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2.
BMC Infect Dis ; 19(1): 1017, 2019 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-31791265

RESUMEN

BACKGROUND: Early diagnosis and treatment of neurosyphilis is of great significance for regression. There is no gold standard for the diagnosis of neurosyphilis. We did this study to explore the factors associated with the clinical diagnosis of neurosyphilis and assess their accuracy for the diagnosis of neurosyphilis. METHODS: We retrospectively reviewed 100 cases of syphilis patients who underwent lumbar puncture at a major dermatology hospital in Guangzhou, China between April 2013 and November 2016. Fifty patients who were clinically diagnosed with neurosyphilis were selected as case group. Control group consisted of 50 general syphilis patients who were matched with age and gender. The records of patients were reviewed to collect data of socio-demographic information, clinical symptom, and laboratory indicators. Multivariable logistic regression was used to explore diagnostic indictors, and ROC analysis was used to assess diagnostic accuracy. RESULTS: Neurological symptoms (odds ratio (OR) = 59.281, 95% CI:5.215-662.910, P = 0.001), cerebrospinal fluid (CSF) Treponema pallidum particle agglutination (TPPA) titer (OR = 1.004, 95% CI:1.002-1.006, P < 0.001), CSF protein (OR = 1.005, 95% CI:1.000-1.009, P = 0.041), and CSF white blood cell (WBC) (OR = 1.120, 95% CI:1.017-1.233, P = 0.021) were found to be statistically associated with neurosyphilis. In ROC analysis, CSF TPPA titer had a sensitivity of 90%, a specificity of 84%, and an area under curve (AUC) of 0.941. CONCLUSION: CSF TPPA can potentially be considered as an alternative test for diagnosis of neurosyphilis. Combining with neurological symptoms, CSF protein, CSF WBC, the diagnosis would have a higher sensitivity.


Asunto(s)
Seronegatividad para VIH , Neurosífilis/diagnóstico , Adulto , Estudios de Casos y Controles , China/epidemiología , Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/normas , Femenino , Infecciones por VIH/líquido cefalorraquídeo , Infecciones por VIH/complicaciones , Infecciones por VIH/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Neurosífilis/líquido cefalorraquídeo , Neurosífilis/complicaciones , Neurosífilis/epidemiología , Valor Predictivo de las Pruebas , Pronóstico , Estudios Retrospectivos , Sensibilidad y Especificidad , Sífilis/líquido cefalorraquídeo , Sífilis/complicaciones , Sífilis/diagnóstico , Sífilis/epidemiología , Treponema pallidum
3.
PLoS Negl Trop Dis ; 13(12): e0007884, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31877142

RESUMEN

Hantavirus Pulmonary Syndrome is an, often fatal, emerging zoonotic disease in the Americas caused by hantaviruses (family: Hantaviridae). In Brazil, hantavirus routine diagnosis is based on serology (IgM-ELISA) while RT-PCR is often used to confirm acute infection. A Semi-nested RT-PCR and an internally controlled RT-qPCR assays were developed for detection and quantification of four hantaviruses strains circulating in the Brazilian Amazon: Anajatuba (ANAJV) and Castelo dos Sonhos (CASV) strains of Andes virus (ANDV) species; and Rio Mamoré (RIOMV) and Laguna Negra (LNV) strains of LNV species. A consensus region in the N gene of these hantaviruses was used to design the primer sets and a hydrolysis probe. In vitro transcribed RNA was diluted in standards with known concentration. MS2 bacteriophage RNA was detected together with hantavirus RNA as an exogenous control in a duplex reaction. RT-qPCR efficiency was around 100% and the limit of detection was 0.9 copies/µL of RNA for RT-qPCR and 10 copies/µL of RNA for Semi-nested RT-PCR. There was no amplification of either negative samples or samples positive to other pathogens. To assess the protocol for clinical sensitivity, specificity and general accuracy values, both assays were used to test two groups of samples: one comprising patients with disease (n = 50) and other containing samples from healthy individuals (n = 50), according to IgM-ELISA results. A third group of samples (n = 27) infected with other pathogens were tested for specificity analysis. RT-qPCR was more sensitive than semi-nested RT-PCR, being able to detect three samples undetected by conventional RT-PCR. RT-qPCR clinical sensitivity, specificity and general accuracy values were 92.5%, 100% and 97.63%, respectively. Thus, the assays developed in this study were able to detect the four Brazilian Amazon hantaviruses with good specificity and sensitivity, and may become powerful tools in diagnostic, surveillance and research applications of these and possibly other hantaviruses.


