Optimisation of COVID-19 diagnostic pathways in acute hospital admissions to prevent nosocomial transmission.

INTRODUCTION: In the management of acute hospital admissions during the COVID-19 pandemic, safe patient cohorting depends on robust admission diagnostic strategies. It is essential that screening strategies are sensitive and rapid, to prevent nosocomial transmission of COVID-19 and maintain patient flow. METHODS: We retrospectively identified all COVID-19 positive and suspected cases at our institution screened by reverse transcription polymerase chain reaction (RT-PCR) between 4 April and 28 June 2020. Using RT-PCR positivity within 7 days as our reference standard, we assessed sensitivity and net-benefit of three admission screening strategies: single admission RT-PCR, composite admission RT-PCR and CXR and repeat RT-PCR with 48 h. RESULTS: RT-PCR single-test sensitivity was 91.5% (87.8%-94.4%) versus 97.7% (95.4%-99.1%) (p = 0.025) for RT-PCR/CXR composite testing and 95.1% (92.1%-97.2%) (p = 0.03) for repeated RT-PCR. Net-benefit was 0.83 for single RT-PCR versus 0.89 for RT-PCR/CXR and 0.87 for repeated RT-PCR at 0.02% threshold probability. CONCLUSION: The RT-PCR/CXR composite testing strategy was highly sensitive when screening patients at the point of hospital admission. Real-world sensitivity of this approach was comparable to repeat RT-PCR testing within 48 h; however, faster facilitating improved patient flow.

Routine molecular point-of-care testing for SARS-CoV-2 reduces hospital-acquired COVID-19.

OBJECTIVES: Risk of hospital-acquired COVID-19 (HA-COVID-19) infection is increased by cohorting infected and non-infected patients together in assessment areas, whist awaiting laboratory PCR results. Molecular point-of-care tests (mPOCT) reduce time to results and improve patient flow but the impact on HA-COVID-19 is unknown. METHODS: In this pre and post implementation study patients were evaluated across two time periods: March 1st to August 13th 2020, prior to the introduction of mPOCT in medical admissions areas, and 14th August 2020 to 1st April 2021, after mPOCT introduction. The primary outcome was proportion of HA-COVID-19 infection among all COVID-19 positive patients. Secondary outcome measures included time to SARS-CoV-2 results, length of time spent in the medical assessment area and comparison of local, regional and national proportions of HA-COVID-19. RESULTS: 1988 patients were admitted through the acute medicine admission cohorting area and tested for SARS-CoV-2 prior to introducing mPOCT and 4640 afterwards. Median (IQR) time to SARS-CoV-2 result was 6.5 (2.1-17.9) hours prior to introducing mPOCT and 1.0 (0.8-1.3) hours afterwards (p < 0.0001). Median (IQR) duration in the assessment cohort area was 12.0 (4.8-20.6) hours prior to introduction of POCT and 3.2 (2.0-5.6) hours afterwards (p < 0.0001). The proportion of hospital-acquired COVID-19 cases was 108 (16.5%) of 654 prior to introducing mPOCT compared with 168 (9.4%) of 1782 afterwards, (HR 0.55, 95%CI 0.43-0.70; p < 0.0001). In the period following the introduction of mPOCT up to 1st April 2021 the median proportion of HA-COVID-19 was 13.6% (95%CI 8.2-18.9%) locally, compared with 43.8% (95%CI 37.8-49.9%) for all acute NHS trusts regionally and 30.9% (95%CI 28.4-33.5%) for all NHS trusts nationally. CONCLUSIONS: Routine mPOCT for SARS-CoV-2 was associated with reduced time to results, time spent in admission cohort areas, and hospital-acquired COVID-19, compared to laboratory PCR.

Wave comparisons of clinical characteristics and outcomes of COVID-19 admissions - Exploring the impact of treatment and strain dynamics.

OBJECTIVES: Dexamethasone has now been incorporated into the standard of care for COVID-19 hospital patients. However, larger intensive care unit studies have failed to show discernible improvements in mortality in the recent wave. We aimed to investigate the impacts of these factors on disease outcomes in a UK hospital study. METHODS: This retrospective observational study reports patient characteristics, interventions and outcomes in COVID-19 patients from a UK teaching hospital; cohort 1, pre 16th June-2020 (pre-dexamethasone); cohort 2, 17th June to 30th November-2020 (post-dexamethasone, pre-VOC 202,012/01 as dominant strain); cohort 3, 1st December-2020 to 3rd March-2021 (during establishment of VOC202012/01 as the dominant strain). RESULTS: Dexamethasone treatment was more common in cohorts 2 and 3 (42.7% and 51.6%) compared with cohort 1 (2.5%). After adjusting for risk, odds of death within 28 days were 2-fold lower in cohort 2 vs 1 (OR:0.47,[0.27,0.79],p = 0.006). Mortality was higher cohort 3 vs 2 (20% vs 14%); but not significantly different to cohort 1 (OR: 0.86,[0.64, 1.15],p = 0.308). CONCLUSIONS: The real world finding of lower mortality following dexamethasone supports the published trial evidence and highlights ongoing need for research with introduction of new treatments and ongoing concern over new COVID-19 variants.