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Biomedical subjects

J H Barnes

Publications and source records attributed to J H Barnes.

13 recordsLinked to original sources
PubMed2001

Precision and accuracy of commercial laboratories' ability to classify positive and/or negative allergen-specific IgE results.

BACKGROUND: Accurate and reliable evaluation of the presence or absence of allergen-specific IgE is important in the differential diagnosis of allergic disease. A variety of different commercial tests are available for this purpose. There are few data available to judge how the results of these different tests compare with one another in everyday use. OBJECTIVE: To examine prospectively the extent of comparability among specific IgE results from different laboratories. METHODS: Six diagnostic laboratories employing five different methods to assay specific IgE were selected. Aliquots from 26 serum samples that contained variable levels of IgE specific to 17 common aeroallergens were sent in triplicate to each study laboratory during a 6-week time period. Results were reported numerically and by class scores and then compared by examining their concordance using Kendall's W nonparametric statistical test. In addition, cut-off values were compared by a best agreement analysis using reported results. Reproducibility was determined using precision profiles based upon the coefficient of variation among triplicates for each allergen across the range of reported results. RESULTS: In all, 7,813 tests were analyzed. Concordance among different assays in commercial use with one exception was not good. This was particularly true around the cut-off region where most assays demonstrated high imprecision. The Pharmacia CAP System used by two different laboratories demonstrated highly comparable results with good precision. Some assays were reproducible but not accurate. Others were neither reproducible nor accurate. CONCLUSIONS: The results of this study indicate that not all commercial laboratories/assays for specific IgE provide reproducible and accurate data. Significant potential for misdiagnosis was detected for some reported results. Methods were identified that do give sensitive, accurate, and reproducible results.

Allergens↗
PubMed2000

Analytic precision and accuracy of commercial immunoassays for specific IgE: establishing a standard.

BACKGROUND: Different laboratory assays are used to detect and measure specific IgE antibodies. No standard exists to assess their analytic performance. OBJECTIVE: We sought to analyze reported specific IgE results from different laboratories on the same serum samples for their accuracy and precision. METHODS: Blinded serum samples (26) containing variable levels of specific IgE to 17 common aeroallergens were sent on 3 different occasions through normal channels to 6 laboratories that used 5 different test procedures. Six samples were presented as a dilution series. Laboratory-assay performance was assessed by analyzing the reported results (n = 12, 708) by using ordinary least squares regression with slope coefficients, the t statistic, SEs, confidence intervals, and R (2) values. These were compared with a theoretic ideal assay as the reference. RESULTS: Analysis revealed that one system used in two different laboratories performed nearly as well as the ideal standard, with an overall average slope (0.97; range, 0.91-1.01), SE (0.05; range, 0.02-0.16), R (2) value (93%; range, 0.64-0.99), and coefficient of variation (10.3%; range, 6%-14%). Extensive variability was observed in the other 4 laboratory-assay systems with respect to overall average slope (0.76; range, 0.11-1.24), SE (0.19; range, 0.03-0.95), R (2) value (53%; range, 0.00-0.98), and coefficient of variation (19%; range, 5%-49%). For some specific allergens, some laboratories-assays were not able to detect serial dilutions of the same sample. CONCLUSIONS: One commercial system used in two different laboratories performed nearly as well as the ideal standard. Four of the laboratories-assays for specific IgE antibodies demonstrated substandard overall performance with multiple instances of poor precision and accuracy, particularly for certain allergens, such as weeds and molds.

Air Pollutants↗
PubMed1996

A systems-based disease management model: achieving optimal health care outcomes.

In this article, the "disease management system model" is presented, which is applicable to health care providers practicing in community, hospital, and long-term care settings. The core service of patient information for diabetic care is used to demonstrate how the model integrates individual system components involved in health care delivery.

Diabetes Mellitus↗
PubMed1994

Convenience or calamity? Pharmaceutical study explores the effects of sample frame error on research results.

Survey results of a nationwide sample frame did not differ from those of a statewide sample frame with respect to questions that were professional/procedural in nature or that dealt with putative industry knowledge. However, on questions that were attitudinal in nature, the sample frames differed significantly. Because of this, the authors conclude that using a geographically narrow convenience sample may or may not result in frame error, depending on the information being sought.

Data Collection↗
PubMed1993

Modeling physicians' prescribing decisions for patients with panic disorder.

The authors asked general and family practitioners to rate the importance of several items relating to the prescribing of drug products for patients with panic disorder. Physicians preferred to use benzodiazepines alone and in combination with antidepressants for treatment, regardless of the presence or absence of phobic avoidance. Adverse drug events, efficacy, and patient characteristics were found to be important considerations when physicians prescribe medication. Educational and promotional strategies for pharmaceutical manufacturers and marketers are discussed.

Antidepressive Agents↗
PubMedDate not supplied

Meta-analysis of correlates of diabetes patients' compliance with prescribed medications.

This study quantitatively integrated the results of independent research papers containing correlates of objectively measured diabetes patients' compliance with prescribed medications. A total of 183 correlations were extracted from 26 studies. Separate meta-analytic syntheses were conducted to calculate average correlations for different subsets of studies, each of which represented homogeneous results. In general, emotional stability, internal and external motivations, perceived benefit, and supportive structure were positively associated with patients' compliance; perceived barriers and negative social environment were correlated with poor compliance. The directions of relationships of knowledge and age with compliance varied, depending on other study characteristics.

Diabetes Mellitus↗