Predictive Accuracy of Sweep Frequency Impedance Technology in Identifying Conductive Conditions in Newborns

AbstractDiagnosing conductive conditions in newborns is challenging for both audiologists and otolaryngologists. Although high-frequency tympanometry (HFT), acoustic stapedial reflex tests, and wideband absorbance measures are useful diagnostic tools, there is performance measure variability in their detection of middle ear conditions. Additional diagnostic sensitivity and specificity measures gained through new technology such as sweep frequency impedance (SFI) measures may assist in the diagnosis of middle ear dysfunction in newborns.The purpose of this study was to determine the test performance of SFI to predict the status of the outer and middle ear in newborns against commonly used reference standards.Automated auditory brainstem response (AABR), HFT (1000 Hz), transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and SFI tests were administered to the study sample.A total of 188 neonates (98 males and 90 females) with a mean gestational age of 39.4 weeks were included in the sample. Mean age at the time of testing was 44.4 hr.Diagnostic accuracy of SFI was assessed in terms of its ability to identify conductive conditions in neonates when compared with nine different reference standards (including four single tests [AABR, HFT, TEOAE, and DPOAE] and five test batteries [HFT + DPOAE, HFT + TEOAE, DPOAE + TEOAE, DPOAE + AABR, and TEOAE + AABR]), using receiver operating characteristic (ROC) analysis and traditional test performance measures such as sensitivity and specificity.The test performance of SFI against the test battery reference standard of HFT + DPOAE and single reference standard of HFT was high with an area under the ROC curve (AROC) of 0.87 and 0.82, respectively. Although the HFT + DPOAE test battery reference standard performed better than the HFT reference standard in predicting middle ear conductive conditions in neonates, the difference in AROC was not significant. Further analysis revealed that the highest sensitivity and specificity for SFI (86% and 88%, respectively) was obtained when compared with the reference standard of HFT + DPOAE. Among the four single reference standards, SFI had the highest sensitivity and specificity (76% and 88%, respectively) when compared against the HFT reference standard.The high test performance of SFI against the HFT and HFT + DPOAE reference standards indicates that the SFI measure has appropriate diagnostic accuracy in detection of conductive conditions in newborns. Hence, the SFI test could be used as adjunct tool to identify conductive conditions in universal newborn hearing screening programs, and can also be used in diagnostic follow-up assessments.

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Diagnostic Accuracy of Stool Xpert MTB/RIF for Detection of Pulmonary Tuberculosis in Children: a Systematic Review and Meta-analysis

Journal of Clinical Microbiology ◽

10.1128/jcm.02057-18 ◽

2019 ◽

Vol 57 (6) ◽

Cited By ~ 18

Author(s):

Emily MacLean ◽

Giorgia Sulis ◽

Claudia M. Denkinger ◽

James C. Johnston ◽

Madhukar Pai ◽

...

Keyword(s):

Systematic Review ◽

Pulmonary Tuberculosis ◽

Diagnostic Accuracy ◽

Sensitivity And Specificity ◽

Meta Analysis ◽

Target Population ◽

Nucleic Acid Amplification ◽

Reference Standard ◽

Noninvasive Method ◽

High Data

ABSTRACT Invasive collection methods are often required to obtain samples for the microbiological evaluation of children with presumptive pulmonary tuberculosis (PTB). Nucleic acid amplification testing of easier-to-collect stool samples could be a noninvasive method of diagnosing PTB. We conducted a systematic review and meta-analysis to evaluate the diagnostic accuracy of testing stool with the Xpert MTB/RIF assay (“stool Xpert”) for childhood PTB. Four databases were searched for publications from January 2008 to June 2018. Studies assessing the diagnostic accuracy among children of stool Xpert compared to a microbiological reference standard of conventional specimens tested by mycobacterial culture or Xpert were eligible. Bivariate random-effects meta-analyses were performed to calculate pooled sensitivity and specificity of stool Xpert against the reference standard. From 1,589 citations, 9 studies (n = 1,681) were included. Median participant ages ranged from 1.3 to 10.6 years. Protocols for stool processing and testing varied substantially, with differences in reagents and methods of homogenization and filtering. Against the microbiological reference standard, the pooled sensitivity and specificity of stool Xpert were 67% (95% confidence interval [CI], 52 to 79%) and 99% (95% CI, 98 to 99%), respectively. Sensitivity was higher among children with HIV (79% [95% CI, 68 to 87%] versus 60% [95% CI, 44 to 74%] among HIV-uninfected children). Heterogeneity was high. Data were insufficient for subgroup analyses among children under the age of 5 years, the most relevant target population. Stool Xpert could be a noninvasive method of ruling in PTB in children, particularly those with HIV. However, studies focused on children under 5 years of age are needed, and generalizability of the evidence is limited by the lack of standardized stool preparation and testing protocols.

