PubMed Health⌕ Search

Biomedical subjects

L Lenert

Publications and source records attributed to L Lenert.

14 recordsLinked to original sources
PubMed2001

Utility of B-type natriuretic peptide in the diagnosis of congestive heart failure in an urgent-care setting.

OBJECTIVES: The goal of this study was to evaluate the utility of a rapid "bedside" technique for measurement of B-type natriuretic peptide (BNP) in the diagnosis of congestive heart failure (CHF) in an urgent-care setting. BACKGROUND: B-type natriuretic peptide is a protein secreted from the cardiac ventricles in response to pressure overload. One potential application of measurements of BNP in blood is distinguishing dyspnea due to CHF from other causes. METHODS: B-type natriuretic peptide concentrations were measured in a convenience sample of 250 predominantly male (94%) patients presenting to urgent-care and emergency departments of an academic Veteran's Affairs hospital with dyspnea. Results were withheld from clinicians. Two cardiologists retrospectively reviewed clinical data (blinded to BNP measurements) and reached a consensus opinion on the cause of the patient's symptoms. This gold standard was used to evaluate the diagnostic performance of the BNP test. RESULTS: The mean BNP concentration in the blood of patients with CHF (n = 97) was higher than it was in patients without (1,076 +/- 138 pg/ml vs. 38 +/- 4 pg/ml, p < 0.001). At a blood concentration of 80 pg/ml, BNP was an accurate predictor of the presence of CHF (95%); measurements less than this had a high negative predictive value (98%). The overall C-statistic was 0.97. In multivariate analysis, BNP measurements added significant, independent explanatory power to other clinical variables in models predicting which patients had CHF. The availability of BNP measurements could have potentially corrected 29 of the 30 diagnoses missed by urgent-care physicians. CONCLUSIONS: B-type natriuretic peptide blood concentration measurement appears to be a sensitive and specific test to diagnose CHF in urgent-care settings.

Aged↗
PubMed2001

A rapid bedside test for B-type peptide predicts treatment outcomes in patients admitted for decompensated heart failure: a pilot study.

OBJECTIVES: The goal of this study was to determine if B-type natriuretic peptide (BNP) levels predict outcomes of patients admitted with decompensated heart failure. BACKGROUND: Treatment of decompensated congestive heart failure (CHF) has often been based on titration of drugs to relieve patient's symptoms, a case that could be made for attempting to also treat neurohormonal abnormalities. Because BNP reflects both elevated left ventricular pressure as well as neurohormonal modulation, we hypothesized that BNP might be useful in assessing outcomes in patients admitted with decompensated CHF. METHODS: We followed 72 patients admitted with decompensated New York Heart Association class III to IV CHF, measuring daily BNP levels. We then determined the association between initial BNP measurement and the predischarge or premoribund BNP measurement and subsequent adverse outcomes (death and 30-day readmission). RESULTS: Of the 72 patients admitted with decompensated CHF, 22 end points occurred (death: n = 13, readmission: n = 9). In these patients, BNP levels increased during hospitalization (mean increase, 233 pg/ml, p < 0.001). In patients without end points, BNP decreased (mean decrease 215 pg/ml). Univariate analysis revealed that the last measured BNP was strongly associated with the combined end point. In patients surviving hospitalization, BNP discharge concentrations were strong predictors of subsequent readmission (area under the receiver operator curve of 0.73). CONCLUSIONS: In patients admitted with decompensated CHF, changes in BNP levels during treatment are strong predictors for mortality and early readmission. The results suggest that BNP levels might be used successfully to guide treatment of patients admitted for decompensated CHF.

Adult↗
PubMed2000

Quality Enhancement Research Initiative for human immunodeficiency virus/acquired immunodeficiency syndrome: framework and plan. HIV-QUERI Executive Committee.

The Veterans Health Administration (VHA) sees approximately equal to 17,000 human immunodeficiency virus (HIV)-infected patients each year, which makes it the largest provider of HIV care in the United States. HIV causes chronic progressive disease that leads to early death. Newer combination antiretro viral treatments are effective but expensive and difficult to use. The HIV Quality Enhancement Research Initiative (HIV-QUERI) uses the QUERI process to identify high-risk and high-volume populations (step 1), which includes those already under VHA care for HIV, those who do not know of their infection, and those at risk for HIV. In identifying best practices (step 2), the HIV-QUERI will benefit greatly from existing guidelines for the care of established HIV infection, but gaps in knowledge regarding adherence to medication regimens and cost-effective screening are large. To identify existing practice patterns (step 3), the HIV-QUERI will develop a clean analytic data set based on Immunology Case Registry files and expand it through a survey of veterans. Interventions to improve care (step 4) will include national, regional, and site-specific feedback on performance relative to quality standards, as well as patient-level and provider-level interventions to improve adherence and support medical decision-making. To document that best practices improve outcomes and quality of life (steps 5 and 6), HIV-QUERI will track indicators on an ongoing basis by use of the Immunology Case Registry database and possible future waves of the survey. In addition, we will require that these issues be addressed in evaluations of HIV-QUERI interventions. In the present article, we present these steps within a framework and plan.

