Citations

Abstract Context.—Unnecessary tests, inefficient ordering practices, and collection of more blood than is required for testing contribute to iatrogenic anemia in hospitalized patients. Laboratories accredited by the College of American Pathologists are expected to review phlebotomy practices for specimen collection volumes periodically. Objective.—To report specimen collection, analytic, and discard volumes for routine laboratory tests and to identify practice variables associated with overcollection and blood wastage. Design.—Clinical laboratories participating in the College of American Pathologists Q-Probes laboratory improvement program recorded collection container size, laboratory-defined requested volume, manufacturer-defined analytic volume, and average discard volume for routine complete blood cell counts and electrolyte panels ordered for patients in intensive care units. Participants provided information about their specimen collection, processing, and analytic practices in a questionnaire. Setting and Participants.—A total of 140 public and private institutions. Main Outcome Measures.—Overcollections for routine collections and for situations in which a reduced volume of specimen is collected, and average discard volume per tube. Results.—Laboratories collected a median of 2.76 mL (or 8.5 times) more than their instrument's analytic volume for routine complete blood cell counts and 1.75 mL (or 12 times) more than their instrument's analytic volume for routine electrolyte panels. For clinical situations in which reduced collection volumes were necessary, overcollection for the same analytes was 0.5 mL (3 times) and 0.44 mL (4.2 times), respectively. The median discard volume was 2.8 mL/tube for complete blood cell counts and 2.0 mL/tube for electrolyte panels. Specimen collection container size was directly associated with overcollections and discard volumes. Instrument analytic volume was not a determinant of blood wastage. Conclusions.—Most laboratories can decrease collection volumes without compromising the ability of the laboratory to report a reliable and timely result. Use of smaller collection tubes can help reduce blood wastage.

Abstract Objectives.—To determine the rate with which blood collection is successful on the initial phlebotomy encounter, the rate with which laboratory personnel judge specimens unsuitable for analysis, and the practice characteristics associated with fewer unsuccessful collections and fewer rejected specimens. Design.—Clinical laboratories participating in the College of American Pathologists Q-Probes laboratory improvement program prospectively characterized the outcome of outpatient phlebotomies for 3 months or until 20 unsuccessful phlebotomy encounters occurred. By questionnaire, participants provided information about test ordering, patient preparation, and specimen collection. Setting and Participants.—Institutions in the United States (n = 202), Canada (n = 4), Australia (n = 3), and South Korea (n = 1). Main Outcome Measures.—Percentage of successful encounters and percentage of unsuitable specimens. Results.—Of 833289 encounters, 829723 were successful. Phlebotomies were unsuccessful because patients were not fasting as directed (32.2%), phlebotomy orders were missing information (22.5%), patients specimens were difficult to draw (13.0%), patients left the collection area before specimens were collected (11.8%), patients were improperly prepared for reasons other than fasting (6.3%), patients presented at the wrong time (3.1%), or for other reasons (11.8%). Only 2153 specimens (0.3%) were unsuitable; these samples were hemolyzed (18.1%), of insufficient quantity (16.0%), clotted (13.4%), lost or not received in the laboratory (11.5%), inadequately labeled (5.8%), at variance with previous or expected results (4.8%), or unacceptable for other reasons (31.1%). Facilities staffed by laboratory-administered phlebotomists reported higher success rates than facilities staffed by nonlaboratory-administered phlebotomists (P = .002). Conclusions.—Most outpatient phlebotomy encounters are successful and result in specimens suitable for laboratory analysis.