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Normative Sweep Frequency Impedance Measures in Healthy Neonates

Journal of the American Academy of Audiology ◽

10.3766/jaaa.25.4.6 ◽

2014 ◽

Vol 25 (04) ◽

pp. 343-354 ◽

Cited By ~ 7

Author(s):

Venkatesh Aithal ◽

Joseph Kei ◽

Carlie Driscoll ◽

Andrew Swanston ◽

Katrina Roberts ◽

...

Keyword(s):

Middle Ear ◽

Otoacoustic Emissions ◽

Static Pressure ◽

Auditory Brainstem ◽

Ear Canal ◽

Sweep Frequency ◽

Tone Frequency ◽

Automated Auditory Brainstem Response ◽

Brainstem Response ◽

Stapedial Reflex

Background: Diagnosing middle ear disorders in neonates is a challenging task for both audiologists and otolaryngologists. Although high-frequency (1000 Hz) tympanometry and acoustic stapedial reflex tests are useful in diagnosing middle ear problems in this age group, they do not provide information about the dynamics of the middle ear in terms of its resonance frequency (RF) and mobility. The sweep frequency impedance (SFI) test can provide this information, which may assist in the diagnosis of middle ear dysfunction in neonates. Purpose: This study aimed to investigate the feasibility of testing neonates using the SFI technique, establish normative SFI data for RF and mobility of the middle ear in terms of changes in sound pressure level (ΔSPL in dB), and describe the dynamics of the middle ear in healthy Australian neonates. Study Sample: A prospective sample of 100 neonates (58 males, 42 females) with a mean gestational age of 39.3 wk (SD = 1.3 wk; range = 38–42 wk), who passed all three tests, namely, automated auditory brainstem response, transient evoked otoacoustic emissions, and 1000 Hz tympanometry, were included in this study. Data Collection and Analysis: A SFI research prototype was used to collect the data. First, the SPL in the ear canal was measured as a probe-tone frequency was swept from 100–2000 Hz with the ear canal static pressure held constant at 200 daPa. Then, this measurement was repeated with the static pressure reduced in 50 daPa steps to –200 daPa. Additional measurement was also performed at the static pressure, where the peak of the 1000 Hz tympanogram occurred. A graph showing the variation of SPL against frequency at all static pressures was plotted. From this graph, the RF and ΔSPL at tympanometric peak pressure (TPP) were determined. Descriptive statistics and an analysis of variance (ANOVA) were applied to the RF and ΔSPL data with gender and ear as independent variables. Results: The results showed two resonance regions of the outer/middle ear with the high RF (mean = 1236 Hz; 90% range: 830–1518 Hz) being approximately equal to four times that of the low RF (mean = 287 Hz; 90% range = 209–420 Hz). The low RF was more easily identifiable than the high RF. The ΔSPL at the low RF (mean = 8.2 dB; 90% range = 3.4–13 dB) was greater than that at the high RF (mean = 5.0 dB; 90% range = 1.5–8.1 dB). There were no significant differences or interactions between genders and ears. Conclusion: The study showed that the SFI is a feasible test of middle ear function in neonates. The SFI results revealed two regions of resonance with the lower resonance (287 Hz) possibly related to the movements of the outer ear canal wall and higher resonance (1236 Hz) related to the resonance of the middle ear. The normative data developed in this study will be useful in evaluating outer and middle ear function in neonates.

