Opportunities for Repeat Testing: Practice Doesn't Always Make Perfect

2005 ◽  
Author(s):  
Allison M. Geving ◽  
Shannon Webb ◽  
Bruce W. Davis
Keyword(s):  
Repeat Testing ◽  
Testing Practice

Analisa Pengujian Repeatability Timbangan Elektronik dengan Metode Syarat Teknis Timbangan Non Otomatis dan Metode NMI Australia

2019 ◽  
Vol 4 (2) ◽  
pp. 176-183
Author(s):  
Ponco Wali
Keyword(s):  
Research Method ◽  
Test Methods ◽  
Test Results ◽  
Repeat Testing ◽  
Testing Method ◽  
Technical Requirements

Testing repeat electronic scales with non-automatic scales technical requirements so far is fairly long if not using a calculator or computer. The aim of this research is to compare the repeatability testing method of electronic scales using methods according to the technical requirements of non-automatic scales and the Australian NMI method, both of which refer to OIML R76 in determining the validity or cancellation of electronic scales repeatability testing. This research method is done through repeat testing on 3 samples of electronic scales, then on each electronic scale 2 test methods are performed. The conclusion is that the electronic scales repeatability testing uses the non-automatic scales technical requirements method and the Australian NMI method has some differences although both refer to OIML R76. These differences include several points, namely the charge used, the method of adding additions, the formula for determining electronic scales, and different test results. The Australian NMI method is deemed to make it easier and more time efficient compared to the non-automatic weighing technical requirements method.

scholarly journals The Wild West of Emergency Use Authorizations for SARS-CoV-2 Testing: What Could Be the True Sensitivity?

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S142-S143
Author(s):  
S Dalal ◽  
S Patel ◽  
J M Petersen ◽  
D Jhala
Keyword(s):  
Medical Center ◽  
Initial Result ◽  
Reference Laboratory ◽  
Test Results ◽  
Rt Pcr ◽  
Repeat Testing ◽  
Parallel Testing ◽  
Percent Agreement ◽  
Instructions For Use ◽  
Multiple Reference

Abstract Introduction/Objective SARS-CoV-2 is a pandemic that has required mobilization to meet urgent needs. In this mobilization, emergency use authorizations (EUA) have been issued by the FDA to expedite the deployment of these tests. This has led to a situation whereby sensitivity has not been rigorously studied for any of the assays with EUAs. Estimates can be extrapolated from the limited samples documented by the company in their instructions for use (IFU). Although the nationwide shortage of testing reagents prevent parallel testing of multiple platforms on all specimens, observations of repeat specimens at the Veteran Affairs Medical Center (VAMC) provides the first study in the literature of more complete data for SARS-CoV-2 nucleic acid (RT-PCR) assay on sensitivity on the Abbott (Abbott Park Ill) and Cepheid (Sunnyvale CA) assays. Methods A retrospective search was performed for all test results for SARS-CoV-2 by RT-PCR from 3/1/2020 to 4/14/2020 at Corporal Michael J. Crescenz Medical Center, in order to evaluate the sensitivity on Abbott m2000 and Cepheid platforms. Results across multiple reference laboratories and in-house testing platforms were collated in a table with all patients clinically requiring repeat testing recorded. Results 114/863 patients had repeat testing. The tests were performed initially by outside reference laboratories (25 patients), on the Abbott m2000 (63 patients), and Cepheid Infinity (26 patients). 15/114 (13%) had discordant results on repeat testing. This included 1 test initially done by a reference laboratory. 8 days after the initial result from the reference lab, a positive for the same patient was identified on the Abbott platform. 11 initial Abbott results were discordant on further repeat testing on two platforms - Abbott (6 patients) and Cepheid (5 patients) 1-6 days later. In addition, 3 initial Cepheid were discordant on further repeat testing by the same Cepheid platform (1-16 days later). Conclusion While the instructions for use for both platforms suggest 100% sensitivity and specificity (due to the 100% positive and negative percent agreement in limited specimens), the true sensitivity is less than 100%, particularly early in the course of the infection. In our study, the positive percent agreement (surrogate for sensitivity) was 83% for initial Abbott tests, 88% for initial Cepheid tests, and 95% by Reference laboratory platform.