Asunto(s)
Pruebas Diagnósticas de Rutina/métodos , Síndrome Pulmonar por Hantavirus/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Adulto , Brasil , Pruebas Diagnósticas de Rutina/normas , Hantavirus/clasificación , Hantavirus/aislamiento & purificación , Humanos , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/normas , Reacción en Cadena en Tiempo Real de la Polimerasa/normas , Estándares de Referencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/normas , Sensibilidad y Especificidad , Adulto Joven
4.
Public Health Rep ; 134(2_suppl): 53S-57S, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31682562

RESUMEN

This study describes the efforts and outcomes associated with the establishment of a clinical sample repository during the 2016 Zika virus epidemic. To overcome the challenge of limited access to clinical samples to support diagnostic test development, multiple US Department of Health and Human Services (HHS) agencies formed a partnership to create the HHS Zika Specimen Repository. In 2016-2017, the Biomedical Advanced Research and Development Authority and the Centers for Disease Control and Prevention collected patient specimens (4420 convalescent sera aliquots from 100 donors and 7171 plasma aliquots from 239 donors), confirmed Zika virus test results, assembled 1 panel for molecular testing (n = 25 sets) and 7 panels for serologic testing (n = 92), and distributed the panels to test developers. We manufactured 8 test panels and distributed 74 sets of panels to 32 commercial companies, public health partners, and research institutions. Manufacturers used these panels to generate data that supported 14 US Food and Drug Administration (FDA) emergency use authorizations and 1 FDA approval. To develop a repository that can respond immediately to future disease outbreaks, we recommend that organizations pre-position procedures, resources, and partnerships to optimize each partner's contribution.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Brotes de Enfermedades/estadística & datos numéricos , Salud Pública/normas , Asociación entre el Sector Público-Privado/tendencias , United States Dept. of Health and Human Services/tendencias , Infección por el Virus Zika/epidemiología , Virus Zika/aislamiento & purificación , Brotes de Enfermedades/prevención & control , Humanos , Estados Unidos , Virus Zika/genética , Infección por el Virus Zika/sangre
5.
Vet Microbiol ; 239: 108452, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31767099

RESUMEN

Bovine viral diarrhea (BVD), one of the most important infectious diseases in cattle, causes major economic losses and significant impact on animal welfare worldwide. The major source for virus spread is persistently infected, immunotolerant calves and, therefore, their early identification is of utmost importance for disease prevention. Here, a ring trial was initiated to control the performance of diagnostic tests used in German regional laboratories in charge of the diagnostics within the country's BVD control program. A panel of five ear notch and five serum samples was provided for virological analysis. By an antigen ELISA, which was applied 26 times, the status of every sample was correctly identified in any case. In addition, a total of 54 real-time RT-PCR result sets was generated and also in most cases correctly classified. In addition to the virological test panel, a set of six sera and four milk samples was sent to the participating laboratories to be analyzed by serological methods. With serum neutralization tests, an excellent diagnostic sensitivity was achieved. However, one serum and both milk samples - positive for BVDV antibodies - repeatedly tested false negative by some of the used ELISA kits. All negative serum and milk samples were correctly identified by every commercial antibody ELISA. In conclusion, the BVDV proficiency test demonstrated that the used antigen/genome test systems allowed predominantly reliable diagnostics, while for four of the applied nine antibody ELISA kits adjustments are recommended.


Asunto(s)
Diarrea Mucosa Bovina Viral/diagnóstico , Pruebas Diagnósticas de Rutina/veterinaria , Animales , Anticuerpos Antivirales/análisis , Anticuerpos Antivirales/sangre , Diarrea Mucosa Bovina Viral/inmunología , Bovinos , Pruebas Diagnósticas de Rutina/normas , Virus de la Diarrea Viral Bovina/inmunología , Erradicación de la Enfermedad , Ensayo de Inmunoadsorción Enzimática/normas , Ensayo de Inmunoadsorción Enzimática/veterinaria , Alemania , Leche , Reacción en Cadena en Tiempo Real de la Polimerasa/normas , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Sensibilidad y Especificidad
6.
J Fish Dis ; 42(11): 1471-1491, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31637760