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Diagnostic Accuracy of Rapid Antigen Detection Tests for Respiratory Syncytial Virus Infection: Systematic Review and Meta-analysis

Journal of Clinical Microbiology ◽

10.1128/jcm.01816-15 ◽

2015 ◽

Vol 53 (12) ◽

pp. 3738-3749 ◽

Cited By ~ 87

Author(s):

Caroline Chartrand ◽

Nicolas Tremblay ◽

Christian Renaud ◽

Jesse Papenburg

Keyword(s):

Systematic Review ◽

Respiratory Syncytial Virus ◽

Diagnostic Accuracy ◽

Sensitivity And Specificity ◽

Meta Analysis ◽

Reference Standard ◽

Rt Pcr ◽

Test Sensitivity ◽

Subgroup Analyses ◽

Syncytial Virus

Respiratory syncytial virus (RSV) rapid antigen detection tests (RADT) are extensively used in clinical laboratories. We performed a systematic review and meta-analysis to evaluate the accuracy of RADTs for diagnosis of RSV infection and to determine factors associated with accuracy estimates. We searched EMBASE and PubMed for diagnostic-accuracy studies of commercialized RSV RADTs. Studies reporting sensitivity and specificity data compared to a reference standard (reverse transcriptase PCR [RT-PCR], immunofluorescence, or viral culture) were considered. Two reviewers independently extracted data on study characteristics, diagnostic-accuracy estimates, and study quality. Accuracy estimates were pooled using bivariate random-effects regression models. Heterogeneity was investigated with prespecified subgroup analyses. Seventy-one articles met inclusion criteria. Overall, RSV RADT pooled sensitivity and specificity were 80% (95% confidence interval [CI], 76% to 83%) and 97% (95% CI, 96% to 98%), respectively. Positive- and negative-likelihood ratios were 25.5 (95% CI, 18.3 to 35.5) and 0.21 (95% CI, 0.18 to 0.24), respectively. Sensitivity was higher in children (81% [95% CI, 78%, 84%]) than in adults (29% [95% CI, 11% to 48%]). Because of this disparity, further subgroup analyses were restricted to pediatric data (63 studies). Test sensitivity was poorest using RT-PCR as a reference standard and highest using immunofluorescence (74% versus 88%;P< 0.001). Industry-sponsored studies reported significantly higher sensitivity (87% versus 78%;P= 0.01). Our results suggest that the poor sensitivity of RSV RADTs in adults may preclude their use in this population. Furthermore, industry-sponsored studies and those that did not use RT-PCR as a reference standard likely overestimated test sensitivity.

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Use of Smartphones to Detect Diabetic Retinopathy: Scoping Review and Meta-Analysis of Diagnostic Test Accuracy Studies (Preprint)

10.2196/preprints.16658 ◽

2019 ◽

Author(s):

Choon Han Tan ◽

Bhone Myint Kyaw ◽

Helen Smith ◽

Colin S Tan ◽

Lorainne Tudor Car

Keyword(s):

Diabetic Retinopathy ◽

Diagnostic Accuracy ◽

Diagnostic Test ◽

Sensitivity And Specificity ◽

Meta Analysis ◽

Diagnostic Test Accuracy ◽

Fundus Photography ◽

Diabetic Patients ◽

Test Accuracy ◽

Reference Standard

BACKGROUND Diabetic retinopathy (DR), a common complication of diabetes mellitus, is the leading cause of impaired vision in adults worldwide. Smartphone ophthalmoscopy involves using a smartphone camera for digital retinal imaging. Utilizing smartphones to detect DR is potentially more affordable, accessible, and easier to use than conventional methods. OBJECTIVE This study aimed to determine the diagnostic accuracy of various smartphone ophthalmoscopy approaches for detecting DR in diabetic patients. METHODS We performed an electronic search on the Medical Literature Analysis and Retrieval System Online (MEDLINE), EMBASE, and Cochrane Library for literature published from January 2000 to November 2018. We included studies involving diabetic patients, which compared the diagnostic accuracy of smartphone ophthalmoscopy for detecting DR to an accurate or commonly employed reference standard, such as indirect ophthalmoscopy, slit-lamp biomicroscopy, and tabletop fundus photography. Two reviewers independently screened studies against the inclusion criteria, extracted data, and assessed the quality of included studies using the Quality Assessment of Diagnostic Accuracy Studies–2 tool, with disagreements resolved via consensus. Sensitivity and specificity were pooled using the random effects model. A summary receiver operating characteristic (SROC) curve was constructed. This review is reported in line with the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies guidelines. RESULTS In all, nine studies involving 1430 participants were included. Most studies were of high quality, except one study with limited applicability because of its reference standard. The pooled sensitivity and specificity for detecting any DR was 87% (95% CI 74%-94%) and 94% (95% CI 81%-98%); mild nonproliferative DR (NPDR) was 39% (95% CI 10%-79%) and 95% (95% CI 91%-98%); moderate NPDR was 71% (95% CI 57%-81%) and 95% (95% CI 88%-98%); severe NPDR was 80% (95% CI 49%-94%) and 97% (95% CI 88%-99%); proliferative DR (PDR) was 92% (95% CI 79%-97%) and 99% (95% CI 96%-99%); diabetic macular edema was 79% (95% CI 63%-89%) and 93% (95% CI 82%-97%); and referral-warranted DR was 91% (95% CI 86%-94%) and 89% (95% CI 56%-98%). The area under SROC curve ranged from 0.879 to 0.979. The diagnostic odds ratio ranged from 11.3 to 1225. CONCLUSIONS We found heterogeneous evidence showing that smartphone ophthalmoscopy performs well in detecting DR. The diagnostic accuracy for PDR was highest. Future studies should standardize reference criteria and classification criteria and evaluate other available forms of smartphone ophthalmoscopy in primary care settings.

