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PubMed1997

Laboratory tests in evaluation of acute febrile illness in pediatric emergency room patients.

The rising costs of health care and the movement for health care reform have focused attention on methods of cost containment. Of routine laboratory and radiologic procedures, complete blood cell count (CBC) and determination of serum electrolyte values rank as high as 2nd and 9th in overall cost. We retrospectively studied use of the clinical laboratory to aid diagnosis of an acute infectious event in a pediatric emergency department population. For 5 months, we reviewed medical records of pediatric patients younger than 15 years brought to the emergency department because of a febrile episode. Of 155 cases reviewed, electrolyte concentrations were determined in 108 patients and CBC in 155. In all patients, either culture or rapid test for streptococcal organisms was performed. In addition, 838 pediatric patients with similar symptoms but who did not undergo laboratory testing were monitored for 100 days. Measures of effectiveness including sensitivity, specificity, positive and negative predictive values, and likelihood ratio were used to correlate specific laboratory findings with antibiotic therapy, serious bacterial disease, and culture positivity. Electrolyte abnormalities were found largely to be dismissed clinically, with the major clinical response consisting of parental education about hydration. The CBC profile was evaluated, with white blood cell count (WBC) indicator limits of > 10,000, > 10,000 but < 15,000, and > 15,000/mm3, and differentiated into absolute neutrophil count, neutrophil percent, and band cell percent. Temperature was evaluated as an independent variable. Insofar as serious bacterial disease and culture positivity, sensitivity was uniformly low (70%), and specificity was only marginably acceptable for WBC > 15,000 (77%). Both positive predictive values and likelihood ratio were low with respect to predicting either serious bacterial disease or culture positivity, emphasizing the limited usefulness of these clinical laboratory measurements. The best hematologic predictors of serious bacterial disease or culture positivity were obtained with automated hematologic analyzers and exceeded manual differential measurement of neutrophil percent and band cell percent. In addition, we correlated the administration of antibiotics with the various hematologic parameters and discovered that WBC > 15,000, regardless of cause, almost uniformly resulted in treatment (positive predictive value, 93.5%; likelihood ratio, 5.60). These findings support the use of automated hematology analyzer-derived measurements and question the use of manual differential counts, unless specific issues are to be addressed. Furthermore, the findings seem to support more reliance on clinical impression and less on laboratory values.

Acute Disease↗
PubMed1980

Clinical laboratory proficiency test performance. Its relationship to structural, process and environmental variables.

This comparative analysis of clinical laboratories was intended to develop a more quantitative understanding of environmental, structural, and process variables and their relationships to the quality of laboratory services. The quality of laboratory services was defined as analytic capability demonstrated on proficiency-test specimens of the College of American Pathologists. Independent variables describing the laboratory environment, as well as structural and process aspects of management, were obtained from management reports, staffing records, and workload reports. Although correlations between the eight proficiency testing indices and the independent variables were generally low, a number of significant correlates were evident in three areas: bacteriology, parasitology, and qualitative hematology. Environmental variables describing organizational size were related to proficiency, as were variables dealing with accreditation by the College of American Pathologists and time accredited by the College of American Pathologists. The education and experience of personnel and the percentage of specialized supervisors were related to proficiency-testing success in bacteriology and parasitology. Empirical evidence suggests that the size of the laboratory indirectly affects proficiency in these three tested areas. Presumably, this relationship is mediated through specialization of work and reinforcement of learning. Few significant correlates were evident in the five remaining areas tested: chemistry, quantitative hematology, blood bank, immunology, and syphilis serology. Despite the concentration of personnel resources and other assets in larger laboratories, size appeared to have no effect on proficiency-testing performance in these five areas.

Bacteriology↗
PubMed1988

Penicillin-resistant Streptococcus pneumoniae. Report of a case and results of a clinical laboratory proficiency survey in Minnesota.