RESUMEN

Samples from multiple animals may be pooled and tested to reduce costs of surveillance for infectious agents in aquatic animal populations. The primary advantage of pooling is increased population-level coverage when prevalence is low (<10%) and the number of tests is fixed, because of increased likelihood of including target analyte from at least one infected animal in a tested pool. Important questions and a priori design considerations need to be addressed. Unfortunately, pooling recommendations in disease-specific chapters of the 2018 OIE Aquatic Manual are incomplete and, except for amphibian chytrid fungus, are not supported by peer-reviewed research. A systematic review identified only 12 peer-reviewed aquatic diagnostic accuracy and surveillance studies using pooled samples. No clear patterns for pooling methods and characteristics were evident across reviewed studies, although most authors agreed there is a negative effect on detection. Therefore, our purpose was to review pooling procedures used in published aquatic infectious disease research, present evidence-based guidelines, and provide simulated data examples for white spot syndrome virus in shrimp. A decision tree of pooling guidelines was developed for use by peer-reviewed journals and research institutions for the design, statistical analysis and reporting of comparative accuracy studies of individual and pooled tests for surveillance purposes.


Asunto(s)
Crustáceos/virología , Pruebas Diagnósticas de Rutina/normas , Monitoreo Epidemiológico/veterinaria , Enfermedades de los Peces/epidemiología , Guías como Asunto , Virus del Síndrome de la Mancha Blanca 1/fisiología , Animales , Enfermedades Transmisibles/epidemiología , Enfermedades Transmisibles/veterinaria , Vigilancia de la Población/métodos , Prevalencia
7.
PLoS Negl Trop Dis ; 13(10): e0007773, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31658252

RESUMEN

In 2012, the U.S. Defense Threat Reduction Agency Joint Science and Technology Office initiated a program to develop novel point-of-need diagnostic devices for surveillance of emerging infectious diseases including dengue, malaria, plague, and melioidosis. Prior to distribution of devices to observe their correct use among community members in Iquitos, Peru, and Phnom Penh, Cambodia, research was conducted to: 1) assess acceptability of use, including the motivation to use a rapid diagnostic test (RDT) before or instead of seeking care at a health facility, 2) explore comprehension of RDT use instructions, and 3) examine possible strategies for large scale RDT distribution and use at each site. In February 2014, 9 focus group discussions (FGD) with community members and 5 FGD with health professionals were conducted in Iquitos, and 9 FGD with community members and 9 in-depth interviews with health professionals in Phnom Penh. In both places, participants agreed to use the device themselves (involving finger prick) or could identify someone who could do so in their home or neighborhood. The main incentive to RDT use in both sites was the ability for device results to be used for care facilitation (post confirmatory tests), specifically reduced wait times to be seen or obtain a diagnosis. Comprehension of RDT use instructions was assessed in Iquitos by asking some participants to apply the device to research team members; after watching a short video, most steps were done correctly. In Phnom Penh, participants were asked to describe each step after reading the instructions; they struggled with comprehension. Health professionals' main concerns in both sites were their community's ability to accurately use the test, handle complicated instructions, and safety (i.e., disposal of lancets). Health system structure and ability to use home diagnostic devices varied in the two disease endemic sites, with substantial challenges in each, suggesting the need for different strategies for RDT large scale community use, and illustrating the value of formative research before deployment of novel technologies.


Asunto(s)
Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/normas , Personal de Salud/educación , Adolescente , Adulto , Cambodia , Dengue/diagnóstico , Educación/métodos , Femenino , Grupos Focales , Instituciones de Salud , Conocimientos, Actitudes y Práctica en Salud , Investigación sobre Servicios de Salud , Humanos , Malaria/diagnóstico , Masculino , Melioidosis/diagnóstico , Persona de Mediana Edad , Aceptación de la Atención de Salud , Perú , Peste/diagnóstico , Manejo de Especímenes/métodos , Adulto Joven
9.
Acta Trop ; 199: 105118, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31369728

RESUMEN

Well-defined diagnostic gold standards are rarely available for the diagnosis of rare diseases such as some tropical infections. Algorithms for reliable test evaluation without gold standard are therefore desirable. On the basis of previous work of Gart and Buck (1966); Rogan and Gladen (1978), and Hui and Walter (1980), a modeling approach for the comparison of diagnostic tests without a gold standard - and thus without reliably characterized reference sample material - is established especially for situations not fulfilling the requirement of conditional independence of the diagnostic tests evaluated. In the approach introduced, each test is conducted within two populations with different values of prevalence and the test results are used to define two virtual reference tests. The model is useful for the comparison of tests for rare tropical diseases where no gold standard can be provided.


