Are surgical masks manufactured from sterilisation wrap safe?

BACKGROUND: Due to regional shortages some health services have proposed using surgical masks manufactured from sterilisation wrap. However, there has been little assessment of the safety of this practice. Therefore, we developed our own prototypes and evaluated whether they met regulatory standards. METHODS: Surgical mask prototypes were manufactured from two thickness grades of commercial sterilisation wrap. Safety was assessed in the context of regulatory standards. As it was not previously reported, we developed and performed differential pressure and synthetic blood penetration resistance experiments in accordance with official methodology. RESULTS: Bacterial filtration efficiency was comparable between sterilisation wrap and commercial surgical masks. Both prototypes met regulatory standards for synthetic blood resistance, whilst only our thinner mask fulfilled acceptable differential pressure ('breathability') thresholds. CONCLUSION: Acceptable barrier and breathability properties can be achieved with surgical masks produced from sterilisation wrap. Therefore, this may be a reasonable method to supplement stock if required. Unless there are shortages mandating alternatives, health-care workers should always use approved personal protective equipment.

COVID-MATCH65-A prospectively derived clinical decision rule for severe acute respiratory syndrome coronavirus 2.

OBJECTIVES: We report on the key clinical predictors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and present a clinical decision rule that can risk stratify patients for COVID-19. DESIGN, PARTICIPANTS AND SETTING: A prospective cohort of patients assessed for COVID-19 at a screening clinic in Melbourne, Australia. The primary outcome was a positive COVID-19 test from nasopharyngeal swab. A backwards stepwise logistic regression was used to derive a model of clinical variables predictive of a positive COVID-19 test. Internal validation of the final model was performed using bootstrapped samples and the model scoring derived from the coefficients, with modelling performed for increasing prevalence. RESULTS: Of 4226 patients with suspected COVID-19 who were assessed, 2976 patients underwent SARS-CoV-2 testing (n = 108 SARS-CoV-2 positive) and were used to determine factors associated with a positive COVID-19 test. The 7 features associated with a positive COVID-19 test on multivariable analysis were: COVID-19 patient exposure or international travel, Myalgia/malaise, Anosmia or ageusia, Temperature, Coryza/sore throat, Hypoxia-oxygen saturation < 97%, 65 years or older-summarized in the mnemonic COVID-MATCH65. Internal validation showed an AUC of 0.836. A cut-off of ≥ 1.5 points was associated with a 92.6% sensitivity and 99.5% negative predictive value (NPV) for COVID-19. CONCLUSIONS: From the largest prospective outpatient cohort of suspected COVID-19 we define the clinical factors predictive of a positive SARS-CoV-2 test. The subsequent clinical decision rule, COVID-MATCH65, has a high sensitivity and NPV for SARS-CoV-2 and can be employed in the pandemic, adjusted for disease prevalence, to aid COVID-19 risk-assessment and vital testing resource allocation.

Accuracy of Smartphone Camera Applications for Detecting Atrial Fibrillation: A Systematic Review and Meta-analysis.

Importance: Atrial fibrillation (AF) affects more than 6 million people in the United States; however, much AF remains undiagnosed. Given that more than 265 million people in the United States own smartphones (>80% of the population), smartphone applications have been proposed for detecting AF, but the accuracy of these applications remains unclear. Objective: To determine the accuracy of smartphone camera applications that diagnose AF. Data Sources and Study Selection: MEDLINE and Embase were searched until January 2019 for studies that assessed the accuracy of any smartphone applications that use the smartphone's camera to measure the amplitude and frequency of the user's fingertip pulse to diagnose AF. Data Extraction and Synthesis: Bivariate random-effects meta-analyses were constructed to synthesize data. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) of Diagnostic Test Accuracy Studies reporting guideline. Main Outcomes and Measures: Sensitivity and specificity were measured with bivariate random-effects meta-analysis. To simulate the use of these applications as a screening tool, the positive predictive value (PPV) and negative predictive value (NPV) for different population groups (ie, age ≥65 years and age ≥65 years with hypertension) were modeled. Lastly, the association of methodological limitations with outcomes were analyzed with sensitivity analyses and metaregressions. Results: A total of 10 primary diagnostic accuracy studies, with 3852 participants and 4 applications, were included. The oldest studies were published in 2016 (2 studies [20.0%]), while most studies (4 [40.0%]) were published in 2018. The applications analyzed the pulsewave signal for a mean (range) of 2 (1-5) minutes. The meta-analyzed sensitivity and specificity for all applications combined were 94.2% (95% CI, 92.2%-95.7%) and 95.8% (95% CI, 92.4%-97.7%), respectively. The PPV for smartphone camera applications detecting AF in an asymptomatic population aged 65 years and older was between 19.3% (95% CI, 19.2%-19.4%) and 37.5% (95% CI, 37.4%-37.6%), and the NPV was between 99.8% (95% CI, 99.83%-99.84%) and 99.9% (95% CI, 99.94%-99.95%). The PPV and NPV increased for individuals aged 65 years and older with hypertension (PPV, 20.5% [95% CI, 20.4%-20.6%] to 39.2% [95% CI, 39.1%-39.3%]; NPV, 99.8% [95% CI, 99.8%-99.8%] to 99.9% [95% CI, 99.9%-99.9%]). There were methodological limitations in a number of studies that did not appear to be associated with diagnostic performance, but this could not be definitively excluded given the sparsity of the data. Conclusions and Relevance: In this study, all smartphone camera applications had relatively high sensitivity and specificity. The modeled NPV was high for all analyses, but the PPV was modest, suggesting that using these applications in an asymptomatic population may generate a higher number of false-positive than true-positive results. Future research should address the accuracy of these applications when screening other high-risk population groups, their ability to help monitor chronic AF, and, ultimately, their associations with patient-important outcomes.

