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Surveillance programs for chronic viral hepatitis in three health departments.

Although chronic hepatitis B and chronic hepatitis C are diseases of public health importance, only a few health departments nationally have chronic viral hepatitis under surveillance; these programs rely primarily on direct reporting by medical laboratories. We conducted an evaluation to determine if lessons from these programs can guide other health departments. Between December 2002 and February 2003, we visited the Connecticut Department of Public Health, the Multnomah County Health Department in Portland, Oregon, and the Minnesota Department of Health to determine the capacity of their chronic hepatitis registries to monitor trends and provide case management. We found that the registries facilitated investigations of potentially acute cases by identifying previously known infections, and aided prevention planning by pinpointing areas where viral hepatitis was being diagnosed. For chronic cases, case management (defined as the process of ensuring that infected individuals and their partners receive medical evaluation, counseling, vaccination, and referral to specialists for treatment when indicated) was provided for hepatitis B in Multnomah County, but was limited in other programs; barriers included resource constraints, difficulties confirming chronic infection, and privacy concerns. Finding innovative ways to overcome these barriers and improve case management is important if chronic hepatitis surveillance is to realize its full potential.

Adult↗

Architectural design and tools to support the transparent access to hospital information systems, radiology information systems, and picture archiving and communication systems.

The fragmentation of the electronic patient record among hospital information systems (HIS), radiology information systems (RIS), and picture archiving and communication systems (PACS) makes the viewing of the complete medical patient record inconvenient. The purpose of this report is to describe the system architecture, development tools, and implementation issues related to providing transparent access to HIS, RIS, and PACS information. A client-mediator-server architecture was implemented to facilitate the gathering and visualization of electronic medical records from these independent heterogeneous information systems. The architecture features intelligent data access agents, run-time determination of data access strategies, and an active patient cache. The development and management of the agents were facilitated by data integration CASE (computer-assisted software engineering) tools. HIS, RIS, and PACS data access and translation agents were successfully developed. All pathology, radiology, medical, laboratory, admissions, and radiology reports for a patient are available for review from a single integrated workstation interface. A data caching system provides fast access to active patient data. New network architectures are evolving that support the integration of heterogeneous software subsystems. Commercial tools are available to assist in the integration procedure.

Computer Systems↗

Clinical and laboratory evaluation of a radioimmunoassay kit for measuring the mid-molecule fraction of parathyrin.

We report the results of a laboratory and clinical evaluation of a commercial kit procedure (Immuno Nuclear Corp.) for measuring the mid-region of the parathyrin molecule. The estimated dose at 50% binding averaged 130 pmol/L, and the minimum detectable concentration was 14 pmol/L. The within-assay CV was less than or equal to 6.6%, the between-assay CV less than or equal to 12.5%. Relative analytical recoveries of various parathyrin fragments averaged 93% (intact, amino acid residues 1-84), 100% (midregion, 44-68), less than 0.01% (N-terminal, 1-34), and less than 0.01% (C-terminal, 69-84). Correlation of results obtained for 59 patients' samples with a radioimmunoassay for midregion/C-terminal parathyrin performed by the Mayo Medical Laboratory yielded the equation INC = 1.16 (Mayo)-1.94 pmol/L (r = 0.971). Clinical evaluation indicates that the INC results for parathyrin correlate with the diagnoses of patients at least as well as the results obtained with the Mayo assay; in some cases, the INC procedure better distinguishes hyperfunction from normal parathyroid function. The INC procedure can be easily performed in hospital laboratories, with a 4-h turnaround time for results.

Adult↗

Medical monitoring. What is it, how can it be improved?

Little has been published about optimizing medical monitoring protocols, although monitoring accounts for over half of all medical laboratory tests. Monitoring is a form of surveillance consisting of repeated testing intended to detect a specified change in a patient indicating a change in his prognosis, need for treatment or need for a change in treatment. The concept of monitoring overlaps with those of screening and diagnosis. One may monitor a physiologic or pathologic process, a therapeutic or noxious agent, comparing results with the patient's previous results or with a group reference range. Pertinent questions include: what are the indications, what is to be monitored, which tests are to be used, when to start, how frequently to test, when to stop. Preliminary improvement of monitoring protocols may be achieved by applying common sense guidelines for medical decision making; using best estimates of test characteristics, of possible risks and benefits of testing, not testing, treating and not treating. Sensitivity analysis may help determine when further clinical research is needed.

