Determining the risk of developing symptomatic covid-19 infection after attending hospital for radiological examinations: controlled cohort study

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Abstract

OBJECTIVE

To determine whether brief attendance for outpatient radiological investigations is associated with increased risk of clinically significant coronavirus disease 2019 (covid-19) infection.

DESIGN

Observational cohort study with a historical control.

SETTING

2 large UK University Hospitals located in Nottingham and Cardiff.

PARTICIPANTS

All 47,340 patients who attended an outpatient radiology appointment at Nottingham University Hospitals and University Hospital of Wales during the first wave of the pandemic in 2020, and 70,655 patients that comprised the control cohort who attended for outpatient radiology the same period in 2019.

MAIN OUTCOME MEASURES

The risk of developing clinically significant covid-19 infection within 28-days of attending a radiological examination. Covid-19 infection rates for the 2020 cohort were compared against a control group who attended in 2019.

RESULTS

84 positive SARS-CoV-2 tests were temporally associated with 47,340 radiological examinations across two hospitals in 2020. This low infection rate was higher than the 2019 control cohort; OR 2.507 (1.766 – 3.559) and equates to an approximate 1 positive covid-19 infection per 1000 radiology investigations.

CONCLUSIONS

Our data suggests that attending hospitals for outpatient radiological investigations during the pandemic is associated with a very small absolute risk of acquiring clinically significant covid-19 infection. It is unlikely that this risk is directly attributable to radiology attendance, considering the reasons leading individuals to attend hospitals during the pandemic, the true attributable risk will likely be even lower.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04544176

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  1. SciScore for 10.1101/2021.03.08.21253143: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    RandomizationData Validation and Sensitivity Analysis: 100 randomly selected participants present in the 2020 datasets extracted by the NHS hospital analysts from Cardiff and Nottingham, were independently validated to confirm that patients attended face-to-face radiology investigations
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    No key resources detected.


    Results from OddPub: Thank you for sharing your data.


    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Our study does however have some limitations. In the early phase of the pandemic, covid-19 testing capacity was very small with limited community testing taking place. In our centres, PCR tests were restricted to hospital attendances and admissions. It is therefore possible that patients who attended hospital for outpatient radiology investigations might have subsequently experienced mild or asymptomatic covid-19 infection but were never tested. However, our methodology can be expected to have detected all cases of severe covid-19, requiring hospitalisation, which we feel is most relevant as it seems severe rather than asymptomatic disease drives patient fear of hospital attendance. It is also likely despite our study design attempting to match to some degree for comorbidity, that our results were influenced by residual cofounding. We suspect individuals attending in 2020, during the pandemic when many patients were avoiding hospitals, were likely to be at higher risk of covid-19 as they had more acute illnesses, with greater comorbidity and were probably exposed to more out of hospital care, compared to the 2019 control cohort. As these factors would increase the risk of severe infection with covid-19, they could lead to over-estimation of the covid-19 risk attributable to a single radiology attendance. The true risk therefore is likely to be below that which we report. Although we have not found a significantly increased risk of covid-19 infection in Nottingham, a small exc...

    Results from TrialIdentifier: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT04544176CompletedCOVID-19 Risk From Attending Outpatient Radiology Appointmen…


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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