Diagnostic accuracy of SARS-CoV-2 saliva antigen testing in a real-life clinical setting.

BACKGROUND SARS-CoV-2 antigen tests with saliva facilitate examination in settings that lack trained personnel. However, little is known on the diagnostic accuracy in real-life clinical settings. Therefore, we studied the diagnostic accuracy of a saliva antigen test to diagnose SARS-CoV-2 infection in a primary/ secondary care testing facility. METHODS Individuals presented at a COVID-19 testing facility affiliated with a Swiss University Hospital were prospectively recruited (n=377). Saliva specimen was obtained, and the PCL Inc. COVID19 Gold antigen test was conducted in parallel with two real-time PCR. RESULTS RT-PCR was positive in 53 individuals, corresponding to a prevalence of 14.1% (missing material in one individual). The PCL saliva antigen test was positive in 22 individuals (5.8%), and negative in 354 (93.9%). The sensitivity of the saliva antigen test was 30.2% (95% confidence interval, CI, 18.3 to 44.3), both overall and in symptomatic individiduals. The specificity was 98.1% (96.0, 99.3). CONCLUSIONS The diagnostic accuracy of a SARS-CoV-2 saliva antigen test in a primary/ secondary care testing facility was remarkably lower compared to the manufacturers' specifications. Keywords Infections/*epidemiology/transmission; severe acute respiratory syndrome coronavirus 2 [Supplementary Concept]; COVID-19 diagnostic testing [Supplementary Concept] Background

Determination of the Diagnostic Performance of Laboratory Tests in the Absence of a Perfect Reference Standard: The Case of SARS-CoV-2 Tests

Background: Currently, assessing the diagnostic performance of new laboratory tests assumes a perfect reference standard, which is rarely the case. Wrong classifications of the true disease status will inevitably lead to biased estimates of sensitivity and specificity. Objectives: Using Bayesian’ latent class models (BLCMs), an approach that does not assume a perfect reference standard, we re-analyzed data of a large prospective observational study assessing the diagnostic accuracy of an antigen test for the diagnosis of SARS-CoV-2 infection in clinical practice. Methods: A cohort of consecutive patients presenting to a COVID-19 testing facility affiliated with a Swiss University Hospital were recruited (n = 1465). Two real-time PCR tests were conducted in parallel with the Roche/SD Biosensor rapid antigen test on nasopharyngeal swabs. A two-test (PCR and antigen test), three-population BLCM was fitted to the frequencies of paired test results. Results: Based on the BLCM, the sensitivities of the RT-PCR and the Roche/SD Biosensor rapid antigen test were 98.5% [95% CRI 94.8;100] and 82.7% [95% CRI 66.8;100]. The specificities were 97.7% [96.1;99.7] and 99.9% [95% CRI 99.6;100]. Conclusions: Applying the BLCM, the diagnostic accuracy of RT-PCR was high but not perfect. In contrast to previous results, the sensitivity of the antigen test was higher. Our results suggest that BLCMs are valuable tools for investigating the diagnostic performance of laboratory tests in the absence of perfect reference standard

Favourable neurological outcome following paediatric out-of-hospital cardiac arrest: a retrospective observational study