An elderly woman with Streptococcus pneumoniae meningitis relatively resistant (minimum inhibitory concentration, [MIC] = 0.12 micrograms/mL) to penicillin is reported. The occurrence of penicillin-resistant pneumococcal infections is reviewed and management discussed. Because of the importance of recognition of resistant pneumococci, a state-wide clinical laboratory survey was conducted to determine the accuracy of susceptibility testing for this isolate. Of 111 laboratories completing the survey, only 26 performed the 1-microgram oxacillin disk test as recommended by the National Committee for Laboratory Standards (NCCLS). When laboratories were analyzed according to hospital size, the proficiency in performing the proper susceptibility testing was 55% (6 of 11) for hospitals with more than 400 beds versus 3% (2 of 58) for hospitals with fewer than 100 beds (P less than 0.0001 by Fisher's exact test). This contrasts with reported surveys by the College of American Pathologists (CAP), and reasons for this are explored. Guidelines for laboratory testing of S. pneumoniae are reviewed, and additional study of clinical proficiency with attention to laboratory size is recommended.

Aged↗
PubMed2001

A proposal for harmonising laboratory performance assessment criteria in national asbestos fibre counting schemes.

Four European national asbestos fibre counting proficiency testing schemes have been studied in order to compare their criteria for the assessment of laboratory performance. Performance assessment is based on each laboratory's results after counting a certain number of samples. Two methods are currently being applied. To be classified 'satisfactory' laboratories must obtain at least 75% of normalised counts lying within defined performance limits (in three schemes), or the median and coefficient of variation of normalised counts must be within performance limits (in the fourth scheme). Differences in the numbers of test samples mean that the schemes are operating with different selectivity in assessing their laboratories' performances. Differences in the percentage of laboratory results falling within performance limits indicate that the schemes do not operate the same confidence probability in correctly assessing individual counts. It means that some schemes may be more lenient than others. This paper discusses two proposals to move towards harmonisation of the asbestos fibre counting proficiency testing schemes: (i) standardisation of the number of samples used for laboratory assessment and (ii) changes to the criteria to establish the limits of satisfactory performance.

Asbestos↗
PubMed2006

The performance of laboratories analysing heavy metals in the Workplace Analysis Scheme for Proficiency (WASP).

This paper discusses the proficiency of laboratories analysing identical test samples representative of metals in air in the Workplace Analysis Scheme for Proficiency (WASP) and the variability of results from laboratories used to assess personal exposure in the workplace. Over 11 years, the performance of laboratories has significantly improved for lead, cadmium and chromium. Laboratories show better agreement when using inductively coupled plasma-atomic emission spectroscopy (ICP-AES) than flame atomic absorption spectroscopy (FAAS) when analysing chromium, but not when analysing lead and cadmium. Data from the proficiency testing scheme show that for a customer to have confidence that a measurement value does not exceed the workplace exposure limit the analytical result would have to be <134 microg m(-3) for lead and 23 microg m(-3) for cadmium for an 8 h sample and 129 microg m(-3) for lead, 21 microg m(-3) for cadmium and 429 microg m(-3) for chromium for a 4 h sample (for samples with relatively soluble matrices), before considering the further uncertainties due to sampling. The performance criterion for satisfactory performance (+/-8.3%) was found to be appropriate as long as laboratories participated consecutively in all rounds. Estimates of the overall uncertainty of results from ICP-AES and FAAS analysis were shown to meet the criteria in EN482. Samples from some types of workplace environments are more difficult than the WASP test material to dissolve into solution, so it is expected that estimates of uncertainty are larger for less soluble analytes and matrices. WASP has now initiated a programme to help laboratories assess their performance with more complex matrices.

Air Pollutants, Occupational↗
PubMed1998

The LabBase system for data management in large scale biology research laboratories.