Asunto(s)
Infecciones por Actinomycetales/diagnóstico , Pruebas Diagnósticas de Rutina/normas , Enfermedades Raras/diagnóstico , Tropheryma/aislamiento & purificación , Algoritmos , Pruebas Diagnósticas de Rutina/métodos , Humanos , Modelos Teóricos , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/normas , Prevalencia , Sensibilidad y Especificidad , Tropheryma/genética , Clima Tropical
10.
Eur J Endocrinol ; 181(4): 421-428, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31376812

RESUMEN

Objective: Saline infusion test (SIT) and captopril challenge test (CCT) are standard confirmatory procedures routinely used in the diagnostic work-up of primary aldosteronism (PA). However, side effects and complications during testing have not been systematically studied. Design: We performed a cohort study with patients undergoing SIT and/or CCT in two centers from 2016 until 2018. Methods: We studied 272 study participants with suspected PA enrolled at two outpatient centers in Germany. We assessed the frequency and severity of side effects during adjustment of blood pressure medication and during SIT and CCT. Results: During the adjustment phase prior confirmatory testing, side effects including palpitations, headaches, edema and hypertensive episodes occurred in 18.4% of study participants. Side effects were associated with higher defined daily doses (DDD) (r = 0.25, P < 0.005), number of antihypertensive drugs (r = 0.285, P < 0.005) and higher blood pressure (r = 0.145, P = 0.019). During SIT, 17.5% of study participants had side effects, associated with higher blood pressure (systolic: r = 0.541, P < 0.0005; diastolic: r = 0.426, P < 0.0005) and DDDs (r = 0.727, P < 0.0005). During CCT, only 1.5% of study participants developed side effects. Conclusions: In contrast to the high rate of side effects during SIT, CCT appears to be the safer test with a very low event rate. This makes CCT especially suitable for severely hypertensive patients.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Hiperaldosteronismo/sangre , Hiperaldosteronismo/diagnóstico , Seguridad del Paciente/normas , Adulto , Estudios de Cohortes , Pruebas Diagnósticas de Rutina/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad
11.
Surg Infect (Larchmt) ; 20(7): 530-534, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31464572

RESUMEN

Background: A landscape analysis of mobile health (mHealth) applications and published literature related to their use in surgical site infection (SSI) detection and surveillance was conducted by the Assessing Surgical Site Infection Surveillance Technologies (ASSIST) investigators. Methods: The literature review focused on post-discharge SSI detection or tracking by caregivers or patients using mHealth technology. This report is unique in its review across both commercial and research-based mHealth apps. Apps designed for long-term wound tracking and those focused on care coordination and scheduling were excluded. A structured evaluation framework was used to assess the operational, technical, and policy features of the apps. Results: Of the 10 apps evaluated, only two were in full clinical use. A variety of data were captured by the apps including wound photographs (eight apps), wound measurements (three apps), dressing assessments (two apps), physical activity metrics (three apps), medication adherence (three apps) as well as structured surveys, signs, and symptoms. Free-text responses were permitted by at least two apps. The extent of integration with the native electronic health record system was variable. Conclusion: The examination of rapidly evolving technologies is challenged by lack of standard evaluative methods, such as those more commonly used in clinical research. This review is unique in its application of a structured evaluation framework across both commercial and research-based mHealth apps.


Asunto(s)
Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/normas , Monitoreo Epidemiológico , Infección de la Herida Quirúrgica/diagnóstico por imagen , Telemedicina/métodos , Humanos , Procesamiento de Imagen Asistida por Computador , Datos de Salud Generados por el Paciente , Periodo Posoperatorio
12.
Diagn Microbiol Infect Dis ; 95(3): 114841, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31422873