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Tuberculosis diagnostic accuracy of stool Xpert MTB/RIF and urine AlereLAM in vulnerable children

European Respiratory Journal ◽

10.1183/13993003.01116-2021 ◽

2021 ◽

pp. 2101116

Author(s):

Patrick Orikiriza ◽

Julianna Smith ◽

Bob Ssekyanzi ◽

Dan Nyehangane ◽

Ivan Mugisha Taremwa ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Sensitivity And Specificity ◽

Severe Malnutrition ◽

Hiv Positive ◽

Age Group ◽

Reference Standard ◽

Hiv Status ◽

Vulnerable Children ◽

Diagnostic Approaches ◽

Composite Reference Standard

BackgroundNon-sputum based diagnostic approaches are crucial in children at high risk of disseminated tuberculosis [TB] who cannot expectorate sputum. We evaluated the diagnostic accuracy of Xpert MTB/RIF from stool and urine AlereLipoarabinomannan [LAM] test in this group of children.MethodsHospitalised children with presumptive TB and either age <2 years, HIV-positive or severe malnutrition were enrolled in a diagnostic cohort. At enrolment, we attempted to collect two urine, two stool and two respiratory samples. Urine and stool were tested with AlereLAM and Xpert MTB/RIF, respectively. Respiratory samples were tested with Xpert MTB/RIF and mycobacterial culture. Both a microbiological and a composite clinical reference standard were used.ResultsThe study enrolled 219 children; median age 16.4 months, 72 (32.9%) HIV-positive and 184 (84.4%) severely malnourished. Twelve (5.5%) and 58 (28.5%) children had confirmed and unconfirmed TB respectively. Stool and urine were collected in 219 (100%) and 216 (98.6%) children. Against the microbiological reference standard the sensitivity and specificity (n/N, 95% confidence intervals) of stool Xpert MTB/RIF was 50.0% (6/12, 21.1–78.9) and 99.1% (198/200 96.4–99.9), while that of urine AlereLAM was 50.0% (6/12, 21.1–78.9) and 74.6% (147/197, 67.9–80.5) respectively. Against the composite reference standard sensitivity was reduced to 11.4% (8/70) for stool and 26.2% (17/68) for urine, with no major difference by age group (<2 and >2 years) or HIV status.ConclusionThe Xpert MTB/RIF assay has excellent specificity on stool, but sensitivity is suboptimal. Urine AlereLAM is compromised by poor sensitivity and specificity in children.

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Diagnostic Accuracy of Ultrasound and MRI in the Mapping of Deep Pelvic Endometriosis Using the International Deep Endometriosis Analysis (IDEA) Consensus