MOTIVATION: The development of laboratory information management systems (LIMSs) for large scale biology research projects can be a challenging problem. Many such projects generate complex datasets via complex procedures that undergo continuous refinement. A key software challenge is to simplify the database-development task so that databases can be built and modified quickly enough to keep pace with changing project-requirements. RESULTS: LabBase extends the facilities offered by relational database systems to simplify the task of creating databases for large scale biology research projects. LabBase provides a structural object data model, similar to ACEDB, and adds to this the concepts of Materials, Steps, and States: Materials are objects representing the identifiable things that participate in a laboratory protocol; Steps are objects reporting the results of a laboratory or analytical procedure; and States are objects denoting places in a laboratory protocol. The system provides a data definition language for succinctly defining laboratory databases, and operations for conveniently storing and retrieving data in such databases. The system also provides support for workflow management. LabBase is implemented in Perl5 and provides a natural interface for laboratory application programs written in Perl. AVAILABILITY: The software is freely available. Contact the authors. CONTACT: nat@jax.org

Computational Biology↗
PubMed2006

Is quality assurance in semen analysis still really necessary? A view from the andrology laboratory.

Quality assurance (QA) is a fundamental part of laboratory medicine, of which internal and external QA (proficiency testing) is an important part. In a recent debate article published in Human Reproduction, it was argued that it was no longer necessary for semen analysis to be subject to QA, primarily because it is now being performed robustly and there is little evidence that it has any real clinical value. In response to this argument, it is suggested here that although there may have been some improvements in the training of laboratory scientists, recent studies have shown that the techniques of semen analysis are still poorly implemented at many locations. Moreover, as the impact of the introduction of QA into the andrology laboratory begins to take effect, there are a growing number of studies showing that the results of semen analysis do correlate well with natural conception and some assisted reproductive technologies. However, since the processes of QA are central to the principles of total quality management, which in turn underpins the process of laboratory accreditation, QA needs to remain in the andrology (and embryology) laboratory so that they can achieve the same accredited status as medical laboratories in other disciplines.

Andrology↗
PubMed2003

50 years of the Institute for Laboratory Animal Research (ILAR): 1953-2003.

The history of the Institute for Laboratory Animal Research (ILAR) begins, as does all of laboratory animal science, with the ancient philosophers, anatomists, and physiologists whose work presaged the use of animals in biomedical research and the institutions that arose due to this use. Modern laboratory animal science and medicine began in the late 1940s and early 1950s as five Chicago-area institutions hired veterinarians to manage their animal facilities. Each of these men became instrumental in the founding of the organizations that collectively make up the laboratory animal science and medicine organizations. Nathan Brewer, one of the "Chicago five," was particularly influential in the founding of ILAR. His boss at the University of Chicago, Dr. Paul Weiss, a member of the National Academy of Sciences (NAS), asked him to help establish a committee with the stated purpose of preparing recommendations to the NAS to develop an office to obtain information on sources of supply for research animals. This office became ILAR, and Brewer was chairman of its first report on the diseases of laboratory animals. He was also a founding diplomat and first president of the American College of Laboratory Animal Medicine. This history recognizes the thoughtful and energetic contributions of scientists and veterinarians to ILAR. It provides a 50-year overview of the programs and reports of ILAR and highlights examples where these reports have been adopted by scientists and federal agencies and incorporated into national laws and policies governing the use of animals in research both in the United States and in other countries.

Academies and Institutes↗
PubMed2006

Reliability of mutagen sensitivity assay: an inter-laboratory comparison.