RESUMEN

OBJECTIVES: To compare the performance and time-to-result (TTR) for antimicrobial susceptibility testing (AST) of positive blood cultures (PBC) using the Accelerate Pheno™ system (AXDX) and both a direct VITEK® 2 card inoculation workflow (DV2) and traditional FDA-approved VITEK® 2 workflow using subcultured isolates (V2). METHODS: Patient samples with monomicrobial Gram-negative rod bacteremia were tested on AXDX and DV2 in tandem and compared to V2 AST results. Categorical agreement (CA) errors were adjudicated using broth microdilution. Instrumentation times and AST TTR were compared. RESULTS: AXDX and DV2 had a CA of 93.4% and 97.4%, respectively, compared to V2. Postadjudication, AXDX, DV2, and V2 had CA of 94.7%, 95.7%, and 96.5%, respectively. Instrument run times were 6.6 h, 9.4 h, and 9.2 h, and AST TTR were 8.9 h, 12.9 h and 35.5 h, respectively. CONCLUSIONS: AXDX and DV2 ASTs are fast and reliable, which may have significant antimicrobial stewardship implications.


Asunto(s)
Cultivo de Sangre , Pruebas Diagnósticas de Rutina/métodos , Pruebas de Sensibilidad Microbiana/métodos , Programas de Optimización del Uso de los Antimicrobianos , Bacteriemia/microbiología , Pruebas Diagnósticas de Rutina/instrumentación , Pruebas Diagnósticas de Rutina/normas , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Gramnegativas/metabolismo , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Pruebas de Sensibilidad Microbiana/instrumentación , Pruebas de Sensibilidad Microbiana/normas , Estudios Prospectivos , Factores de Tiempo , Flujo de Trabajo , beta-Lactamasas/biosíntesis
13.
Int J Lab Hematol ; 41(5): 642-649, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31271498

RESUMEN

INTRODUCTION: Haemostasis laboratories play a critical role in diagnosis and treatment of individuals with bleeding or thrombotic disorders. Routine coagulation assays such as prothrombin time (PT)/ international normalized ratio (INR), and activated partial thromboplastin time (APTT), are used in monitoring of anticoagulant therapy, as provided for treatment/prevention of thromboembolic disease, and also inform on potential haemostasis dysfunction. Increasing pressure is applied on clinical laboratories to improve response (test turnaround) times, reduce error rates and standardize policies. To this end, we describe our experience with the development and implementation of an automated process for reflex testing and validation of routine coagulation test results in a large pathology network compromising 27 laboratories. METHODS: Custom-built expert rules were created to perform reflex testing and fully automate routine test validation. These rules were developed/implemented over a 15-month period, including 6 months for development/ testing and 9 months for training/implementation of >100 personnel at 27 sites. RESULTS: These rules have enabled adherence of standardized pre-analytical (sample integrity) checks, automated reflex decisions, automated verification and overall alignment of network practices. In addition, clinically significant results are immediately referred to haematologists. We report an improvement in test turnaround times, also reflecting savings in operator time. CONCLUSION: The process was generally well received and generally beneficial to most laboratories in the network.


Asunto(s)
Anticoagulantes/farmacología , Automatización de Laboratorios/normas , Pruebas de Coagulación Sanguínea/normas , Coagulación Sanguínea/efectos de los fármacos , Pruebas Diagnósticas de Rutina/normas , Automatización de Laboratorios/métodos , Pruebas de Coagulación Sanguínea/métodos , Pruebas Diagnósticas de Rutina/métodos , Hemostasis/efectos de los fármacos , Humanos , Relación Normalizada Internacional , Nueva Gales del Sur , Tiempo de Tromboplastina Parcial , Tiempo de Protrombina , Estándares de Referencia , Reflejo , Reproducibilidad de los Resultados
14.
Eur J Clin Microbiol Infect Dis ; 38(10): 1961-1968, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31342215

RESUMEN

Mycobacterial culture remains the gold standard for detection of Mycobacterium tuberculosis (MTB) in clinical samples. However, no external quality assessment (EQA) tools exist to validate results obtained using this sophisticated method. Therefore, we developed EQA panels to assess the quality of mycobacterial culture results produced by designated TB hospitals in China. Artificial sputum containing methylcellulose was used to supplement quantified mycobacterial solutions to simulate culture-negative and culture-positive clinical sputum samples of low or high mycobacterial concentration, respectively. After storage of the quantified simulated EQA panels for 4 weeks at 4 °C, experimental bacterial quantification of the panels was again conducted, with no impact of artificial sputum on mycobacterial culture results observed. Next, 47 tuberculosis (TB) hospitals were recruited for evaluation of the EQA panels. Overall, 29 hospitals (61.7%) produced mycobacterial culture test results matching expected results for the EQA panels, while the remaining 18 (38.3%) hospitals did not. False-negative results for the low mycobacterial concentration panel sample accounted for 33 (73.3%) diagnostic errors. Compared with hospitals using solid culture methods as a control group, hospitals using the liquid culture method were less likely to produce uncertified results (aOR 0.064, 95% CI 0.005-0.770). In conclusion, we first developed then evaluated EQA panels for validation of mycobacterial culture testing in China. Our data demonstrate that approximately one-third of TB hospitals failed to produce results that met criteria for classification as certified mycobacterial culture testing providers, emphasizing the importance of quality control and quality assurance in TB diagnostics.