BioMed Research International ◽

10.1155/2020/3583989 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

T. Indrielle-Kelly ◽

F. Frühauf ◽

M. Fanta ◽

A. Burgetova ◽

D. Lavu ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Sensitivity And Specificity ◽

Lower Sensitivity ◽

Pelvic Endometriosis ◽

Reference Standard ◽

Deep Endometriosis ◽

Preoperative Mapping ◽

Index Tests ◽

Deep Pelvic Endometriosis ◽

Good Agreement

Objectives. The primary aim was to investigate the diagnostic accuracy of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) in the mapping of deep pelvic endometriosis (DE) in a diseased population. The secondary aim was to offer first insights into the clinical applicability of the new International Deep Endometriosis Analysis group (IDEA) consensus for sonographic evaluation, which was also adapted for MRI and surgical reporting in this study. Methods. The study was a prospective observational cohort study. In this study, consecutive women planned for surgical treatment for DE underwent preoperative mapping of pelvic disease using TVS and MRI (index tests). The results were compared against the intraoperative findings with histopathological confirmation (reference standard). In case of disagreement between intraoperative and pathology findings, the latter was prioritised. Index tests and surgical findings were reported using a standardised protocol based on the IDEA consensus. Results. The study ran from 07/2016 to 02/2018. One-hundred and eleven women were approached, but 60 declined participation. Out of the 51 initially recruited women, two were excluded due to the missing reference standard. Both methods (TVS and MRI) had the same sensitivity and specificity in the detection of DE in the upper rectum (UpR) and rectosigmoid (RS) (UpR TVS and MRI sensitivity and specificity 100%; RS TVS and MRI sensitivity 94%; TVS and MRI specificity 84%). In the assessment of DE in the bladder (Bl), uterosacral ligaments (USL), vagina (V), rectovaginal septum (RVS), and overall pelvis (P), TVS had marginally higher specificity but lower sensitivity than MRI (Bl TVS sensitivity 89%, specificity 100%, MRI sensitivity 100%, specificity 95%; USL TVS sensitivity 74%, specificity 67%, MRI sensitivity 94%, specificity 60%; V TVS sensitivity 55%, specificity 100%, MRI sensitivity 73%, specificity 95%; RVS TVS sensitivity 67%, specificity 100%, MRI sensitivity 83%, specificity 93%; P TVS sensitivity 78%, specificity 97%, MRI sensitivity 91%, specificity 91%). No significant differences in diagnostic accuracy between TVS and MRI were observed except USL assessment (p=0.04) where MRI was significantly better and pouch of Douglas obliteration (p=0.04) where TVS was significantly better. Overall, there was a good agreement between reference standards and both index tests (TVS kappa value (κ) = 0.727 [p≤0.001), MRI κ = 0.755 [p=p≤0.001]). Conclusion. We found that both imaging techniques had overall good agreement with the reference standard in the detection of deep pelvic endometriosis. This is the first study to date involving the IDEA consensus for ultrasound, its modified version for MRI, and intraoperative reporting of deep pelvic endometriosis in clinical practice.

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Comparative diagnostic accuracy studies with an imperfect reference standard – a comparison of correction methods

BMC Medical Research Methodology ◽

10.1186/s12874-021-01255-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Chinyereugo M. Umemneku Chikere ◽

Kevin J. Wilson ◽

A. Joy Allen ◽

Luke Vale

Keyword(s):

Diagnostic Accuracy ◽

Sensitivity And Specificity ◽

Latent Class ◽

Clinical Decision Making ◽

Disease Status ◽

Clinical Decision ◽

Correction Method ◽

Index Test ◽

Reference Standard ◽

The Impact

Abstract Background Staquet et al. and Brenner both developed correction methods to estimate the sensitivity and specificity of a binary-response index test when the reference standard is imperfect and its sensitivity and specificity are known. However, to our knowledge, no study has compared the statistical properties of these methods, despite their long application in diagnostic accuracy studies. Aim To compare the correction methods developed by Staquet et al. and Brenner. Methods Simulations techniques were employed to compare the methods under assumptions that the new test and the reference standard are conditionally independent or dependent given the true disease status of an individual. Three clinical datasets were analysed to understand the impact of using each method to inform clinical decision-making. Results Under the assumption of conditional independence, the Staquet et al. correction method outperforms the Brenner correction method irrespective of the prevalence of disease and whether the performance of the reference standard is better or worse than the index test. However, when the prevalence of the disease is high (> 0.9) or low (< 0.1), the Staquet et al. correction method can produce illogical results (i.e. results outside [0,1]). Under the assumption of conditional dependence; both methods failed to estimate the sensitivity and specificity of the index test especially when the covariance terms between the index test and the reference standard is not close to zero. Conclusion When the new test and the imperfect reference standard are conditionally independent, and the sensitivity and specificity of the imperfect reference standard are known, the Staquet et al. correction method outperforms the Brenner method. However, where the prevalence of the target condition is very high or low or the two tests are conditionally dependent, other statistical methods such as latent class approaches should be considered.