Mutagen sensitivity is regarded as a genetic susceptibility phenotype for various cancers; it is cytogenetically based and probably involves a number of genes from different DNA repair pathways. This assay has been used in a number of laboratories in the field of epidemiology, where it has been investigated and appears to be a useful susceptibility biomarker for epidemiological studies assessing cancer risks at the population level. One concern about phenotypic assays, such as the mutagen sensitivity assay, has been that there could be wide variation in results depending on the timing of the assay (within individual variation), the individual performing the assay (within observer variation) and the laboratory where the assay has been performed (inter-laboratory variation). We conducted an inter-laboratory comparison study between the Memorial Sloan-Kettering Cancer Center and M. D. Anderson, in which we assessed all these concerns. We did not find any significant variation in any of the assays. The correlation was high for all tests. The good concordance rate between laboratories supports the continued use of the mutagen sensitivity assay by different laboratories, and demonstrates its potential to identify at-risk subgroups among normal individuals and cancer patients alike.

Environmental Exposure↗
PubMed2003

UK laboratory intercomparison on internal dosimetry.

A laboratory intercomparison for internal dose assessment from a variety of intake scenarios is described. This is the first UK intercomparison using the revised ICRP Human Respiratory Tract and biokinetic models. Four United Kingdom laboratories participated and six cases were assessed. Overall, the agreement in internal dose assessments between laboratories was considered satisfactory with 79% of the assessed committed effective doses, e(50), for cases within a band of +/- 40% of the median value. The range (highest/lowest) in e(50) estimated by the laboratories was smallest (1.2) for a case involving inhalation of 137Cs. The range was greatest (6.0) for a case involving a wound with, and possible inhalation of, 238Pu, 239Pu and 241Am; the variation between laboratories in assessment of intakes could not be considered to be satisfactory in this case. Judgements on the most appropriate data to use in estimating intakes, choice of parameter values for use with the ICRP models and allowing for the effects of treatment with DTPA were important sources of variability between laboratories.

Body Burden↗
PubMed2006

Laboratory and field studies of naps and caffeine as practical countermeasures for sleep-wake problems associated with night work.

STUDY OBJECTIVES: To evaluate the effects of napping, caffeine, and napping plus caffeine on performance and alertness in both laboratory and field settings. DESIGN: (1) Laboratory Study: parallel-groups design with random assignment to 1 of 4 experimental conditions. (2) Field Study: crossover design. SETTING: Sleep laboratory and field settings. PARTICIPANTS: (1) Laboratory Study: 68 healthy individuals; (2) Field Study: 53 shiftworkers who worked nights or rotating shifts. INTERVENTIONS: (1) Laboratory Study: an evening nap opportunity before the first 2 of 4 consecutive simulated night shifts plus placebo taken all 4 nights, caffeine taken nightly, the combination of the nap and caffeine conditions, or placebo. (2) Field Study: an evening nap on the first 2 of 4 consecutive night shifts plus caffeine taken nightly versus placebo taken nightly without naps. MEASUREMENTS AND RESULTS: (1) Laboratory Study: Napping, caffeine, and their combination all improved alertness and performance as measured by Maintenance of Wakefulness Test and Psychomotor Vigilance Task, but the combination of napping and caffeine was best in improving alertness. (2) Field Study: Napping plus caffeine improved performance as measured by Psychomotor Vigilance Test and decreased subjective sleepiness in individuals working the night shift. CONCLUSIONS: Napping plus caffeine helps improve performance and alertness of night-shift workers.

Adolescent↗
PubMed2003

Loss of laboratory instruction in American medical schools: erosion of Flexner's view of "scientific medical education.".

There has been a steep decline in the number of hours devoted to laboratory instruction in American medical schools. Medical students attending 1 of the 3 Washington DC medical schools now spend less than 10% of their first 2 basic science years in a laboratory. The paucity of laboratory instruction represents a reversal of the gains made in American medical education after the Flexner report and may partly account for our nation's missing physician-scientists. This situation is not expected to improve anytime soon, given the expenses that would be required to divert research-intensive faculty to laboratory instruction. The expenses would be particularly onerous for medical schools under intensive managed care pressures. Because it is unlikely that many American medical schools have either the will or means to make substantive changes in their laboratory-based curricula, novel solutions to restoring laboratory-based medical education may be required.