scholarly journals 458. Molecular SARS-CoV-2 Testing During the COVID-19 Outbreak: Experiences of a Hospital in Southeast Michigan, USA

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S296-S297
Author(s):  
Trini A Mathew ◽  
Jonathan Hopkins ◽  
Diane Kamerer ◽  
Shagufta N Ali ◽  
Daniel Ortiz ◽  
...  
Keyword(s):  
Clinical Features ◽  
Diagnostic Testing ◽  
Beaumont Hospital ◽  
High Capacity ◽  
Turnaround Time ◽  
Molecular Diagnostic ◽  
The Novel ◽  
Repeat Testing ◽  
Asymptomatic Patients ◽  
Novel Coronavirus

Abstract Background The novel Coronavirus SARS CoV-2 (COVID-19) outbreak was complicated by the lack of diagnostic testing kits. In early March 2020, leadership at Beaumont Hospital, Royal Oak Michigan (Beaumont) identified the need to develop high capacity testing modalities with appropriate sensitivity and specificity and rapid turnaround time. We describe the molecular diagnostic testing experience since initial rollout on March 16, 2020 at Beaumont, and results of repeat testing during the peak of the COVID-19 pandemic in MI. Methods Beaumont is an 1100 bed hospital in Southeast MI. In March, testing was initially performed with the EUA Luminex NxTAG CoV Extended Panel until March 28, 2020 when testing was converted to the EUA Cepheid Xpert Xpress SARS-CoV-2 for quicker turnaround times. Each assay was validated with a combination of patient samples and contrived specimens. Results During the initial week of testing there was > 20 % specimen positivity. As the prevalence grew the positivity rate reached 68% by the end of March (Figure 1). Many state and hospital initiatives were implemented during the outbreak, including social distancing and screening of asymptomatic patients to increase case-finding and prevent transmission. We also adopted a process for clinical review of symptomatic patients who initially tested negative for SARS-CoV-2 by a group of infectious disease physicians (Figure 2). This process was expanded to include other trained clinicians who were redeployed from other departments in the hospital. Repeat testing was performed to allow consideration of discontinuation of isolation precautions. During the surge of community cases from March 16 to April 30, 2020, we identified patients with negative PCR tests who subsequently had repeat testing based on clinical evaluation, with 7.1% (39/551) returning positive for SARS- CoV2. Of the patients who expired due to COVID-19 during this period, 4.3% (9/206) initially tested negative before ultimately testing positive. Figure 1 BH RO testing Epicurve Figure 2: Screening tool for repeat COVID19 testing and precautions Conclusion Many state and hospital initiatives helped us flatten the curve for COVID-19. Our hospital testing experience indicate that repeat testing may be warranted for those patients with clinical features suggestive of COVID-19. We will further analyze these cases and clinical features that prompted repeat testing. Disclosures All Authors: No reported disclosures

scholarly journals 528. Coronavirus Disease 2019 in Children Cared for at Texas Children’s Hospital: Implications of Repeat Testing on Infection Control Strategies

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S331-S332
Author(s):  
Catherine Foster ◽  
Lucila Marquez ◽  
Tjin Koy ◽  
Ila Singh ◽  
Judith Campbell
Keyword(s):  
Infection Control ◽  
Median Time ◽  
Disease Transmission ◽  
Retrospective Chart Review ◽  
Source Control ◽  
Hospitalized Children ◽  
Rt Pcr ◽  
Repeat Testing ◽  
Children's Hospital ◽  
Children’S Hospital