Systematic review with meta-analysis: sirolimus- or everolimus-based immunosuppression following liver transplantation for hepatocellular carcinoma.

BACKGROUND: Calcineurin-inhibitor immunosuppressants (tacrolimus and ciclosporin) have been associated with an exposure-related increase in tumour recurrence following liver transplantation for hepatocellular carcinoma (HCC). Conversely, mechanistic target of rapamycin (mTOR) inhibitors (sirolimus and everolimus) have been suggested to reduce recurrence rates and improve survival in this patient group. AIM: To clarify the potential benefit of mTOR-inhibitors in HCC transplant patients by comparing recurrence and survival outcomes with calcineurin-inhibitor-based immunosuppression. METHODS: A systematic review and meta-analysis was performed. The inclusion criteria were observational or interventional studies reporting the effect of early-initiated (<6 months post-transplant) mTOR-inhibitor-based immunosuppression on survival or tumour recurrence in patients transplanted with HCC, compared to a control of calcineurin-inhibitor-based therapy. RESULTS: Meta-analysis demonstrated that compared with calcineurin-inhibitor controls, recurrence-free-survival was significantly increased with mTOR-inhibitor-based therapy at 1-year (Risk-Ratio (RR): 1.09, 95% CI: 1.01-1.18) and 3-years (RR: 1.1, 95% CI: 1.01-1.21) post-transplant, with a nonsignificant increase at 5-years (RR: 1.15, 95% CI: 0.99-1.35). Overall survival was improved at 1-year (RR: 1.07, 95% CI: 1.02-1.12), 3-years (RR: 1.1, 95% CI: 1.02-1.19), and 5-years (RR: 1.18, 95% CI: 1.08-1.29). Recurrence-rate was lower in the mTOR-inhibitor arm (RR: 0.67, 95% CI: 0.56-0.82), with no significant increase in acute rejection (RR: 1.1, 95% CI: 0.94-1.28). CONCLUSIONS: mTOR-inhibitor-based immunosuppression may be a preferable option in patients transplanted with HCC. It improves recurrence-free-survival over at least three years and reduces the recurrence rate compared with standard calcineurin-inhibitor-based therapy, with no significant increase in the rate of acute rejection. Future research should clarify the effect in higher vs lower risk cohorts.

Urine cultures at the onset of febrile neutropenia rarely impact antibiotic management in asymptomatic adult cancer patients.

PURPOSE: There is a paucity of data regarding the utility of routine urine cultures in adults with febrile neutropenia (FN) without urinary symptoms receiving protocolised antibiotics. This is reflected by inconsistent recommendations in international and regional FN guidelines. We addressed this issue by retrospectively reviewing the impact of routine urine cultures on antibiotic management in haematology cancer inpatients at a tertiary hospital. METHODS: All haematology inpatients over a 5-year period (2011-2015) were retrospectively reviewed for episodes of FN (neutrophil count < 0.5 × 109/L and fever > 37.5 °C). For each episode, demographic data, urinary tract symptoms and signs (absence of which was termed 'asymptomatic'), urinalysis and urine culture results, antibiotic therapy and duration, and patient outcomes were collected. A urine culture was considered positive if > 105 colony forming units (CFU)/L were detected. Empiric antibiotic therapy for FN consisted of intravenous piperacillin/tazobactam in stable patients, with the addition of vancomycin and a single dose of gentamicin if systemically compromised. RESULTS: Four hundred and thirty-three episodes of FN were identified in 317 patients. Urine cultures were performed in 362 (84%) episodes. Cultures were positive in 9 of 48 (19%) symptomatic episodes versus 8 of 314 (2.5%) asymptomatic episodes (RR = 7.4, p < 0.0001). A change in antibiotic management due a positive urine culture occurred in only 5 episodes (1.4%): 3 of 48 (6.3%) symptomatic and 2 of 314 (0.6%) asymptomatic episodes respectively (RR = 9.8, p = 0.01). CONCLUSION: Routine urine cultures in FN patients without urinary symptoms who are already receiving protocolised broad spectrum antibiotics rarely impact subsequent antibiotic management.