Decision Making↗

[50 years of clinical chemistry, first hand experience].

Approximately since 1945, progress in the field of photometric analysis also found its way into the laboratories of clinical chemistry. These techniques almost completely replaced the then prevailing gravimetric and titrimetric methods. At the same epoch, many of the biochemical reagents which up to then had to be prepared by the clinical laboratories themselves with great expenditure of work became commercially available. The increasing number of analytical orders could only be mastered thanks to the newly developed analyzers. Novel microliter techniques made it possible to diminish drastically the volumes of samples and reagents necessary. The radioimmunoassay opened up new analytical dimensions, the limits of detection and of quantification were expanded downwards to the picomol range. Soon afterwards, enzymes and/or fluorochromes were used as markers in immunoassays. The development of monoclonal antibodies constituted further important progress in this field. The latest revolutionary invention is doubtlessly the polymerase chain reaction (PCR), and related techniques. These methods are bound to bring about fundamental change not only in clinical chemistry but in the medical laboratory diagnostics in general.

Antibodies, Monoclonal↗

Population-based measurement of quality of diabetes care using HbA1c values in the state of Thuringia/Germany.

INTRODUCTION/HYPOTHESIS: There remains insufficient knowledge about the quality of diabetes therapy regarding structure, process and outcome given by primary care in Thuringia, and elsewhere in Germany. The project assesses a means of determining the quality of diabetes therapy in primary care by analysis of HbA1c values within a broad territory. METHODS: HbA1c tests of Thuringian patients were analysed by 20 participating medical laboratories between January 1 and March 31, 2002; each HbA1c test was identified by the postal code of the Thuringian General Practitioner (GP) who ordered the test and adjusted by a standardisation procedure (mean normal of healthy subjects 5 %). The German state of Thuringia (population of 2,421,871) consists of 23 urban and rural districts. This format was also used in the present study. RESULTS: Twenty participating laboratories contributed 59,702 HbA1c tests from diabetic patients in Thuringia. Adjusted mean HbA1c of entire Thuringia: 6.75 %, 36.4 % of all HbA1c tests were above 7.0 % and 3,0 % of all HbA1c values above 10.0 %. Regional percentage of HbA1c tests above 7.0 % ranged between 28.2 % and 47.3 %. Regional percentage of HbA1c tests above 10.0 % ranged between 1.8 % and 4.8 %. Subgroup analyses comparing urban vs. rural districts showed significantly lower mean HbA1c (6.72 % vs. 6.75 %, CI 0.01 - 0.06, p < 0.01) and percentage of HbA1c tests above 7 % (8.19 % vs. 8.24 %, CI 0.01 - 0.08, p < 0.01) in urban areas. CONCLUSIONS: Mean HbA1c as an indicator of glycaemic control of diabetes patients in primary care in Thuringia was good. The percentage of patients who need immediate medical intervention to prevent acute complications varied between districts, which is indicative for differences in quality of diabetes care in Thuringia. However, the proposed method is still experimental and has not yet been evaluated. Consequently, considerable bias might influence the results.

Biomarkers↗

Direct costs of severe sepsis in three German intensive care units based on retrospective electronic patient record analysis of resource use.

OBJECTIVE: To determine the direct costs of severe sepsis patients in German intensive care units (ICUs). DESIGN: Retrospective electronic data analysis. SETTING: Three adult intensive care units (surgical/medical) in three university hospitals in Germany. PATIENTS: 385 patients identified by standard definitions as suffering from severe sepsis. MEASUREMENTS AND RESULTS: A bottom-up approach was used to determine the direct ICU cost on actual resource use (medication, laboratory tests, microbiological analysis, disposables, and clinical procedures) for patients with severe sepsis. To determine the total direct costs, center-specific personnel and basic bed ("hotel") costs were added to total resources consumed. Average hospital mortality of severely septic patients was 42.6%. Mean ICU length of stay (LOS) was 16.6 days. Survivors stayed on average 4 days longer than nonsurvivors. The mean direct ICU costs of care were 23,297+/-18,631 euros per patient and 1,318 euros per day. In comparison, average daily charges being paid for an ICU patient by the health care system in Germany are 851 euros (based on official statistics). Nonsurvivors were more expensive than survivors in total direct costs (25,446 vs. 21,984 euros) and in per day direct cost (1,649 vs. 1,162 euros). Medication makes up the largest part of the direct costs, followed by expenses for personnel. CONCLUSIONS. Patients with severe sepsis have a high ICU mortality rate and long ICU LOS and are substantially expensive to treat. Nonsurviving septic patients are more costly than survivors despite shorter ICU LOS. This is due to higher medication costs indicating increased efforts to keep patients alive.