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Accuracy of the Patient Health Questionnaire-9 for screening to detect major depression: updated systematic review and individual participant data meta-analysis

BMJ ◽

10.1136/bmj.n2183 ◽

2021 ◽

pp. n2183

Author(s):

Zelalem F Negeri ◽

Brooke Levis ◽

Ying Sun ◽

Chen He ◽

Ankur Krishnan ◽

...

Keyword(s):

Major Depression ◽

Sensitivity And Specificity ◽

Meta Analysis ◽

Diagnostic Interview ◽

Reference Standards ◽

Individual Participant Data ◽

Health Questionnaire ◽

Reference Standard ◽

Patient Health ◽

Individual Participant

Abstract Objective To update a previous individual participant data meta-analysis and determine the accuracy of the Patient Health Questionnaire-9 (PHQ-9), the most commonly used depression screening tool in general practice, for detecting major depression overall and by study or participant subgroups. Design Systematic review and individual participant data meta-analysis. Data sources Medline, Medline In-Process, and Other Non-Indexed Citations via Ovid, PsycINFO, Web of Science searched through 9 May 2018. Review methods Eligible studies administered the PHQ-9 and classified current major depression status using a validated semistructured diagnostic interview (designed for clinician administration), fully structured interview (designed for lay administration), or the Mini International Neuropsychiatric Interview (MINI; a brief interview designed for lay administration). A bivariate random effects meta-analytic model was used to obtain point and interval estimates of pooled PHQ-9 sensitivity and specificity at cut-off values 5-15, separately, among studies that used semistructured diagnostic interviews (eg, Structured Clinical Interview for Diagnostic and Statistical Manual), fully structured interviews (eg, Composite International Diagnostic Interview), and the MINI. Meta-regression was used to investigate whether PHQ-9 accuracy correlated with reference standard categories and participant characteristics. Results Data from 44 503 total participants (27 146 additional from the update) were obtained from 100 of 127 eligible studies (42 additional studies; 79% eligible studies; 86% eligible participants). Among studies with a semistructured interview reference standard, pooled PHQ-9 sensitivity and specificity (95% confidence interval) at the standard cut-off value of ≥10, which maximised combined sensitivity and specificity, were 0.85 (0.79 to 0.89) and 0.85 (0.82 to 0.87), respectively. Specificity was similar across reference standards, but sensitivity in studies with semistructured interviews was 7-24% (median 21%) higher than with fully structured reference standards and 2-14% (median 11%) higher than with the MINI across cut-off values. Across reference standards and cut-off values, specificity was 0-10% (median 3%) higher for men and 0-12 (median 5%) higher for people aged 60 or older. Conclusions Researchers and clinicians could use results to determine outcomes, such as total number of positive screens and false positive screens, at different PHQ-9 cut-off values for different clinical settings using the knowledge translation tool at www.depressionscreening100.com/phq . Study registration PROSPERO CRD42014010673.

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SARS-CoV-2 lateral flow assays for possible use in national covid-19 seroprevalence surveys (React 2): diagnostic accuracy study

BMJ ◽

10.1136/bmj.n423 ◽

2021 ◽

pp. n423 ◽

Cited By ~ 1

Author(s):

Maya Moshe ◽

Anna Daunt ◽

Barnaby Flower ◽

Bryony Simmons ◽

Jonathan C Brown ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Sensitivity And Specificity ◽