Asunto(s)
Técnicas Bacteriológicas/métodos , Pruebas Diagnósticas de Rutina/métodos , Ensayos de Aptitud de Laboratorios/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Esputo/microbiología , Tuberculosis/diagnóstico , Técnicas Bacteriológicas/normas , China , Pruebas Diagnósticas de Rutina/normas , Hospitales , Humanos
15.
BMC Med ; 17(1): 138, 2019 07 24.
Artículo en Inglés | MEDLINE | ID: mdl-31337404

RESUMEN

BACKGROUND: Delirium affects > 15% of hospitalised patients but is grossly underdetected, contributing to poor care. The 4 'A's Test (4AT, www.the4AT.com ) is a short delirium assessment tool designed for routine use without special training. The primary objective was to assess the accuracy of the 4AT for delirium detection. The secondary objective was to compare the 4AT with another commonly used delirium assessment tool, the Confusion Assessment Method (CAM). METHODS: This was a prospective diagnostic test accuracy study set in emergency departments or acute medical wards involving acute medical patients aged ≥ 70. All those without acutely life-threatening illness or coma were eligible. Patients underwent (1) reference standard delirium assessment based on DSM-IV criteria and (2) were randomised to either the index test (4AT, scores 0-12; prespecified score of > 3 considered positive) or the comparator (CAM; scored positive or negative), in a random order, using computer-generated pseudo-random numbers, stratified by study site, with block allocation. Reference standard and 4AT or CAM assessments were performed by pairs of independent raters blinded to the results of the other assessment. RESULTS: Eight hundred forty-three individuals were randomised: 21 withdrew, 3 lost contact, 32 indeterminate diagnosis, 2 missing outcome, and 785 were included in the analysis. Mean age was 81.4 (SD 6.4) years. 12.1% (95/785) had delirium by reference standard assessment, 14.3% (56/392) by 4AT, and 4.7% (18/384) by CAM. The 4AT had an area under the receiver operating characteristic curve of 0.90 (95% CI 0.84-0.96). The 4AT had a sensitivity of 76% (95% CI 61-87%) and a specificity of 94% (95% CI 92-97%). The CAM had a sensitivity of 40% (95% CI 26-57%) and a specificity of 100% (95% CI 98-100%). CONCLUSIONS: The 4AT is a short, pragmatic tool which can help improving detection rates of delirium in routine clinical care. TRIAL REGISTRATION: International standard randomised controlled trial number (ISRCTN) 53388093 . Date applied 30/05/2014; date assigned 02/06/2014.


Asunto(s)
Confusión/diagnóstico , Delirio/diagnóstico , Pruebas Diagnósticas de Rutina , Pruebas Neuropsicológicas , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Algoritmos , Lista de Verificación/métodos , Lista de Verificación/normas , Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/normas , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Servicio de Urgencia en Hospital , Femenino , Evaluación Geriátrica/métodos , Humanos , Pacientes Internos , Masculino , Pruebas Neuropsicológicas/normas , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
16.
Emerg Med J ; 36(7): 431-434, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31302605

RESUMEN

In this two-part series on sources of bias in studies of diagnostic test performance, we outline common errors and optimal conditions during three study phases: patient selection, interpretation of the index test and disease verification by a gold standard. Here in part 1, biases associated with suboptimal participant selection are discussed through the lens of partial verification bias and spectrum bias, both of which increase the proportion of participants who are the 'sickest of the sick' or the 'wellest of the well.' Especially through retrospective methodology, partial verification introduces bias by including patients who are test positive by a gold standard, since patients with a positive index test are more likely to go on to further gold standard testing. Spectrum bias is frequently introduced through case-control design, dropping of indeterminate results or convenience sampling. After reading part 1, the informed clinician should be better able to judge the quality of a diagnostic test study, its inherent limitations and whether its results could be generalisable to their practice. Part 2 will describe how interpretation of the index test and disease verification by a gold standard can contribute to diagnostic test bias.


