SUMMARYBackground.Urinary tract infection (UTI) in the United States is the most common bacterial infection, and urine cultures often make up the largest portion of workload for a hospital-based microbiology laboratory. Appropriately managing the factors affecting the preanalytic phase of urine culture contributes significantly to the generation of meaningful culture results that ultimately affect patient diagnosis and management. Urine culture contamination can be reduced with proper techniques for urine collection, preservation, storage, and transport, the major factors affecting the preanalytic phase of urine culture.Objectives.The purposes of this review were to identify and evaluate preanalytic practices associated with urine specimens and to assess their impact on the accuracy of urine culture microbiology. Specific practices included collection methods for men, women, and children; preservation of urine samples in boric acid solutions; and the effect of refrigeration on stored urine. Practice efficacy and effectiveness were measured by two parameters: reduction of urine culture contamination and increased accuracy of patient diagnosis. The CDC Laboratory Medicine Best Practices (LMBP) initiative's systematic review method for assessment of quality improvement (QI) practices was employed. Results were then translated into evidence-based practice guidelines.Search strategy.A search of three electronic bibliographic databases (PubMed, SCOPUS, and CINAHL), as well as hand searching of bibliographies from relevant information sources, for English-language articles published between 1965 and 2014 was conducted.Selection criteria.The search contained the following medical subject headings and key text words: urinary tract infections, UTI, urine/analysis, urine/microbiology, urinalysis, specimen handling, preservation, biological, preservation, boric acid, boric acid/borate, refrigeration, storage, time factors, transportation, transport time, time delay, time factor, timing, urine specimen collection, catheters, indwelling, urinary reservoirs, continent, urinary catheterization, intermittent urethral catheterization, clean voided, midstream, Foley, suprapubic, bacteriological techniques, and microbiological techniques.Main results.Both boric acid and refrigeration adequately preserved urine specimens prior to their processing for up to 24 h. Urine held at room temperature for more than 4 h showed overgrowth of both clinically significant and contaminating microorganisms. The overall strength of this body of evidence, however, was rated as low. For urine specimens collected from women, there was no difference in rates of contamination for midstream urine specimens collected with or without cleansing. The overall strength of this evidence was rated as high. The levels of diagnostic accuracy of midstream urine collection with or without cleansing were similar, although the overall strength of this evidence was rated as low. For urine specimens collected from men, there was a reduction in contamination in favor of mi...

Objectives This article presents evidence from a systematic review of the effectiveness of four practices (assay selection, decision point cardiac troponin (cTn) threshold selection, serial testing, and point of care testing) for improving the diagnostic accuracy for Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) in the Emergency Department. Design and Methods The CDC-funded Laboratory Medicine Best Practices (LMBP™) Initiative systematic review A6 Method for Laboratory Best Practices was used. Results The current guidelines (e.g., ACC/AHA) recommend using cardiac troponin assays with a 99th percentile upper reference limit (URL) diagnostic threshold to diagnose NSTEMI. The evidence in this systematic review indicates that contemporary sensitive cTn assays meet the assay profile requirements (sensitivity, specificity, PPV, and NPV) to more accurately diagnose NSTEMI than alternate tests. Additional biomarkers did not increase diagnostic effectiveness of cTn assays. Sensitivity, specificity, and negative predictive value (NPV) were consistently high and low positive predictive value (PPV) improved with serial sampling. Evidence for use of cTn point of care testing (POCT) was insufficient to make recommendations, though some evidence suggests cTn POCT may result in reduction to patient length of stay and costs. Conclusions Two best practice recommendations emerged from the systematic review and meta-analysis of literature conducted using the LMBP™ A6 Method criteria: Testing with cardiac troponin assays, using the 99th percentile URL as the clinical diagnostic threshold for the diagnosis of NSTEMI and without additional biomarkers, is recommended. Also recommended is serial cardiac troponin sampling with one sample at presentation and at least one additional sample taken a minimum of 6 hours later to identify a rise or fall in the troponin level. Testing with high-sensitivity cardiac troponin assays, at presentation and again within 6 hours, is the recommended evidence-based best practice testing algorithm for optimized NSTEMI diagnosis.

Grounded theory and methods related to expert practice development in medical laboratory science were described using data from a large national survey of medical laboratory scientists (MLS) overlaid on findings from analysis of expert practice domains reported in nursing literature. An extensive focus group/expert review iterative process followed by a survey of MLS practitioners produced 25 critical thinking (CT) behaviors important in expert practice. Factor analysis was applied to discern common threads or themes linking the CT behaviors. The 25 important CT behaviors were reduced to a 7-factor structure representing constructs underlying the individual, observable CT behaviors. This 7-factor structure in MLS was compared to the 7 practice domains identified in expert nursing practice. The comparison yielded commonality between MLS and nursing in CT behaviors observed in the 7 expert practice domains of both professions: professional techniques, caring communication, growing professionally, setting priorities, practicing with judgment, anticipating/revising, and creating unique meaning. Emergent grounded theory is that (1) critical thinking is a metaprocess that facilitates learning by interlinking the more basic processes associated with different learning orientations: cognitivist, behaviorist, humanist (affective), and situated/contextual learning, (2) CT behaviors are observable events following from the CT metaprocess, and (3) observations of CT behaviors increase as practice advances from novice to expert. Identification and definition of CT behaviors, i.e., practice competencies, along the continuum of novice to expert can serve as the foundation for MLS curriculum and instructional design as well as measurement and evaluation in both formal and continuing education settings.

A typology of EBP research heuristics was defined relative to clinical laboratory science levels of practice. Research skills requisite for CLS baccalaureate level are associated mainly with quality control of analytic processes. Research skills at master's level are associated with pre-and post-analytic investigations, as well. Doctoral level CLS practice portends to utilize research skills facilitating quality investigations at the systems level.

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