BACKGROUND Out-of-hospital cardiac arrest (OHCA) in children is rare and can potentially result in severe neurological impairment. Our study aimed to identify characteristics of and factors associated with favourable neurological outcome following the resuscitation of children by the Swiss helicopter emergency medical service. MATERIALS AND METHODS This retrospective observational study screened the Swiss Air-Ambulance electronic database from 01-01-2011 to 31-12-2021. We included all primary missions for patients ≤ 16 years with OHCA. The primary outcome was favourable neurological outcome after 30 days (cerebral performance categories (CPC) 1 and 2). Multivariable linear regression identified potential factors associated with favourable outcome (odd ratio - OR). RESULTS Having screened 110,331 missions, we identified 296 children with OHCA, which we included in the analysis. Patients were 5.0 [1.0; 12.0] years old and 61.5% (n = 182) male. More than two-thirds had a non-traumatic OHCA (67.2%, n = 199), while 32.8% (n = 97) had a traumatic OHCA. Thirty days after the event, 24.0% (n = 71) of patients were alive, 18.9% (n = 56) with a favourable neurological outcome (CPC 1 n = 46, CPC 2 n = 10). Bystander cardiopulmonary resuscitation (OR 10.34; 95%CI 2.29-51.42; p = 0.002) and non-traumatic aetiology (OR 11.07 2.38-51.42; p = 0.002) were the factors most strongly associated with favourable outcome. Factors associated with an unfavourable neurological outcome were initial asystole (OR 0.12; 95%CI 0.04-0.39; p < 0.001), administration of adrenaline (OR 0.14; 95%CI 0.05-0.39; p < 0.001) and ongoing chest compression at HEMS arrival (OR 0.17; 95%CI 0.04-0.65; p = 0.010). CONCLUSION In this study, 18.9% of paediatric OHCA patients survived with a favourable neurologic outcome 30 days after treatment by the Swiss helicopter emergency medical service. Immediate bystander cardiopulmonary resuscitation and non-traumatic OHCA aetiology were the factors most strongly associated with a favourable neurological outcome. These results underline the importance of effective bystander and first-responder rescue as the foundation for subsequent professional treatment of children in cardiac arrest

Recent incidence and surgery trends for prostate cancer: Towards an attenuation of overdiagnosis and overtreatment?

Screening for prostate cancer is frequent in high-income countries, including Switzerland. Notably due to overdiagnosis and overtreatment, various organisations have recently recommended against routine screening, potentially having an impact on incidence, mortality, and surgery rates. Our aim was therefore to examine whether secular trends in the incidence and mortality of prostate cancer, and in prostatectomy rates, have recently changed in Switzerland. We conducted a population-based trend study in Switzerland from 1998 to 2012. Cases of invasive prostate cancer, deaths from prostate cancer, and prostatectomies were analysed. We calculated changes in age-standardised prostate cancer incidence rates, stratified by tumor stage (early, advanced), prostate cancer-specific mortality, and prostatectomy rates. The age-standardised incidence rate of prostate cancer increased greatly in men aged 50-69 years (absolute mean annual change +4.6/100,000, 95% CI: +2.9 to +6.2) between 1998 and 2002, and stabilised afterwards. In men aged ≥ 70 years, the incidence decreased slightly between 1998 and 2002, and more substantially since 2003. The incidence of early tumor stages increased between 1998 and 2002 only in men aged 50-69 years, and then stabilised, while the incidence of advanced stages remained stable across both age strata. The rate of prostatectomy increased markedly until 2002, more so in the 50 to 69 age range than among men aged ≥ 70 years; it leveled off after 2002 in both age strata. Trends in surgery were driven by radical prostatectomy. Since 1998, the annual age-standardised mortality rate of prostate cancer slightly declined in men aged 50-69 years (absolute mean annual change -0.1/100,000, 95% CI: -0.2 to -0.1) and ≥ 70 years (absolute mean annual change -0.5/100,000, 95% CI: -0.7 to -0.3). The increases in the incidence of early stage prostate cancer and prostatectomy observed in Switzerland among men younger than 70 years have concomitantly leveled off around 2002/2003. Given the decreasing mortality, these trends may reflect recent changes in screening and clinical workup practices, with a possible attenuation of overdiagnosis and overtreatment

Overdiagnosis and overtreatment of thyroid cancer: A population-based temporal trend study.

