Evidence of the effectiveness of travel-related measures during the early phase of the COVID-19 pandemic: a rapid systematic review

  1. Karen Ann Grépin
  2. Tsi-Lok Ho
  3. Zhihan Liu
  4. Summer Marion
  5. Julianne Piper
  6. Catherine Z Worsnop
  7. Kelley Lee

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Abstract

To review the effectiveness of travel measures implemented during the early stages of the COVID-19 pandemic to inform changes on how evidence is incorporated in the International Health Regulations (2005) (IHR).

Design

We used an abbreviated Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols to identify studies that investigated the effectiveness of travel-related measures preprinted or published by 1 June 2020.

Results

We identified 29 studies, of which 26 were modelled. Thirteen studies investigated international measures, while 17 investigated domestic measures (one investigated both). There was a high level of agreement that the adoption of travel measures led to important changes in the dynamics of the early phases of the COVID-19 pandemic: the Wuhan measures reduced the number of cases exported internationally by 70%–80% and led to important reductions in transmission within Mainland China. Additional travel measures, including flight restrictions to and from China, may have led to additional reductions in the number of exported cases. Few studies investigated the effectiveness of measures implemented in other contexts. Early implementation was identified as a determinant of effectiveness. Most studies of international travel measures did not account for domestic travel measures thus likely leading to biased estimates.

Conclusion

Travel measures played an important role in shaping the early transmission dynamics of the COVID-19 pandemic. There is an urgent need to address important evidence gaps and also a need to review how evidence is incorporated in the IHR in the early phases of a novel infectious disease outbreak.

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  1. Version published to 10.1136/bmjgh-2020-004537
  2. ScreenIT

    SciScore for 10.1101/2020.11.23.20236703: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    For pre-print papers, we searched the BioRxiv and MedRxiv servers, which offer limited search functionality, using the following keywords in the title field: travel*, flight*, airline*, border*, airport*, passenger or air traffic.
    BioRxiv
    suggested: (bioRxiv, RRID:SCR_003933)
    We used the same travel-related keywords to search the WHO’s COVID-19 global research database but did not impose a COVID-19 search term as theoretically all articles in this database were on this topic.b For published papers, we searched PubMed with the following search strategy: studies must include at least one COVID-19 keyword mentioned above or one of the location-specific terms mentioned above combined with either (“severe acute respiratory” OR pneumonia AND outbreak
    PubMed
    suggested: (PubMed, RRID:SCR_004846)

    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:
    In addition, it is also possible that some of the travel-related measures adopted (e.g. screening) could have actually led to increased detection of cases,46 which could further complicate the ability of studies to evaluate effectiveness as the measurement of the outcome is influenced by the intervention itself and few studies acknowledged this limitation. Finally, while this study identified a relatively large number of studies, we assess the quality of these studies overall to be low. Almost all of the studies identified in this review were modelled studies, and therefore the results depend upon important parameter assumptions, which varied considerably. Given the rapidly evolving and dynamic nature of the pandemic, it is unclear how close to reality these assumptions were. Comparability across the studies is also undermined by a lack of standardized terminology. Furthermore, few studies attempted to isolate the potential effect of international travel-related measures from a range of domestic measures implemented concurrently, as well as from other social, political, or economic characteristics of the implementing or target locations or populations. This systematic review also has several important limitations of its own. First, while we aimed to be systematic in our search strategy as well as inclusion criteria, the rapidly expanding literature on COVID-19 pandemic almost certainly means that we likely overlooked some relevant studies. Second, although we aimed to focus o...

    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.
    • No protocol registration statement was detected.

    About SciScore

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  3. Version published to 10.1101/2020.11.23.20236703v1 on medRxiv