Abstract Context.—Laboratory diagnosis of group A streptococcal pharyngitis in physician office and small-hospital laboratories. Objective.—To characterize laboratory practices for the diagnosis of group A streptococcal pharyngitis and to identify opportunities for improvement. Design.—Voluntary self-assessment questionnaire, used to assess the laboratory practices of 790 laboratories subscribing to the College of American Pathologists Excel Microbiology Proficiency Testing Program. Results.—We observed discrepancies between self-reported and recommended specimen collection and laboratory testing practices for some laboratories. The most notable discrepancies were failing to provide a written specimen-collection procedure (17.8%), sampling the tongue and oral mucosa (2%), failing to always perform back-up cultures when rapid antigen test results were negative (57.5%), and finalizing culture reports within 24 hours or less (34.0%). Additionally, among those respondents who used the bacitracin disk, 57.9% (277 respondents) applied the disk directly onto a primary plate. Conclusions.—Opportunities exist to improve testing practices for the diagnosis of group A streptococcal pharyngitis for some physician office and small-hospital laboratories.

Abstract Objectives.—To establish the rates with which reference laboratories resolve inquiries telephoned to them from primary laboratories and to identify reference laboratory practices associated with higher rates of inquiry resolution. Design and Participants.—For 2 months, or until 50 contacts had occurred, 545 primary laboratories participating in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively documented and characterized telephone inquiries they made to a reference laboratory of their choice. Participants also cataloged their own laboratory's demographic and practice characteristics and their reference laboratory's customer service characteristics. Main Outcome Measure.—Rates with which reference laboratories resolved telephone inquiries. Results.—Participants characterized 11 031 (78.7%) of 14 017 telephone inquiries as resolved by the reference laboratories. Ranked according to inquiry resolution rates, primary laboratories in the 90th percentile characterized reference laboratories as resolving 100% of their inquiries; those in the 10th percentile characterized reference laboratories as resolving only 54.2% of their inquiries. The rate of resolved inquiries was significantly higher (P = .0047) for participants using reference laboratories with 24-hour customer service than it was for participants using reference laboratories with less than 24-hour service. Most primary laboratories (80.9%) chose to monitor 1 of 11 national reference laboratories; in this subset, median rates of inquiry resolution ranged from 90.2% to 55.0% (P < .0001), despite no significant variation in other measured customer service characteristics. Conclusions.—Primary laboratories experience significant differences in the rates with which reference laboratories resolve telephone inquiries. The performance benchmark for reference laboratories is resolution of at least 90% of telephone inquiries from primary laboratory customers.

Abstract Objective. —To determine the frequency with which solitary blood culture samples were submitted to laboratories serving small hospitals and to ascertain whether certain hospital practices relating to the performance of blood cultures were associated with lower solitary blood culture rates (SBCRs). Design. —Participants in the College of American Pathologists Q-Probes laboratory quality improvement program collected data prospectively on the numbers of solitary blood culture sets from adult patients submitted to their laboratories and answered questions about their institutions' practice characteristics relating to the collection of blood culture specimens. Setting and Participants. —Three hundred thirty-three public and private institutions with a median occupied bed size of 57. Participants were located in the United States (n = 329), Canada (n = 3), and Australia (n = 1). Main Outcome Measure. —The solitary blood culture rate was defined as the number of instances in which only 1 blood culture venipuncture was performed on an individual patient during a 24-hour period divided by the total number of blood culture venipunctures that were performed during the study period. Results. —Participants submitted data on 132 778 adult patient blood culture sets. The SBCRs were 3.4% or less in the top-performing 10% of participating institutions (90th percentile and above), 12.7% in the midrange of participating institutions (50th percentile), and 42.5% or more in the bottom-performing 10% of participating institutions (10th percentile and below). In half the participating institutions, the SBCRs for inpatients were 8.3% or less and for outpatients, 22% or less. Solitary blood culture rates were lower for institutions in which phlebotomists rather than nonphlebotomists routinely collected blood culture specimens, in which internal policies required drawing at least 2 blood culture sets, in which hospital personnel contacted clinicians when their laboratories received requests for solitary blood culture sets, and in which quality control programs monitored SBCRs routinely. Conclusions. —Hospitals can achieve SBCRs under 5%. Those hospitals with particularly high SBCRs may lower their rates by altering certain institutional practices.