Benchmarking↗
PubMed2000

Validity and interpretation of preference-based measures of health-related quality of life.

Utilities are numeric measurements that reflect an individual's beliefs about the desirableness of a health condition, willingness to take risks to gain health benefits, and preferences for time. This report discusses the approaches to assess and compare the validity of methods used to assign utilities for cost-utility analysis. Threats to validity include construct underrepresentation and construct-irrelevant variance. Construct underrepresentation occurs when a stimulus presented to a judge fails to fully represent the depth and complexity of information required in actual judgments. Construct-irrelevant variation occurs when factors irrelevant to preferences influence measurements of utilities. Among several factors that cause construct-irrelevant variation are cognitive abilities, numeracy skills, emotions and prejudices, and the elicitation procedure. Commonly used elicitation methods (visual-analog scales, time tradeoff, and standard gamble) capture different facets of utilities (desirableness of states, time preferences, and risk attitude) to different degrees. The validity of an elicitation protocol depends (1) on the degree to which its scaling method captures the relevant facets of utility and (2) on the degree to which measurements are influenced by construct-irrelevant variation. Discrete-state health index models provide an alternative to direct elicitation of utilities and work by attaching fixed preference weights to observable health states. The creation of discrete-state models with current technologies requires the adoption of strong assumptions about the scaling properties of utilities. Future research must refine methods of eliciting utilities and identify sources of construct-irrelevant variability that reduce the validity of utility assessments. Because of the impact of variation in techniques on measurements, we do not recommend the combination of utilities elicited with different protocols in cost-utility analysis and do not recommend the display of cost-utility ratios from different studies in comparison or "league" tables.

Attitude to Health↗
PubMed1999

Relationship between age and patients' current health state preferences.

This article explores age differences in preferences for current health states, which is one way to measure trade-offs between "quantity of life" and the "quality" of those health states. Data are from 17,707 adult outpatients visiting 46 primary care, managed care practices. Patient preferences (utility) for their current health were assessed by standard gamble and time trade-off methods. Although older primary care patients' utility measurements for their current health were lower than other patient groups, most of the difference in value measurements was attributable to differences in health. Health providers should take care to assess individual preferences from all patients regardless of age.

Adolescent↗
PubMed1995

Potentially ineffective care. A new outcome to assess the limits of critical care.

OBJECTIVE: To examine the limits of the effectiveness of critical care through the study of patients for whom it was ineffective. DESIGN: We studied the relationship between resource use and long-term outcome (2-year follow-up) in 402 consecutively admitted critical care patients to develop a benchmark for ineffective applications of critical care. We defined an outcome called potentially ineffective care (PIC), developed and evaluated a model with an independent data set to predict PIC from a patient's response to treatment, and estimated the economic effects of limiting care after a prediction of PIC. SETTING: The combined medical and surgical intensive care unit at a 600-bed university teaching hospital. PATIENTS: Two groups of 402 consecutively admitted critical care patients, one from 1989, the other from 1991. MAIN OUTCOME MEASURES AND RESULTS: Based on observations from a two-dimensional plot of resource use vs benefit for 402 critical care patients, PIC was defined as resource use in the upper 25th percentile and survival for less than 100 days after discharge. Thirteen percent of the patients fell into the PIC category and used 32% of the resources. A product of the APACHE risk estimates on days 1 and 5 of at least 0.35 predicted 37% of PIC outcomes with a specificity of 98%. In a second data set, PIC outcome prediction had a sensitivity of 43% and a specificity of 94%, and a positive predictive value of 80%. For the hospital studied, reduction of intensity of treatment after a prediction of a PIC outcome would result in a reduction of hospital charges in the range of $1.8 million to $5 million per year. CONCLUSION: Patients in the PIC category consumed a large portion of the resources devoted to critical care at an academic teaching hospital. We suggest a change in focus from assessment of the quality of critical care and risk-adjusted mortality to an assessment of ineffective care based on outcome and resource use and a patient's response to treatment over time.

APACHE↗
PubMed1991

A free-text processing system to capture physical findings: Canonical Phrase Identification System (CAPIS).

The task of gathering detailed patient information from free-text medical records presents a significant barrier to clinical research. In this paper, we describe a prototype system for extracting physical examination findings from dictated admission summaries. Our computer program applies a concept-based free-text processing algorithm that identifies user-selected target physical examination findings. We are using the extraction system to enrich an existing clinical database. The system was evaluated by comparing the physical examination findings extracted by our computer program with findings extracted by an independent investigator. Our prototype system was able to recall 92 percent (sensitivity) of the relevant physical findings, with a precision of 96 percent (positive predictive value).