Adult↗

Epidemiology of vancomycin-induced neutropenia in patients receiving home intravenous infusion therapy.

BACKGROUND: Vancomycin is frequently used to manage serious resistant gram-positive infections. Neutropenia, whose epidemiology has not been well characterized, is a potentially serious adverse event associated with the use of vancomycin. OBJECTIVE: To characterize the incidence and risk factors for development of vancomycin-induced neutropenia in patients treated with home intravenous vancomycin therapy. METHODS: A retrospective chart review was conducted of adult patients receiving vancomycin therapy through the University of New Mexico Home Intravenous Infusion Clinic between January 1998 and December 2004. Data collection included demographics, comorbid conditions, dose and duration of vancomycin therapy, indications for vancomycin use, vancomycin concentrations, all concurrent medications, laboratory data, culture and susceptibility data, reasons for antibiotic alteration or discontinuations, all other recorded adverse events, management of adverse events, and outcomes of adverse events. RESULTS: A total of 372 charts of patients managed through the clinic were reviewed and 114 patients treated with vancomycin were identified. Fourteen (12%) cases of vancomycin-induced neutropenia were identified; 4 (3.5%) cases included a reduction in absolute neutrophil count to 500 cells/mm3 or less. The mean +/- SD duration of vancomycin therapy and time to neutropenia were 32 +/- 29 and 26 +/- 15 days, respectively. Laboratory monitoring was performed on a weekly basis and resolution of vancomycin-induced neutropenia occurred promptly after discontinuation. Total vancomycin doses used and serum concentrations were not associated with the development of neutropenia. CONCLUSIONS: Vancomycin-induced neutropenia may occur at a higher frequency than previously reported. Clinicians should monitor hematologic parameters at least weekly in patients receiving home intravenous vancomycin therapy.

Adult↗

Evaluation of four automated methods for determination of whole blood cyclosporine concentrations.

Cyclosporine is a widely used and potent immunosuppressant drug with a narrow therapeutic index. Therefore, cyclosporine concentrations should be monitored closely. Various automated immunologic methods for cyclosporine whole blood determinations are available. Two new methods, fluorescence polarization immunoassay (FPIA) for the AxSYM by Abbott Laboratories, Chicago, IL, and the cloned enzyme donor immunoassay (CEDIA) by Boehringer Mannheim, Mannheim, Germany, have been introduced. In addition, Dade Behring improved its enzyme multiplied immunoassay (EMIT) assay. The present study evaluated all 3 new methods in comparison with high-performance liquid chromatography (HPLC) and the FPIA for the TDx analyzer. We measured whole blood cyclosporine concentrations of 179 samples obtained from 127 patients after kidney, bone marrow, heart-lung, and liver transplantation. All 4 automated immunologic methods can be used for routine measurement of cyclosporine whole blood concentrations. Disadvantages, such as higher cross-reactivity (Abbott TDx, CEDIA) or a limited linearity range (EMIT), are accompanied by advantages, such as a high precision (Abbott TDx) or an easy sample handling procedure (CEDIA). Information presented in this article should help to find the most adequate cyclosporine method for each medical laboratory.

Antibodies, Monoclonal↗

Comparability of method results and performance in a national external quality assessment scheme between 1993 and 2003 using thyroid associated analytes as examples.

Six thyroid analytes (free and total triiodothyronine and thyroxine, thyrotropin and thyroglobulin) have been followed up over a 10 year period in a national external quality assessment scheme (EQAS) organised by the Institute for Standardisation and Documentation in the Medical Laboratory (INSTAND). I. The following points were observed: II. The introduction of samples with properties similar to patient serum (filtered, recalcified defibrinated plasma without stripping) improved performance and inter-method comparability for the free thyroid hormones. III. In general, the performance in EQAS has improved over the past decade, an exception being thyroglobulin, where precision has improved at the expense of inter-method comparability. IV. Regular statistical analysis of EQAS data allows adjustment of target ranges to be made when necessary. V. Analytes which are not dependent on binding proteins--thyrotropin and the total thyroid hormones--give rise to similar performance when stripped and spiked plasma or recalcified non-stripped and spiked plasma is used as sample. VI. Whereas certain analytes have had a relatively constant number of participants over the past decade (total thyroid hormones), others have shown a drastic increase (free thyroxine from 67 to 620; thyrotropin from 295 to 724) reflecting the medical demand for the analytes.