BACKGROUND The increase in incidence of thyroid cancer during the last decades without concomitant rise in mortality may reflect the growing detection of indolent forms of thyroid cancer, and may have fueled unnecessary thyroidectomies. Our aim was therefore, to compare recent secular trends in surgical intervention rate for thyroid cancer with the incidence and mortality of thyroid cancer to assess overdiagnosis and resulting overtreatment. METHODS We conducted a population-based temporal trend study in Switzerland from 1998 to 2012. All cases of invasive thyroid cancer, deaths from thyroid cancer, and cancer-related thyroidectomies were analyzed. We calculated changes in age-standardized thyroid cancer incidence rates, stratified by histologic subtype and tumor stage, thyroid cancer-specific mortality, and thyroidectomy rates. RESULTS Between 1998 and 2012, the age-standardized annual incidence of thyroid cancer increased from 5.9 to 11.7 cases/100,000 among women (annual mean absolute increase: +0.43/100,000/year) and from 2.7 to 3.9 cases/100,000 among men (+0.11/100,000/year). The increase was limited to the papillary subtype, the most indolent form of thyroid cancer. The incidence of early stages increased sharply, the incidence of advanced stages increased marginally, and the mortality from thyroid cancer decreased slightly. There was a three- to four-fold increase in the age-standardized annual thyroidectomy rate in both sexes. CONCLUSIONS We observed a large increase in the incidence of thyroid cancer, limited to papillary and early stage tumors, with a three- to four-fold parallel increase in thyroidectomy. The mortality slightly decreased. These findings suggest that a substantial and growing part of the detected thyroid cancers are overdiagnosed and overtreated. IMPACT Targeted screening and diagnostic strategies are warranted to avoid overdetection and unnecessary treatment of thyroid cancers

Diagnostic accuracy of a SARS-CoV-2 rapid antigen test in real-life clinical settings.

BACKGROUND Laboratory tests are a mainstay in managing the COVID-19 pandemic, and high hopes are placed on rapid antigen tests. However, the accuracy of rapid antigen tests in real-life clinical settings is unclear because adequately designed diagnostic accuracy studies are essentially lacking. OBJECTIVES We aimed to assess the diagnostic accuracy of a rapid antigen test to diagnose SARS-CoV-2 infection in a primary/ secondary care testing facility. METHODS Consecutive individuals presented at a COVID-19 testing facility affiliated to a Swiss University Hospital were recruited (n=1'465%). Nasopharyngeal swabs were obtained, and the Roche/ SD Biosensor rapid antigen test was conducted in-parallel with two real-time PCR (reference standard). RESULTS Among 1'465 patients recruited, RT-PCR was positive in 141 individuals, corresponding to a prevalence of prevalence 9.6%. The Roche/ SD Biosensor rapid antigen test was positive in 94 patients (6.4%), and negative in 1'368 individuals (93.4%). The overall sensitivity of the rapid antigen test was 65.3% (95% confidence interval, CI, 56.8, 73.1), the specificity was 99.9% (95%CI 99.5, 100.0). In asymptomatic individuals, the sensitivity was 44.0% (95%CI 24.4, 65.1). CONCLUSIONS The diagnostic accuracy of the SARS-CoV-2 Roche/SD Biosensor rapid antigen test to diagnose a SARS-CoV-2 infection in a primary/ secondary care testing facility was considerably lower compared to manufacturers' data. Widespread application in this setting might lead to a considerable number of individuals falsely classified as SARS-CoV-2 negative

Mythen und Missverständnisse in der Notfall-Labormedizin – Treat the Patient, Not the Blood Test

Verbessertes Verständnis der menschlichen Physiologie und technische Fortschritte haben zu einer breiten Verwendung von Labordiagnostik in der klinischen Aufarbeitung eines Patienten geführt. Diese Entwicklungen gingen jedoch mit der Verbreitung von falschen Mythen und Missverständnissen einher, die humane und ökonomische Ressourcen konsumieren sowie das klinische Denken und – nicht zuletzt – den Patienten gefährden. Das Ziel dieses Artikels ist es daher, eine Übersicht über typische Beispiele von falschen Dogmen über in der Notfallmedizin häufig verwendete Laborwerte zu geben.Improvements in understanding human physiology and technical advances have contributed to the widespread use of laboratory diagnostics in patient work-up. However, this evolution in laboratory diagnostics was accompanied by the spread of false myths and misconceptions – consuming human and economic resources – and endangering clinical reasoning and especially patients. The aim of this article is therefore to provide an overview on some typical examples of false dogmata about frequently used values in emergency medicine laboratory diagnostics.La compréhension avancée de la physiologie humaine et le progrès technologique ont contribué à une large utilisation des valeurs laboratoires pour l’approche diagnostique du eatient. Cette évolution, néanmoins, a été accompagnée par une prolifération de mythes et de malentendus. Cela consume des ressources humaines et économiques, et met au risque poar le raisonnement clinique et le patient. Le but de cet article est ainsi de présenter un bref aperçu des dogmes les plus fréquents rencontrés sur le plan du diagnostic laboratoire de la médicine d’urgence

