Changes in ischemic stroke presentations and associated workflow during the first wave of the COVID-19 pandemic: A population study in Alberta, Canada

  1. Aravind Ganesh
  2. Jillian M. Stang
  3. Finlay A. McAlister
  4. Oleksandr Shlakhter
  5. Jessalyn K. Holodinsky
  6. Balraj Mann
  7. Michael D. Hill
  8. Eric E. Smith

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Abstract

Background

Pandemics may promote hospital avoidance among patients with emergencies, and added precautions may exacerbate treatment delays. There is a paucity of population-based data on these phenomena for stroke. We examined the effect of the COVID-19 pandemic on the presentation and treatment of ischemic stroke in an entire population.

Methods

We used linked provincial administrative data and data from the Quality Improvement and Clinical Research Alberta Stroke Program – a registry capturing stroke-related data on the entire population of Alberta(4.3 million)– to identify all patients presenting with stroke in the pre-pandemic(1-January-2016 to 27-February-2020, n=19,531) and pandemic(28-February-2020 to 30-August-2020, n=2,255) periods. We examined changes in thrombolysis and endovascular therapy(EVT) rates, workflow, and in-hospital outcomes.

Results

Hospitalizations/presentations for ischemic stroke dropped (weekly adjusted-incidence-rate-ratio[aIRR]:0.48, 95%CI:0.46-0.50, adjusted for age, sex, comorbidities, pre-admission care needs), as did population-level incidence of thrombolysis(aIRR:0.49,0.44-0.56) or EVT(aIRR:0.59,0.49-0.69). However, the proportions of presenting patients receiving acute therapies did not decline (e.g. thrombolysis:11.7% pre-pandemic vs 13.1% during-pandemic, aOR:1.02,0.75-1.38). Onset-to-door times were prolonged; EVT recipients experienced longer door-to-reperfusion times (median door-to-reperfusion:110-minutes, IQR:77-156 pre-pandemic vs 132.5-minutes, 99-179 during-pandemic; adjusted-coefficient:18.7-minutes, 95%CI:1.45-36.0). Hospitalizations were shorter but stroke severity and in-hospital mortality did not differ.

Interpretation

The first COVID-19 wave was associated with a halving of presentations and acute therapy utilization for ischemic stroke at a population level, and greater pre-hospital and in-hospital treatment delays. Our data can inform public health messaging and stroke care in current and future waves. Messaging should encourage attendance for emergencies and stroke systems should re-examine “code stroke” protocols to mitigate inefficiencies.

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  1. ScreenIT

    SciScore for 10.1101/2021.10.04.21264529: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: The study was approved by the University of Calgary Conjoint Health Research Ethics Board (REB20-0769).
    Consent: No informed consent was required.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power AnalysisStatistical Analyses: Based on our sample size calculations (Supplement), we needed at least 38 treated patients in the Pandemic period to achieve 80% power for identifying a 25% drop in treatment volume or times.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    All analyses were performed with STATA/MP 16.1.
    STATA/MP
    suggested: None

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Whereas a key strength of our study is that the data arise from an entire population with a coordinated and robust stroke system of care, a few limitations merit discussion. First, we cannot know to what extent observed delays or declines in presentations were related to difficulties calling for help or accessing medical services, versus pure hospital avoidance. Second, because the cohort was defined by ICD administrative data, strokes may have been misclassified in some cases; however, our data sources and case definitions have been validated in prior audits.18 Third, data on pre-hospital and in-hospital workflow were only available for patients who received acute stroke therapies, likely resulting in underestimation of delays, since patients presenting much later would be less likely to receive therapies like thrombolysis. Whereas both hospitals and paramedics adopted additional infection prevention precautions, we do not have specific data on why delays occurred in different settings. Fourth, we do not have longer-term outcome data on most patients in the pandemic era, so we could not assess downstream effects of observed delays; however, post-stroke outcomes are highly dependent on time-to-treatment.34 Fifth, our dataset did not contain the COVID-19 status of patients, so we do not know whether patients were managed differently based on their infectious state; however, all patients were managed as potentially infectious in the first 24-hours pending RT-PCR results. Furthe...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    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.
    • Thank you for including a protocol registration statement.

    Results from scite Reference Check: We found no unreliable references.

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  2. Version published to 10.1101/2021.10.04.21264529v1 on medRxiv