Negative predictive value of the FebriDx host response point-of-care test in patients presenting to a single Australian emergency department with suspected COVID-19: an observational diagnostic accuracy study

Objectives
To determine the negative predictive value (NPV) of the FebriDx point-of-care host response device in patients presenting with symptoms suggestive of COVID-19 infection in a mostly immunised Australian emergency department (ED) population during the late 2021 phase of the COVID-19 pandemic.

Design
Observational diagnostic accuracy study comparing FebriDx point-of-care test to SARS-CoV-2 PCR.

Setting
An ED in Melbourne, Australia, with 63 000 annual presentations in 2021.

Participants
Patients aged 16 and over who met the Victorian Department of Health case definition for suspected COVID-19 infection PCR testing. Patients meeting any of the following criteria were excluded: 14 days prior to testing; current immunosuppressive or interferon therapy; live immunisation within the last 30 days; fever lasting >7 days; antibiotic or antiviral use in the preceding 14 days; experience of major trauma, major surgical intervention or severe burns within the last 30 days.

Primary and secondary outcome measures
COVID-19 PCR results (detected, not detected) and FebriDx results (bacterial positive, viral negative, viral positive).

Results
94 participants were enrolled (female: 46; male: 48), 34% of participants (tested positive for COVID-19 according to PCR results, with a background incidence among all adult ED attenders of 2.5%. The sensitivity of FebriDx for detection of COVID-19 was 56% (95% CI 40% to 100%) and specificity was 92% (95% CI 84% to 100%). For the population tested, this resulted in an NPV of 80% (95% CI 71% to 100%) and a positive predictive value of 78% (95% CI 60% to 100%).

Conclusions
In the context of a population with low COVID-19 infection rates, an evolved variant of COVID-19 and a very high community COVID-19 vaccination rate, FebriDx demonstrated reduced sensitivity and NPV relative to results from earlier international tests. These contextual factors should be considered during any attempt to generalise the current results.

Trial registration number
ACTRN12620001029987 (Australian Clinical Trials).

Leggi
Dicembre 2022

Time without PSA recurrence after radical prostatectomy as a predictor of future biochemical recurrence, metastatic disease and prostate cancer death: a prospective Scandinavian cohort study

Objective
Although surveillance after radical prostatectomy routinely includes repeated prostate specific antigen (PSA)-testing for many years, biochemical recurrence often occurs without further clinical progression. We therefore hypothesised that follow-up can be shortened for many patients without increasing the risk of prostate cancer death. We investigated the long-term probabilities of PSA recurrence, metastases and prostate cancer death in patients without biochemical recurrence five and 10 years after radical prostatectomy.

Design
Prospective cohort study. Stratification by Gleason score (≤3+4=7 or ≥4+3=7), pathological tumour stage (pT2 or ≥pT3) and negative or positive surgical margins.

Setting
Between 1989 and 1998, 14 urological centres in Scandinavia randomised patients to the Scandinavian Prostate Cancer Group study number 4 (SPCG-4) trial.

Participation
All 306 patients from the SPCG-4 trial who underwent radical prostatectomy within 1 year from inclusion were eligible. Four patients were excluded due to surgery-related death (n=1) or salvage radiotherapy or hormonal treatment within 6 weeks from surgery (n=3).

Primary outcome measures
Cumulative incidences and absolute differences in metastatic disease and prostate cancer death.

Results
We analysed 302 patients with complete follow-up during a median of 24 years. Median preoperative PSA was 9.8 ng/mL and median age was 65 years. For patients without biochemical recurrence 5 years after radical prostatectomy the 20-year probability of biochemical recurrence was 25% among men with Gleason score ≤3+4=7 and 57% among men with Gleason score ≥4+3=7; the probabilities for metastases were 0.8% and 17%; and for prostate cancer death 0.8% and 12%, respectively. The long-term probabilities were higher for pT ≥3 versus pT2 and for positive versus negative surgical margins. Limitations include small size of the cohort.

Conclusion
Many patients with favourable histopathology without biochemical recurrence 5 years after radical prostatectomy could stop follow-up earlier than 10 years after radical prostatectomy.

Leggi
Dicembre 2022

Sarcopenia and coexistent risk factors detected using the 'Yubi-wakka (finger-ring) test in adults aged over 65 years in the public annual health check-up in Tama City, Tokyo: a cross-sectional study

Objectives
To examine the positive rate of sarcopenia using the ‘Yubi-wakka’ (finger-ring) test and associated risk factors among adults aged 65 years and older.

Design
Cross-sectional study.

Setting
We used the Yubi-wakka test, which has been developed and validated as a predictor of sarcopenia, frailty, disability and mortality. A positive test result is indicated by a smaller calf circumference than the finger-ring. The test was administered during annual health check-ups among residents of Tama City, Japan.

Participants
During the 2019 fiscal year, 12 894 individuals aged 65 years and older underwent the Yubi-wakka test at primary care clinics.