Abstract Background Accurate diagnosis of coronavirus disease 2019 (COVID-19) is key for source control and interrupting disease transmission. To better understand the length of viral shedding in children and potential infection control implications, we describe 51 children with COVID-19 who underwent repeat testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at Texas Children’s Hospital (TCH). Methods We performed a retrospective chart review of all pediatric patients (< 21 years of age) with ≥ 2 nasopharyngeal specimens tested for SARS-CoV-2 by reverse transcription-polymerase chain reaction (rt-PCR) and at least one positive result between 3/13/2020 and 6/7/2020 through the TCH Molecular Microbiology Laboratory. Results Fifty-one patients met inclusion criteria. The median age was 8.6 years (0.02–19.2 years). Sixteen (31%) children were hospitalized. Fourteen (27%) patients underwent testing for surveillance purposes (including 3 admitted patients). Two SARS-CoV-2 tests were performed in 25 (49%) children; while 12 (24%) children had 3 tests, 4 (8%) children had 4 tests, and 10 (20%) children had ≥ 5 tests (including 1 patient with underlying malignancy who had 9 SARS-CoV-2 PCRs performed). SARS-CoV-2 testing timeline for 9 hospitalized children is shown (Fig 1). The median time between collection of tests 1 and 2 was 14 days (n=51, range 1, 53 days). For children with conversion (first detected to first not-detected sample), the median time was 15 days (n=31, range 1, 45 days). For patients with consecutive positive SARS-CoV-2 PCRs, the median time of positivity was 10 days (n=19, range 2, 31). One patient with malignancy had 5 tests over 6 weeks in the outpatient setting and each time alternated between detected and not-detected. Following diagnosis with COVID-19, one patient with sickle cell disease likely had re-infection and had a positive test after having 2 consecutive negative tests; his last SARS-CoV-2 rt-PCR was positive 68 days after initial positive. Fig 1. Timing of Repeat SARS-CoV-2 PCRs in Select Hospitalized Children with COVID-19 Conclusion We observed variation in the duration of SARS-CoV-2 rt-PCR positivity in children with COVID-19. For children with COVID-19, a single negative molecular assay for SARS-CoV-2 may not be predictive of sustained negativity. Disclosures All Authors: No reported disclosures

scholarly journals 421. If at first you do not succeed…. Repeat SARS-COV2 PCR testing

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S277-S278
Author(s):  
Stephanie M Shea ◽  
Gopi Patel ◽  
Sarah Schaefer ◽  
Michael D Nowak ◽  
Emilia Mia Sordillo ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Patient Characteristics ◽  
Nucleic Acid Amplification ◽  
Duration Of Symptoms ◽  
Radiographic Findings ◽  
Repeat Testing ◽  
Clinical Sensitivity ◽  
Viral Transport Medium ◽  
Minimum Interval ◽  
Roche Diagnostics

Abstract Background Nucleic Acid Amplification Tests (NAATs) of nasopharyngeal specimens (NPS) have become standard for diagnosis of SARS-COV2. IDSA guidelines suggest repeat testing after 24–48 h when initially negative and clinical suspicion persists. We characterized patients from whom initial NPS were NAAT-negative, but repeats were NAAT-positive, in order to identify which patients might benefit from repeat NAAT for SARS-CoV-2, and the appropriate interval. Methods We conducted an IRB-approved retrospective review of laboratory and electronic medical record data for all patients evaluated for SARS-CoV-2 infection at the Mount Sinai Health System, whose initial NAATs were done between March 16 – March 30, 2020, and who were retested within one month. NAATs were performed on NPS in viral transport medium using the Roche Diagnostics cobas® 6800 SARS-CoV-2 Test. Baseline patient characteristics, clinical and radiographic findings were identified. Results Of 235 patients eligible for inclusion, 172 (70.5%) were initially NAAT-negative, and 118 (68.6%) remained NAAT-negative over 1 month follow up. 54 (31.4%) converted to NAAT-positive over the next 1-month. Of patients who became NAAT-positive, 31 (57.4%) were inpatients who converted results within a single admission; the average interval was 6d 7h between the NAAT-negative and NAAT-positive results, and the minimum interval was 10.5 h. Symptoms examined for correlation for conversion to NAAT-positive were: fever, cough, shortness of breath, and combined nausea/vomiting/diarrhea. Duration of symptoms reported at triage did not appear to affect time to conversion to NAAT-positive. No individual symptom was more likely to be associated with conversion to NAAT- positive. However, time to conversion to NAAT-positive was shorter for patients with multiple symptoms. In general, chest radiography (CXR) findings correlated with NAAT results; interval to NAAT-positive was shorter for patients with worsening CXR findings. Conclusion Our data supports repeat testing in patients with multiple clinical symptoms suggestive of SARS CoV-2 infection and negative initial NP test results. Further studies are needed to determine the true clinical sensitivity and specificity of SARS-CoV-2 NAAT assays. Disclosures All Authors: No reported disclosures