Asunto(s)
Sesgo , Pruebas Diagnósticas de Rutina/métodos , Selección de Paciente/ética , Pruebas Diagnósticas de Rutina/normas , Pruebas Diagnósticas de Rutina/estadística & datos numéricos , Humanos , Proyectos de Investigación/normas , Proyectos de Investigación/estadística & datos numéricos , Estudios Retrospectivos
17.
Comput Math Methods Med ; 2019: 1891569, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31275427

RESUMEN

Diagnostic tests are approaches used in clinical practice to identify with high accuracy the disease of a particular patient and thus to provide early and proper treatment. Reporting high-quality results of diagnostic tests, for both basic and advanced methods, is solely the responsibility of the authors. Despite the existence of recommendation and standards regarding the content or format of statistical aspects, the quality of what and how the statistic is reported when a diagnostic test is assessed varied from excellent to very poor. This article briefly reviews the steps in the evaluation of a diagnostic test from the anatomy, to the role in clinical practice, and to the statistical methods used to show their performances. The statistical approaches are linked with the phase, clinical question, and objective and are accompanied by examples. More details are provided for phase I and II studies while the statistical treatment of phase III and IV is just briefly presented. Several free online resources useful in the calculation of some statistics are also given.


Asunto(s)
Técnicas de Laboratorio Clínico/normas , Errores Diagnósticos/prevención & control , Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/normas , Estadística como Asunto , Estudios de Cohortes , Análisis Costo-Beneficio , Estudios Transversales , Reacciones Falso Positivas , Humanos , Internet , Curva ROC , Valores de Referencia , Reproducibilidad de los Resultados , Proyectos de Investigación
18.
Scand J Trauma Resusc Emerg Med ; 27(1): 67, 2019 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-31311608

RESUMEN

BACKGROUND: Prehospital recognition of sepsis may inform case management by ambulance clinicians, as well as inform transport decisions. The objective of this study was to develop a prehospital sepsis screening tool for use by ambulance clinicians. METHODS: We derived and validated a sepsis screening tool, utilising univariable logistic regression models to identify predictors for inclusion, and multivariable logistic regression to generate the SEPSIS score. We utilised a retrospective cohort of adult patients transported by ambulance (n = 38483) to hospital between 01 July 2013 and 30 June 2014. Records were linked using LinkPlus® software. Successful linkage was achieved in 33289 cases (86%). Eligible patients included adult, non-trauma, non-mental health, non-cardiac arrest cases. Of 33289 linked cases, 22945 cases were eligible. Eligible cases were divided into derivation (n = 16063, 70%) and validation (n = 6882, 30%) cohorts. The primary outcome measure was high risk of severe illness or death from sepsis, as defined by the National Institute for Health and Care Excellence Sepsis guideline. RESULTS: 'High risk of severe illness or death from sepsis' was present in 3.7% of derivation (n = 593) and validation (n = 254) cohorts. The SEPSIS score comprises the following variables: age, respiratory rate, peripheral oxygen saturations, heart rate, systolic blood pressure, temperature and level of consciousness (p < 0.001 for all variables). Area under the curve was 0.87 (95%CI 0.85-0.88) for the derivation cohort, and 0.86 (95%CI 0.84-0.88) for the validation cohort. In an undifferentiated adult medical population, for a SEPSIS score ≥ 5, sensitivity was 0.37 (0.31-0.44), specificity was 0.96 (0.96-0.97), positive predictive value was 0.27 (0.23-0.32), negative predictive value was 0.97 (0.96-0.97), positive likelihood value was 13.5 (9.7-18.73) and the negative likelihood value was 0.83 (0.78-0.88). CONCLUSION: This is the first screening tool developed to identify NICE high risk of severe illness or death from sepsis. The SEPSIS score is significantly associated with high risk of severe illness or death from sepsis on arrival at the Emergency Department. It may assist ambulance clinicians to identify those patients with sepsis in need of antibiotic therapy. However, it requires external validation, in clinical practice by ambulance clinicians, in an independent population.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Servicios Médicos de Urgencia , Sepsis/diagnóstico , Adulto , Anciano , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
19.
Emerg Med J ; 36(8): 501-505, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31221671