Helicobacter pylori and low-dose aspirin ulcer risk: A meta-analysis.

BACKGROUND AND AIM: Owing to wide-spread use, low-dose aspirin (LDA) produces a substantial amount of peptic ulcer disease. Current guidelines are ambivalent about the need for Helicobacter pylori eradication to protect against LDA ulcers. This study aimed to determine, through meta-analysis, if (and by how much) infection alters the baseline risk of peptic ulcers during LDA therapy. METHODS: Literature screening was performed in MEDLINE and EMBASE from inception to May 2018. Original studies reporting prevalence or incidence of uncomplicated ulcers in LDA users were included. Ulcer endpoints needed to be specified separately, according to H. pylori infection status. Meta-analysis was performed in MIX 2.0 Pro. RESULTS: Ten cross-sectional studies and seven randomized controlled trials were included (n = 5964). The pooled odds ratios with 95% confidence intervals (CI) for the risk of LDA ulcers in H. pylori-positive versus H. pylori-negative individuals were 1.68 (95%CI 1.40-2.02) and 1.65 (95%CI 1.29-2.08) under fixed-effects and random-effects models, respectively. Heterogeneity among studies was minimal (I2  = 26.9%). After adjusting for the protective effects of antisecretory drugs, the odds ratios increased to 1.94 (95%CI 1.54-2.46). CONCLUSION: This analysis suggests that H. pylori increases the risk of LDA ulcers by almost 70% in a population where some were taking proton pump inhibitors and/or other acid suppressants. Without antisecretory drugs, the risk almost doubles. Clinically, these findings may support the use of a test-and-treat approach to H. pylori in LDA users, particularly those already at higher risk of developing peptic ulcers.

Prevalence and outcomes of incidental imaging findings: umbrella review.

OBJECTIVE: To provide an overview of the evidence on prevalence and outcomes of incidental imaging findings. DESIGN: Umbrella review of systematic reviews. DATA SOURCES: Searches of MEDLINE, EMBASE up to August 2017; screening of references in included papers. ELIGIBILITY CRITERIA: Criteria included systematic reviews and meta-analyses of observational studies that gave a prevalence of incidental abnormalities ("incidentalomas"). An incidental imaging finding was defined as an imaging abnormality in a healthy, asymptomatic patient or an imaging abnormality in a symptomatic patient, where the abnormality was not apparently related to the patient's symptoms. Primary studies that measured the prevalence of incidentalomas in patients with a history of malignancy were also considered in sensitivity analyses. RESULTS: 20 systematic reviews (240 primary studies) were identified from 7098 references from the database search. Fifteen systematic reviews provided data to quantify the prevalence of incidentalomas, whereas 18 provided data to quantify the outcomes of incidentalomas (13 provided both). The prevalence of incidentalomas varied substantially between imaging tests; it was less than 5% for chest computed tomography for incidental pulmonary embolism in patients with and without cancer and whole body positron emission tomography (PET) or PET/computed tomography (for patients with and without cancer). Conversely, incidentalomas occurred in more than a third of images in cardiac magnetic resonance imaging (MRI), chest computed tomography (for incidentalomas of thorax, abdomen, spine, or heart), and computed tomography colonoscopy (for extra-colonic incidentalomas). Intermediate rates occurred with MRI of the spine (22%) and brain (22%). The rate of malignancy in incidentalomas varied substantially between organs; the prevalence of malignancy was less than 5% in incidentalomas of the brain, parotid, and adrenal gland. Extra-colonic, prostatic, and colonic incidentalomas were malignant between 10% and 20% of the time, whereas renal, thyroid, and ovarian incidentalomas were malignant around a quarter of the time. Breast incidentalomas had the highest percentage of malignancy (42%, 95% confidence interval 31% to 54%). Many assessments had high between-study heterogeneity (15 of 20 meta-analyses with I2 >50%). CONCLUSIONS: There is large variability across different imaging techniques both in the prevalence of incidentalomas and in the prevalence of malignancy for specific organs. This umbrella review will aid clinicians and patients weigh up the pros and cons of requesting imaging scans and will help with management decisions after an incidentaloma diagnosis. Our results can underpin the creation of guidelines to assist these decisions. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: CRD42017075679.