Recent HIV-1 Infection Detection: Comparison of Incidence Estimates Derived by Laboratory Assays and Repeat Testing Data

2009 ◽  
Vol 51 (4) ◽  
pp. 502-505 ◽  
Author(s):  
Hong-Ha M Truong ◽  
Timothy Kellogg ◽  
Brian Louie ◽  
Jeffrey Klausner ◽  
James Dilley ◽  
...  
Keyword(s):  
Repeat Testing ◽  
Infection Detection ◽  
Testing Data ◽  
Hiv 1

scholarly journals Coronavirus Disease 2019 Serial Testing Among Hospitalized Patients in a Midwest Tertiary Medical Center, July–September 2020

2020 ◽  
Author(s):  
Takaaki Kobayashi ◽  
Alexandra Trannel ◽  
Stephanie A Holley ◽  
Mohammed A Alsuhaibani ◽  
Oluchi J Abosi ◽  
...  
Keyword(s):  
Incubation Period ◽  
Conversion Rate ◽  
Medical Center ◽  
Hospitalized Patients ◽  
Repeat Testing ◽  
Negative Test ◽  
Serial Testing

Abstract We implemented serial coronavirus disease 2019 testing for inpatients with a negative test on admission. The conversion rate (negative to positive) on repeat testing was 1%. We identified patients during their incubation period and hospital-onset cases, rapidly isolated them, and potentially reduced exposures. Serial testing and infectiousness determination were resource intensive.

A Practical Approach to Pediatric Patients Referred With an Abnormal Coagulation Profile

2005 ◽  
Vol 129 (8) ◽  
pp. 1011-1016 ◽  
Author(s):  
Monica Acosta ◽  
Rachel Edwards ◽  
E. Ian Jaffe ◽  
Donald L. Yee ◽  
Donald H. Mahoney ◽  
...  
Keyword(s):  
Family History ◽  
Positive Family History ◽  
Laboratory Data ◽  
Bleeding Risk ◽  
Personal History ◽  
Retrospective Case ◽  
Laboratory Assessment ◽  
Repeat Testing ◽  
Effective Manner ◽  
History Of

Abstract Context.—Workup for prolonged prothrombin time (PT) and activated partial thromboplastin time (PTT) is a frequent referral to a Hematology and Coagulation Laboratory. Although the workup should be performed in a timely and cost-effective manner, the complete laboratory assessment of the coagulation state has not been standardized. Objective.—To determine which clinical and laboratory data are most predictive of a coagulopathy and to formulate the most efficient strategy to reach a diagnosis in patients referred for abnormal coagulation profiles. Design.—Retrospective case review. Medical records of 251 patients referred for prolonged PT and/or PTT to our Hematology Service between June 1995 and December 2002 were reviewed. Results.—The study included 135 males and 116 females with a mean age of 7.0 years. A personal history of bleeding was reported in 137 patients, and a family history of bleeding was reported in 116 patients. Fifty-one patients (20%) had a coagulopathy (ie, a bleeding risk). Factors predictive of a bleeding risk were a positive family history of bleeding (P < .001) and a positive personal history of bleeding (P = .001). Of 170 patients with findings of normal PT and PTT values on repeat testing, 14 were subsequently diagnosed with a coagulopathy. Two of these patients reported no positive personal or family history of bleeding. Conclusions.—Coagulopathy was identified in 20% of the children referred for abnormal PT and/or PTT. In the absence of a personal or family history of bleeding, a normal PT and/or PTT on repeat testing has a negative predictive value of more than 95%.

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