Curriculum↗
PubMed1994

First-year residents' caring, medical knowledge, and clinical judgment in relation to laboratory utilization.

PURPOSE: To investigate first-year residents' levels of caring (concern for others' well-being), medical knowledge, and clinical judgment in relation to their levels of laboratory utilization. METHOD: Self-report questionnaires about caring, knowledge, and judgment were given in 1986-87 to 36 first-year residents in a three-year internal medicine residency program of the McGaw Medical Center of Northwestern University. Inpatient laboratory utilization data obtained from structured chart audits over a one-year period were used to construct comparable diagnosis- and severity-specific physician practice profiles, from which the residents received overall utilization scores for laboratory test charges. Statistical methods included Cronbach's alpha reliability coefficient and multiple regression analysis. RESULTS: The multiple regression analysis showed that medical knowledge was an independent predictor of increased laboratory utilization (standardized beta = .54, p < .04, partial R2 = .07); clinical judgment was an independent predictor of decreased utilization (standardized beta = -.53, p < .05, partial R2 = .06); and caring was unrelated to utilization (standardized beta = .15, ns, partial R2 = .01). CONCLUSION: The finding that clinical judgment was related to less laboratory utilization suggests that future research should investigate the decision-making concomitants of judgment to better understand its translation into resource utilization. It is possible that the relationship between medical knowledge and laboratory utilization is developmentally specific, and thus the knowledge of more experienced physicians, who would likely be more precise decision makers than first-year residents, may be related to decreased rather than increased utilization.

Chicago↗
PubMed1995

Effect of experience on medical students' attitudes toward animal laboratories in pharmacology education.

BACKGROUND: Medical students' attitudes toward the use of animal laboratories in pharmacology courses may form a useful source of evaluative information about the laboratories' educational effectiveness. METHOD: In 1992-93, 144 second-year students at the Indiana University School of Medicine were surveyed--before and after completing four hands-on laboratories using dogs--for their assessments of educational and moral aspects of animal laboratories. Statistical analysis involved chi-square and Student's t test. RESULTS: Of the 144 students in the course, 143 responded to the first survey and 86 responded to the second. From before to after the lab experiences, the percentage of students who agreed that the labs would reinforce/had reinforced the lecture material increased from 38% to 69%. In both surveys, 10% of the students objected to the use of any animals in labs, and 24% (before) and 21% (after) objected to the use of dogs. Whereas the percentage agreeing that the labs involved a morally wrong use of animals rose from 11% to 22%, the percentage disagreeing with that notion rose from 53% to 61%. Between 50% and 60% of the students in both surveys opposed doing the labs by computer simulation or videotaped demonstration. CONCLUSION: Most students indicated that the laboratory experiences enhanced their understanding of the actions of drugs, were preferable to alternatives that did not use animals, and did not involve an immoral use of animals. On the other hand, the results suggest that the number of students who have negative feelings about the use of animals in laboratories, though small, tends to be larger than the number who express these feelings to faculty.

Animals↗
PubMed1993

Ordering of laboratory work in the management of pediatric burn patients: technical note.

A large number of laboratory tests are often ordered in the management of acutely burned patients. Administration of large volumes of fluid and frequent ventilator changes prompt many facilities to utilize ordering protocols. Forty-five consecutive acutely burned pediatric patients with burns measuring 25% or more of total body surface area (TBSA) sustained within 24 hours before admission were reviewed. Laboratory determinations were made at each shift and as indicated by changes in condition. Abnormal or critical values during the first 5 postinjury days were identified for electrolytes, renal function indices, complete blood counts (CBCs), glucose, and arterial blood gas (ABG) levels. Blood drawn for the laboratory tests was also measured. In the first 5 days postburn a total of 8303 laboratory determinations were made. Of these, 186 produced abnormal values. Four were critical values that were not expected from previous determinations. Of the four unexpected critical values obtained, two would have been picked up by our present standard noninvasive monitors. Six percent of estimated blood volume was used to perform laboratory tests. These results demonstrate that significant abnormal laboratory values are uncommon even in severely injured pediatric burn patients and that the ordering of these tests should be individualized based on patient examination and the use of noninvasive monitoring.