Interventions
Examinees conducted the test themselves in a seated position. They formed a ring around their calf using both thumbs and index fingers and judged whether their calf was larger, the same or smaller than their finger-ring.

Primary and secondary outcome measures
We compared anthropometric and serological data between the positive (smaller calf) and negative (larger calf) test result groups.

Results
The positive rate was 15.4% among men and 18.5% among women. The prevalence of a positive result was higher in those aged ≥80 years than in younger age groups in both sexes (men: 22.8%; women: 28.8%). Multivariate logistic regression analysis showed that a diagnosis of metabolic syndrome was a risk factor for detecting a positive test result in women aged 65–74 years (OR 3.445; 95% CI 1.44 to 8.29) and ≥75 years (OR 3.37; 95% CI 1.97 to 5.78).

Conclusions
Because the Japanese population is healthy and lives long, interventions against sarcopenia are important, especially for older adults aged >75 years. The presence of metabolic syndrome may be a risk factor for sarcopenia (as detected by the Yubi-wakka test) and future frailty, and requires closer attention, especially among women.

Leggi
Dicembre 2022

Using thoracic ultrasound to detect interstitial lung disease in patients with rheumatoid arthritis: a protocol for the diagnostic test accuracy AURORA study

Introduction
Pulmonary diseases are significant contributors to morbidity and mortality in patients with rheumatoid arthritis (RA). RA-associated interstitial lung disease (RA-ILD) may be prevalent in up to 30% and clinically evident in 10% of patients with RA. Feasible methods to detect concomitant ILD in RA are warranted. Our objective is to determine the diagnostic accuracy of thoracic ultrasound (TUS) for ILD in patients with RA with respiratory symptoms, by using chest high-resolution CT (HRCT) as the reference standard. Further, we aim to evaluate the diagnostic accuracy for the promising blood biomarkers surfactant protein-D and microfibrillar-associated protein 4 in the detection of ILD in this group of patients.

Methods and analysis
By use of a standardised 14 zone protocol patients suspected of having RA-ILD will undergo TUS as index test performed by a junior resident in rheumatology (BKS), who is certified by the European Respiratory Society in performing TUS assessments. Participants form a consecutive series of up to 80 individuals in total. The anonymised TUS images will be stored and scored by the junior resident as well as two senior rheumatologists, who have received training in TUS, and a TUS-experienced pulmonologist. HRCT will be used as the gold standard for ILD diagnosis (reference standard). The two basic measures for quantifying the diagnostic test accuracy of the TUS test are the sensitivity and specificity in comparison to the HRCT.

Ethics and dissemination
Data will be collected and stored in the Research Electronic Data Capture database. The study is approved by the Committees on Health Research Ethics and the Danish Data Protection Agency. The project is registered at clinicaltrials.gov (NCT05396469, pre-results) and data will be published in peer-reviewed journals.

Leggi
Dicembre 2022

Technical evaluation and usability of a quantitative G6PD POC test in cord blood: a mixed-methods study in a low-resource setting

Objectives
New point-of-care (POC) quantitative G6PD testing devices developed to provide safe radical cure for Plasmodium vivax malaria may be used to diagnose G6PD deficiency in newborns at risk of severe neonatal hyperbilirubinaemia, improving clinical care, and preventing related morbidity and mortality.

Methods
We conducted a mixed-methods study analysing technical performance and usability of the ‘STANDARD G6PD’ Biosensor when used by trained midwives on cord blood samples at two rural clinics on the Thailand–Myanmar border.

Results
In 307 cord blood samples, the Biosensor had a sensitivity of 1.000 (95% CI: 0.859 to 1.000) and a specificity of 0.993 (95% CI: 0.971 to 0.999) as compared with gold-standard spectrophotometry to diagnose G6PD-deficient newborns using a receiver operating characteristic (ROC) analysis-derived threshold of ≤4.8 IU/gHb. The Biosensor had a sensitivity of 0.727 (95% CI: 0.498 to 0.893) and specificity of 0.933 (95% CI: 0.876 to 0.969) for 30%–70% activity range in girls using ROC analysis-derived range of 4.9–9.9 IU/gHb. These thresholds allowed identification of all G6PD-deficient neonates and 80% of female neonates with intermediate phenotypes.
Need of phototherapy treatment for neonatal hyperbilirubinaemia was higher in neonates with deficient and intermediate phenotypes as diagnosed by either reference spectrophotometry or Biosensor.
Focus group discussions found high levels of learnability, willingness, satisfaction and suitability for the Biosensor in this setting. The staff valued the capacity of the Biosensor to identify newborns with G6PD deficiency early (‘We can know that early, we can counsel the parents about the chances of their children getting jaundice’) and at the POC, including in more rural settings (‘Because we can know the right result of the G6PD deficiency in a short time, especially for the clinic which does not have a lab’).

Conclusions
The Biosensor is a suitable tool in this resource-constrained setting to identify newborns with abnormal G6PD phenotypes at increased risk of neonatal hyperbilirubinaemia.

Leggi
Dicembre 2022