

Research review: a computer-based diagnostic model for individual case review.

A previous study found that Iliad, a diagnostic expert system, detects diagnostic errors missed by peer review organization (PRO) review. That study used volunteer physicians from an institution as gold standard reviewers, however. The article discusses a second experiment employing Utah PRO (UPRO) review physicians as gold standards. Iliad was compared with the Unified Clinical Data Set used by the UPRO and was found to detect otherwise unsuspected diagnostic errors. The confirmation rate of Iliad flags was much higher in the earlier study, however. No agreement was found between institution and UPRO physicians, but there was agreement between a unique physician (who was both an institution and UPRO physician) and each of the two groups. Because Iliad screens for potential diagnostic errors to be confirmed or denied by gold standard physician review, the different types of physicians in the two experiments might have been the cause.

Diagnostic Errors

Experience with a mixed semantic/syntactic parser.

The value of the computerized medical record is derived in part from the availability of medical information in a coded form accessible to manipulation by processes designed for automated decision support, medical research, and computer assistance in the management of health care delivery. To meet these needs medical reports captured and stored as natural language documents must be encoded. Below we discuss an ongoing formative process aimed at developing a natural language understanding system for chest x-ray reports. Comparative data showing the progress of this process is presented.

Hospital Information Systems

A natural language understanding system combining syntactic and semantic techniques.

A large proportion of the medical record currently available in computerized medical information systems is in the form of free text reports. While the accessibility of this source of data is improved through inclusion in the computerized record, it remains unavailable for automated decision support, medical research, and management of medical delivery systems. Natural language understanding systems (NLUS) designed to encode free text reports represent one approach to making this information available for these uses. Below we describe an experimental NLUS designed to parse the reports of chest radiographs and store the clinical data extracted in a medical data base.

Bayes Theorem

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

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

Inability of polyglycolic acid mesh to inhibit immediate post-radical pelvic surgery adhesions.

The ability of a polyglycolic acid (PGA)-derived mesh to limit the formation of immediate postoperative pelvic adhesions after radical resection of the pelvic viscera and peritoneum was investigated. Twenty female canines underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, and infracolonic omentectomy. The entire peritoneum of the pelvis and lower abdomen also was removed. In ten animals, a single layer of PGA mesh, tailored to cover the deperitonealized area, was sutured in place. Reperitonealization was not performed in control animals. Four weeks after initial surgery, animals were reexplored and killed. Adhesions to the anterior abdominal wall and pelvis were quantified and graded: (Table: See Text) These data indicate that the placement of a PGA mesh induces significant pelvic adhesions and potentiates the formation of pelvic abscesses.

Animals

Molecular genetic and morphological analyses of the African wild dog (Lycaon pictus).

African wild dog populations have declined precipitously during the last 100 years in eastern Africa. The possible causes of this decline include a reduction in prey abundance and habitat; disease; and loss of genetic variability accompanied by inbreeding depression. We examined the levels of genetic variability and distinctiveness among populations of African wild dogs using mitochondrial DNA (mtDNA) restriction site and sequence analyses and multivariate analysis of cranial and dental measurements. Our results indicate that the genetic variability of eastern African wild dog populations is comparable to that of southern Africa and similar to levels of variability found in other large canids. Southern and eastern populations of wild dogs show about 1% divergence in mtDNA sequence and form two monophyletic assemblages containing three mtDNA genotypes each. No genotypes are shared between the two regions. With one exception, all wild dogs examined from zoos had southern African genotypes. Morphological analysis supports the distinction of eastern and southern African wild dog populations, and we suggest they should be considered separate subspecies. An eastern African wild dog breeding program should be initiated to ensure preservation of the eastern African form and to slow the loss of genetic variability that, while not yet apparent, will inevitably occur if wild populations continue to decline. Finally, we examined the phylogenetic relationships of wild dogs to other wolf-like canids through analysis of 736 base pairs (bp) of cytochrome b sequence and showed wild dogs to belong to a phylogenetically distinct lineage of the wolf-like canids.

Africa, Eastern

Quality assessment and patient participation in care by means of a touch-screen computer.

Hospital characteristics vary greatly across a geographic area such as a state. Hospital peer groups internally exhibit similar characteristics and can be used as a basis for the analysis of data, the dissemination of information, and the adoption of continuous quality improvement project results. This paper reflects the efforts made toward the identification of hospital peer groups within the state of Michigan. Hospital characteristics data for fiscal year 1992 were obtained from the American Hospital Association's Annual Survey of Hospitals and the Health Care Financing Administration's MEDPRO database. Thirteen peer group clusters have been identified, reviewed, and commented on by the state's hospital association and have met general approval by hospital administrators across the state. The established peer groups are being used to identify the differences in patterns of care among hospitals in the state. The peer groups also are being used for the feedback of comparable data and the identification of hospitals for participation in continuous quality improvement projects. The next research objective is to experiment with other clustering techniques and other inpatient populations. The consistency of the peer groupings across all clustering techniques and across both Medicare and total inpatient populations will be studied.

Feasibility Studies