Adolescent↗
PubMed2002

Cyclosporin monitoring in Australasia: survey of laboratory practices in 2000.

Therapeutic drug monitoring of cyclosporin has been established as part of the routine clinical management of patients following organ transplantation for some 20 years. The current practices of laboratories in Australia and New Zealand have been surveyed for the year 2000 to update previous similar surveys in the light of considerable changes in CsA formulation (now exclusively Neoral throughout Australasia), assay methods, and blood sampling strategies. The results, representing 93% of CsA laboratories in Australasia (n = 44), found that there was still a plethora of approaches adopted within each organ type for monitoring the established trough (C0) CsA concentration. There was a considerable uptake of 2-hour post-dose sampling (C2) monitoring practices, as demonstrated by assay requests to the responding laboratories, particularly in renal and liver transplantation (46% of centers). Most of these laboratories were also assaying C0 and/or to a much lesser extent, so-called limited sampling strategy AUC (lssAUC) samples at this time. The mFPIA (on TDx and AxSYM analyzers) were still strongly represented (54%) (relatively consistent with international data from the UKQAS proficiency testing scheme at this time) despite on-going concerns expressed in the literature about these methods. However, the Cedia assays had made considerable impact so soon after their introduction with 22% of the laboratories using Cedia or Cedia Plus (Microgenics or Roche Diagnostics; Sydney, Australia) methods. There were a wide variety of dilution protocols adopted in many centers for measuring samples above calibration ranges (such as C2 samples), and hence there was scope for improvement to fully validated techniques. Few centers (16%) made any attempt at interpretation of their results, many seeing their role as purely "measuring" (i.e., an analytical role), not "monitoring" (i.e., including assay and result interpretation). Despite many detailed attempts at providing international or national guidelines for CsA monitoring, etc., there is still considerable scope for improving the quality of the laboratory services offered in this complex as well as expensive area. Several respondents volunteered their support for further Australasian CsA monitoring consensus guidelines.

Australia↗
PubMed2000

Pregnancy outcome of personnel in Swedish biomedical research laboratories.

Possible hazardous effects of laboratory work on the reproduction outcomes of female laboratory personnel in Sweden from 1990 to 1994 were investigated in a questionnaire-based study (n = 1052) by comparison with personnel in non-laboratory departments. The individual woman constituted the primary sampling unit, with her pregnancies defined as the unit of analysis. Allowance for dependence between different pregnancies of the same woman was considered by applying random effect models. With regard to spontaneous abortions, no elevated odds ratio was found for laboratory work in general, but an odds ratio of 2.3 and a 95% confidence interval of 0.9 to 5.9 (n = 856) was connected to working with chloroform. The odds ratio for large for gestational age infants in association with the mother's laboratory work was 1.9 (confidence interval, 0.7 to 5.2). The result with regard to spontaneous abortion partly supports previously reported increased risks of miscarriage related to laboratory work with solvents.

Abortion, Spontaneous↗
PubMed2001

Electronic laboratory reporting: barriers, solutions and findings.

Electronic laboratory reporting can improve surveillance for notifiable conditions. Building on standards for message structure and content, we have implemented an electronic laboratory reporting system by building on the infrastructure created for the Indiana Network for Patient Care (INPC). The system has proven reliable in delivering results and scalable to multiple laboratories over 36 months of use. In April 2000, the system identified over 1,000 cases of notifiable conditions from the laboratories at four different laboratories. Our experience in developing the system has highlighted the need for improved compliance with HL7 result message formats by the laboratory information systems and more structured reporting of results for tests such as microbiology including consistent use of the abnormal flag.

Clinical Laboratory Information Systems↗