Algorithms↗
PubMed1991

A free-text processing system to capture physical findings: Canonical Phrase Identification System (CAPIS).

The task of gathering detailed patient information from free-text medical records presents a significant barrier to clinical research. In this paper, we describe a prototype system for extracting physical examination findings from dictated admission summaries. Our computer program applies a concept-based free-text processing algorithm that identifies user-selected target physical examination findings. We are using the extraction system to enrich an existing clinical database. The system was evaluated by comparing the physical examination findings extracted by our computer program with findings extracted by an independent investigator. Our prototype system was able to recall 92 percent (sensitivity) of the relevant physical findings, with a precision of 96 percent (positive predictive value).

Academic Medical Centers↗
PubMed1990

Aspirin, hydroxychloroquine, and hepatic enzyme abnormalities with methotrexate in rheumatoid arthritis.

Levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) in patients with rheumatoid arthritis from 5 centers involved in the Arthritis, Rheumatism, and Aging Medical Information System were correlated with the use of specific antirheumatic medications. Elevated levels of SGOT and SGPT were most frequent in patients taking salicylates and methotrexate (MTX) and least frequent in patients taking hydroxychloroquine. The combination of MTX and salicylates greatly increased the frequency of abnormal liver enzyme values. In contrast, the addition of hydroxychloroquine to a regimen of either MTX or aspirin essentially eliminated the SGOT and SGPT abnormalities. Results from all 5 centers were consistent and remained so after adjustment for age, sex, and disease duration. Knowledge of these important drug interactions may permit continuation of MTX therapy in patients in whom the drug might otherwise be discontinued.

Alanine Transaminase↗
PubMedDate not supplied

Improving drug dosing in hospitalized patients: automated modeling of pharmacokinetics for individualization of drug dosage regimens.

Many clinical useful drugs have a narrow range of blood concentrations which are both safe and efficacious. Inter-individual and intra-individual variations in drug disposition are important factors causing blood concentrations of drug to fall outside of the therapeutic range. Modeling of the pharmacokinetics of the individual offers an effective approach to the problem of variation in drug disposition. Previous approaches for the modeling of individual pharmacokinetics have required either extensive computations or access to computer software and hardware in the clinical environment, and special expertise to interpret the results. This paper describes a prototype computer program, PK Monitor, which can, when connected with an appropriate interface, automatically monitor drug dosing and recommend changes that may be required to obtain blood concentrations in the therapeutic range. The software can also detect the occurrence of change in drug disposition which will lead to concentrations outside of the therapeutic range, identify potentially erroneous blood concentration measurements, and assess the need for further blood concentration measurements. This program will be an integral part of the MENTOR therapeutic monitoring system of programs. PK Monitor awaits a complete evaluation with the rest of the MENTOR system, but preliminary simulations suggest reasonable sensitivity and specificity in monitoring for unexpected data and change.

Drug Administration Schedule↗
PubMedDate not supplied

What should be reported in a methods section on utility assessment?

BACKGROUND: The measurement of utilities, or preferences, for health states may be affected by the technique used. Unfortunately, in papers reporting utilities, it is often difficult to infer how the utility measurement was carried out. PURPOSE: To present a list of components that, when described, provide sufficient detail of the utility assessment. METHODS: An initial list was prepared by one of the authors. A panel of 8 experts was formed to add additional components. The components were drawn from 6 clusters that focus on the design of the study, the administration procedure, the health state descriptions, the description of the utility assessment method, the description of the indifference procedure, and the use of visual aids or software programs. The list was updated and redistributed among a total of 14 experts, and the components were judged for their importance of being mentioned in a Methods section. RESULTS: More than 40 components were generated. Ten components were identified as necessary to include even in an article not focusing on utility measurement: how utility questions were administered, how health states were described, which utility assessment method(s) was used, the response and completion rates, specification of the duration of the health states, which software program (if any) was used, the description of the worst health state (lower anchor of the scale), whether a matching or choice indifference search procedure was used, when the assessment was conducted relative to treatment, and which (if any) visual aids were used. The interjudge reliability was satisfactory (Cronbach's alpha = 0.85). DISCUSSION: The list of components important for utility papers may be used in various ways, for instance, as a checklist while writing, reviewing, or reading a Methods section or while designing experiments. Guidelines are provided for a few components.

Authorship↗
PubMedDate not supplied

Internet-based monitoring of patients with rheumatoid arthritis.

Patient-derived measures have been increasingly recognized as a valuable means for monitoirng patients with rheumatoid arthritis. One advantage of this data is that it can be collected remotely. This would allow more frequent and more rapid assessments, which could optimize therapeutic intervention and patient outcome.

Adult↗