Lateral Flow ◽

Reference Standards ◽

Superior Performance ◽

Sensitivity Analyses ◽

Diagnostic Accuracy Study ◽

Serum Samples ◽

Finger Prick ◽

Accuracy Study

Abstract Objective To evaluate the performance of new lateral flow immunoassays (LFIAs) suitable for use in a national coronavirus disease 2019 (covid-19) seroprevalence programme (real time assessment of community transmission 2—React 2). Design Diagnostic accuracy study. Setting Laboratory analyses were performed in the United Kingdom at Imperial College, London and university facilities in London. Research clinics for finger prick sampling were run in two affiliated NHS trusts. Participants Sensitivity analyses were performed on sera stored from 320 previous participants in the React 2 programme with confirmed previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Specificity analyses were performed on 1000 prepandemic serum samples. 100 new participants with confirmed previous SARS-CoV-2 infection attended study clinics for finger prick testing. Interventions Laboratory sensitivity and specificity analyses were performed for seven LFIAs on a minimum of 200 serum samples from participants with confirmed SARS-CoV-2 infection and 500 prepandemic serum samples, respectively. Three LFIAs were found to have a laboratory sensitivity superior to the finger prick sensitivity of the LFIA currently used in React 2 seroprevalence studies (84%). These LFIAs were then further evaluated through finger prick testing on participants with confirmed previous SARS-CoV-2 infection: two LFIAs (Surescreen, Panbio) were evaluated in clinics in June-July 2020 and the third LFIA (AbC-19) in September 2020. A spike protein enzyme linked immunoassay and hybrid double antigen binding assay were used as laboratory reference standards. Main outcome measures The accuracy of LFIAs in detecting immunoglobulin G (IgG) antibodies to SARS-CoV-2 compared with two reference standards. Results The sensitivity and specificity of seven new LFIAs that were analysed using sera varied from 69% to 100%, and from 98.6% to 100%, respectively (compared with the two reference standards). Sensitivity on finger prick testing was 77% (95% confidence interval 61.4% to 88.2%) for Panbio, 86% (72.7% to 94.8%) for Surescreen, and 69% (53.8% to 81.3%) for AbC-19 compared with the reference standards. Sensitivity for sera from matched clinical samples performed on AbC-19 was significantly higher with serum than finger prick at 92% (80.0% to 97.7%, P=0.01). Antibody titres varied considerably among cohorts. The numbers of positive samples identified by finger prick in the lowest antibody titre quarter varied among LFIAs. Conclusions One new LFIA was identified with clinical performance suitable for potential inclusion in seroprevalence studies. However, none of the LFIAs tested had clearly superior performance to the LFIA currently used in React 2 seroprevalence surveys, and none showed sufficient sensitivity and specificity to be considered for routine clinical use.

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Nerve ultrasound for diagnosing chronic inflammatory neuropathy

Neurology ◽

10.1212/wnl.0000000000010369 ◽

2020 ◽

Vol 95 (12) ◽

pp. e1745-e1753

Author(s):

Ingrid J.T. Herraets ◽

H. Stephan Goedee ◽

Johan A. Telleman ◽

Ruben P.A. van Eijk ◽

Camiel Verhamme ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Sensitivity And Specificity ◽

Multicenter Study ◽

Added Value ◽

Response Alternative ◽

European Federation ◽

Motor Neuropathy ◽

Reference Standard ◽

Nerve Ultrasound ◽

Inflammatory Neuropathy

ObjectiveTo validate the diagnostic accuracy of a previously described short sonographic protocol to identify chronic inflammatory neuropathy (CIN), including chronic inflammatory demyelinating polyneuropathy (CIDP), Lewis Sumner syndrome, and multifocal motor neuropathy (MMN), and to determine the added value of nerve ultrasound to detect treatment-responsive patients compared to nerve conduction studies (NCS) in a prospective multicenter study.MethodsWe included 100 consecutive patients clinically suspected of CIN in 3 centers. The study protocol consisted of neurologic examination, laboratory tests, NCS, and nerve ultrasound. We validated a short sonographic protocol (median nerve at forearm, upper arm, and C5 nerve root) and determined its diagnostic accuracy using the European Federation of Neurological Societies/Peripheral Nerve Society criteria of CIDP/MMN (reference standard). In addition, to determine the added value of nerve ultrasound in detecting treatment-responsive patients, we used previously published diagnostic criteria based on clinical, NCS, and sonographic findings and treatment response (alternative reference standard).ResultsSensitivity and specificity of the sonographic protocol for CIN according to the reference standard were 87.4% and 67.3%, respectively. Sensitivity and specificity of this protocol according to the alternative reference standard were 84.6% and 72.8%, respectively, and of NCS 76.1% and 93.4%. With addition of nerve ultrasound, 44 diagnoses of CIN were established compared to 33 diagnoses with NCS alone.ConclusionsA short sonographic protocol shows high diagnostic accuracy for detecting CIN. Nerve ultrasound is able to detect up to 25% more patients who respond to treatment.Classification of evidenceThis multicenter study provides Class IV evidence that nerve ultrasound improves diagnosis of CIN.

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