Abstract Objectives. —To determine the success with which laboratories were able to report morning test results on time, the laboratory practice characteristics associated with improved success, and the degree of satisfaction among clinicians with the timeliness of laboratory service. Design. —Hospital laboratories participating in the College of American Pathologist Q-Probes laboratory quality improvement program prospectively calculated the percentages of morning-run complete blood cell count (CBC) and electrolyte results that were reported on or before predetermined reporting deadlines, completed questionnaires concerning their departments' practice characteristics as they related to performing morning blood work, and distributed to physician utilizers of morning laboratory services questionnaires evaluating physician satisfaction with laboratory services. Setting and Participants. —A total of 367 public and private institutions located in the United States (355), Canada (5), Australia (2), and 1 each in the United Kingdom, Spain, Brazil, Korea, and Guam. Main Outcome Measure. —The percentages of morning-run CBC and electrolyte results reported on or before predetermined reporting deadlines. Results. —Participants submitted data on 40 256 CBC and 39 604 electrolyte specimens. In aggregate, a total of 88.9% of these tests (90.2% of CBCs and 87.6% of electrolytes) were reported on or before the reporting deadlines that the participating laboratories set for themselves. Half of the participants reported 94.6% of their CBC results and 95.5% of their electrolyte results on or before their self-imposed reporting deadlines. No specific demographic features or departmental practice characteristics were associated with higher or lower rates of institutional reporting compliance. Most physician utilizers of early-morning laboratory test results believed that the laboratory is sensitive to and meets the needs of clinicians for timely reporting of early-morning test results. Conclusions. —Most laboratories are capable of reporting 95% of their routine morning laboratory tests on time, and most physicians are satisfied with their laboratories' morning testing service.

Abstract Objective. —To characterize laboratory practices for neonatal bilirubin testing and to identify opportunities for improvement. Design. —A voluntary self-assessment questionnaire was used to assess the laboratory practices of 312 laboratories subscribing to the College of American Pathologists (CAP) Excel Chemistry Proficiency Testing Program. Results. —A range of preanalytic and analytic practices were reported. The most notable problems identified were the use of overly long capillary puncture devices (17.8%), failure to protect the specimen from light prior to analysis (3.4%), failure to use a control containing >171 μmol/L bilirubin (26.1%), use of single-level control (4.2%), and lack of established linearity limits (7.0%). Conclusion. —Opportunities exist to improve specimen collection, processing, and analysis for some physician-office and small-hospital laboratories.

Abstract Triggering receptor expressed on myeloid cell 2 (TREM2) is a surface receptor that, in the central nervous system, is exclusively expressed on microglia. TREM2 variants have been linked to increased risk for neurodegenerative diseases, but the functional effects of microglial TREM2 remain largely unknown. To this end, we investigated TAR-DNA binding protein 43 kDa (TDP-43)-related neurodegenerative disease via viral-mediated expression of human TDP-43 protein (hTDP-43) in mice or inducible expression of hTDP43 with defective nuclear localization signals in transgenic mice. We found that TREM2 deficiency impaired microglia phagocytic clearance of pathological TDP-43, and enhanced neuronal damage and motor function impairments. Mass cytometry analysis revealed that hTDP-43 induced a TREM2-dependent subpopulation of microglia with high CD11c expression and higher phagocytic ability. Using mass spectrometry, we further demonstrated an interaction between TDP-43 and TREM2, in vitro and in vivo, in hTDP-43-expressing transgenic mouse brains. We computationally identified the region within hTDP-43 that interacts with TREM2 and observed the potential interaction in ALS patient tissues. Our data reveal the novel interaction between TREM2 and TDP-43, highlighting that TDP-43 is a potential ligand for microglial TREM2 and the interaction mediates neuroprotection of microglial TREM2 in TDP-43-related neurodegeneration.