Biomarkers↗

Simulation studies of a wide area health care network.

There is an increasing number of efforts to install wide area health care networks. Some of these networks are being built to support several applications over a wide user base consisting primarily of medical practices, hospitals, pharmacies, medical laboratories, payors, and suppliers. Although on-line, multi-media telecommunication is desirable for some purposes such as cardiac monitoring, store-and-forward messaging is adequate for many common, high-volume applications. Laboratory test results and payment claims, for example, can be distributed using electronic messaging networks. Several network prototypes have been constructed to determine the technical problems and to assess the effectiveness of electronic messaging in wide area health care networks. Our project, Health Link, developed prototype software that was able to use the public switched telephone network to exchange messages automatically, reliably and securely. The network could be configured to accommodate the many different traffic patterns and cost constraints of its users. Discrete event simulations were performed on several network models. Canonical star and mesh networks, that were composed of nodes operating at steady state under equal loads, were modeled. Both topologies were found to support the throughput of a generic wide area health care network. The mean message delivery time of the mesh network was found to be less than that of the star network. Further simulations were conducted for a realistic large-scale health care network consisting of 1,553 doctors, 26 hospitals, four medical labs, one provincial lab and one insurer. Two network topologies were investigated: one using predominantly peer-to-peer communication, the other using client-server communication.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Communication Networks↗

Clinical applications of whole-blood PCR with real-time instrumentation.

BACKGROUND: As the genetic basis of many human diseases is being discovered, there is increasing need for the detection of single-nucleotide polymorphisms/mutations in medical laboratories. We describe an innovative approach that combines PCR amplification directly on whole blood and real-time detection PCR technology (WB-RTD PCR). METHODS: We compared WB-RTD PCR with the method for extracted DNA-RTD PCR for the detection of mutations in the prothrombin (n = 94), factor V Leiden (n = 49), and hemochromatosis (n = 22) genes. Mutation detection on the Roche LightCycler was based on use of fluorescence resonance energy transfer (FRET) probes and melting curve analysis. We also compared the WB-RTD PCR on the LightCycler and the ABI Prismtrade mark 7700 sequence detection system with minor groove- binding nonfluorescent quencher probes. RESULTS: We obtained complete concordance between both methods in assigning genotypes. We also demonstrated that the WB-RTD PCR method can be performed on real-time PCR instruments from Applied Biosystems and the LightCycler. Omission of the need for DNA extraction and gel electrophoresis allowed substantial labor and cost savings with this method. CONCLUSION: This approach has applications for testing other medically relevant single-nucleotide polymorphisms.

Blood↗

Physician-directed software design: the role of utilization statistics and user input in enhancing HELP results review capabilities.

The M.D. Rounds Report program was developed and implemented in June of 1992 as an adjunct to the HELP System at Rex Hospital. The program facilitates rapid access to information on allergies and current medications, laboratory results, radiology reports and therapist notes for a list of patients without physicians having to make additional menu or submenu selections. In planning for an upgrade of the program, utilization statistics and user feedback provided valuable information in terms of frequency of access, features used and unused, and the value of the program as a reporting tool in comparison to other online results reporting applications. A brief description of the functionality of the M.D. Rounds Report, evaluation of the program audit trail and user feedback, planned enhancements to the program, and a discussion of the prototyping and monitoring experience and the impact on future physician subsystem development will be presented.

Computer Systems↗

CytoBase: an electronic medical record for cervical cytology.

A partnership of medical laboratories in Ontario, Canada has developed and made operational a centralized interactive database of cervical cytology (Pap) reports. This system automatically registers some 60,000 reports monthly, which are submitted electronically from geographically diverse sources. Patient histories are provided on-line to authorized pathologists to support ongoing diagnoses. A formalized coding system has been developed to represent elements of Pap reports in machine readable format, including diagnosis, clinical information about the patient, specimen adequacy, methods of specimen collection and follow-up recommendations. The system operates over a private network based on Internet standards. A review of operations, which commenced June 1, 1996, provides insights into applied EMR technology.

Confidentiality↗