RESUMEN

Multiple pitfalls can occur with the conduct and analysis of a study of diagnostic tests, resulting in biased accuracy. Our conceptual model includes three stages: patient selection, interpretation of the index test and disease verification. In part 2, we focus on (1) Interpretation bias (or workup bias): where the classification of an indeterminate index test result can bias the accuracy of a test or how lack of blinding can bias a subjective test result, and (2) Disease verification bias: where the index test result is incorporated into the gold standard or when the gold standard is applied only to a select population as the gold standard is an invasive test. In an example with age-adjusted D-dimer for pulmonary embolism, differential verification bias was a limitation due to the use of two gold standards-CT for a high-risk population and follow-up for symptoms in a low-risk population. However, there are circumstances when certain choices in study design are unavoidable, and result in biased test characteristics. In this case, the informed reader will better judge the quality of a study by recognising the potential biases and limitations by being methodical in their approach to understanding the methods, and in turn, better apply studies of diagnostic tests into their clinical practice.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Variaciones Dependientes del Observador , Proyectos de Investigación/normas , Pruebas Diagnósticas de Rutina/estadística & datos numéricos , Humanos , Proyectos de Investigación/estadística & datos numéricos , Sensibilidad y Especificidad
20.
Malar J ; 18(1): 214, 2019 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-31234871

RESUMEN

BACKGROUND: Undesirable consequences of donor Plasmodium falciparum parasitaemia on stored donor blood have been reported. Therefore, it is imperative that all prospective blood donors are screened for P. falciparum infections using sensitive techniques. In this study, the sensitivities of microscopy, rapid diagnostic test (RDT), loop-mediated isothermal amplification (LAMP) assay and selective whole genome amplification (sWGA) technique in detecting P. falciparum infections in blood donors was assessed. METHODS: Randomly selected blood donors from 5 districts in Greater Accra Region of Ghana were screened for asymptomatic P. falciparum infections. Each donor sample was screened with SD Bioline RDT kit for P. falciparum histidine rich protein 2 and Plasmodium lactate dehydrogenase antigens, sWGA and 18s-rRNA LAMP. Crude DNA LAMP (crDNA-LAMP) was compared to purified DNA LAMP (pDNA-LAMP). RESULTS: A total of 771 blood donors were screened. The respective overall prevalence of P. falciparum in Ghana by microscopy, RDT, crDNA-LAMP, pDNA-LAMP and sWGA was 7.4%, 11.8%, 16.9%, 17.5% and 18.0%. Using sWGA as the reference test, the sensitivities of microscopy, RDT, crDNA-LAMP and pDNA-LAMP were 41.0% (95% CI 32.7-49.7), 65.5% (95% CI 56.9-73.3), 82.6% (95% CI 75.8-88.3) and 95.7% (95% CI 90.1-98.4), respectively. There was near perfect agreement between LAMP and sWGA (sWGA vs. crDNA-LAMP, κ = 0.87; sWGA vs. pDNA-LAMP, κ = 0.96), while crDNA-LAMP and pDNA-LAMP agreed perfectly (κ = 0.91). Goodness of fit test indicated non-significant difference between the performance of LAMP and sWGA (crDNA-LAMP vs. sWGA: x2 = 0.71, p = 0.399 and pDNA-LAMP vs. sWGA: x2 = 0.14, p = 0.707). Finally, compared to sWGA, the performance of LAMP did not differ in detecting sub-microscopic parasitaemia (sWGA vs. crDNA-LAMP: x2 = 1.12, p = 0.290 and sWGA vs. pDNA-LAMP: x2 = 0.22, p = 0.638). CONCLUSIONS: LAMP assay agreed near perfectly with sWGA with non-significant differences in their ability to detect asymptomatic P. falciparum parasitaemia in blood donors. Therefore, it is recommended that LAMP based assays are employed to detect P. falciparum infections in blood donors due to its high sensitivity, simplicity, cost-effectiveness and user-friendliness.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Malaria Falciparum/diagnóstico , Técnicas de Amplificación de Ácido Nucleico/normas , Plasmodium falciparum/genética , Adulto , Infecciones Asintomáticas , Pruebas Diagnósticas de Rutina/métodos , Femenino , Ghana , Humanos , Masculino , Técnicas de Amplificación de Ácido Nucleico/economía , ARN Ribosómico 18S/genética , Adulto Joven
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