Visusstörungen in der Tumordiagnostik – Aderhautmetastasen

Choroidal metastasis represents the most common type of intraocular malignancy and preferably involves the posterior uveal tract. Breast and lung cancer - known or so far undiagnosed - are most frequently identified as the underlying tumor disease. The majority of patients diagnosed with uveal metastasis have additional metastatic manifestations elsewhere, so re-staging before treatment is recommended. The importance of a multidisciplinary approach is obvious. Early diagnosis and timely initiation of treatment are mandatory in case of vision-threatening situations. External beam radiation remains the therapy of choice. Overall survival of patients with uveal metastasis is limited, averaging six to twelve months. The other eye is frequently enough affected as well, justifying regular ophthalmologic follow-up during the further course of the disease.Eine Metastase eines Karzinoms ist der häufigste intraokuläre Tumor, und sie lokalisiert sich meist im Bereich der posterioren Uvea. Als Primärtumor findet man vorzugsweise ein (bekanntes oder unbekanntes) Mammakarzinom oder ein Bronchialkarzinom. Die überwiegende Mehrheit der Patienten hat bei Diagnose von Aderhautmetastasen weitere Metastasen, so dass ein Re-Staging sinnvoll sein kann. Die Notwendigkeit zur interdisziplinären Betreuung aufgrund der Lokalisation ist offensichtlich. Bei Visusbedrohung sind schnelle Diagnostik und Einleitung der Therapie entscheidend. Eine externe Strahlentherapie ist die Methode der Wahl. Die Überlebenszeit von Patienten mit Aderhautmetastasen ist kurz und beträgt median sechs bis zwölf Monate. Da auch das Partnerauge von Aderhautmetastasen betroffen sein kann, sind aus diesem Grund ophthalmologische Verlaufskontrollen sinnvoll

What vision loss might bring to light

We report a case of a 36-year old patient who suffered from a unilateral painless loss of vision. Ophthalmological examination in the context of a highly reactive syphilis serology revealed an acute syphilitic posterior placoide chorioretinitis (ASPPC). Additional clinical findings were a mucosal lesion on the upper lip, consistent with a plaque opaline and an alopecia specifica as manifestation of secondary syphilis. Treatment consisted in 6x 4 Mio. IE Penicillin G for 14 days and 50 mg Prednison for five days to prevent a Jarisch Herxheimer reaction. The diagnostic measures, therapy and follow up of syphilis, focusing on ocular involvement, are described.Eine 36-jährige Patientin, wurde aufgrund einer einseitigen Visusminderung vorstellig. Die ophthalmologische Untersuchung, im Kontext einer hochreaktiven Syphilis-Serologie, zeigte eine akute syphilitische plakoide Chorioretinitis. Mit einer Plaque opaline der Mundschleimhaut und mottenfrassähnlicher Alopezie lag klinisch eine sekundäre Syphilis mit Augenbeteiligung vor. Die Behandlung wurde mit 6x 4 Mio. IE Penicillin G während 14 Tagen und Prednison 50 mg während fünf Tagen durchgeführt. Anhand dieses Falles gehen wir auf die Diagnostik, Therapie und Nachkontrolle der Syphilis mit okulärer Beteiligung ein