Evidence map›Paper›PMID 33827852›Full record

ArticleCMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne2021

The mobility gap: estimating mobility thresholds required to control SARS-CoV-2 in Canada.

Kevin A Brown, Jean-Paul R Soucy, Sarah A Buchan, Shelby L Sturrock, Isha Berry, Nathan M Stall, Peter Jüni, Amir Ghasemi, Nicholas Gibb, Derek R MacFadden and 1 more

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.

0numbers the graph read from it
0cells of the map it votes in
10citing papers in PubMed
1.9field-weighted citation impact, top 14% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

10 citing papers in PubMed, 21 citations in OpenAlex.

  1. Rising out-of-hospital mortality in Canada during 2020‒2022: A striking impact observed among young adults.Canadian journal of public health = Revue canadienne de sante publique · 2025
    Article
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  5. National Influenza Annual Report, Canada, 2021-2022: A brief, late influenza epidemic.Canada communicable disease report = Releve des maladies transmissibles au Canada · 2022
    Article
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  7. Article
  8. Article
  9. Article
  10. Stringency of containment and closures on the growth of SARS-CoV-2 in Canada prior to accelerated vaccine roll-out.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2022
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors at 7 institutions in 2 countries.

Kevin A BrownPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont. kevin.brown@utoronto.ca nick.daneman@sunnybrook.ca.
Jean-Paul R SoucyPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Sarah A BuchanPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Shelby L SturrockPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Isha BerryPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Nathan M StallPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Peter JüniPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Amir GhasemiPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Nicholas GibbPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Derek R MacFaddenPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont.
Nick DanemanPublic Health Ontario (Brown, Buchan, Daneman); Dalla Lana School of Public Health (Brown, Soucy, Buchan, Sturrock, Berry), and The Institute for Health Policy, Management, and Evaluation (Stall, Jüni, Daneman), University of Toronto; Applied Health Research Centre, St. Michael's Hospital (Jüni); Sinai Health System and the University Health Network (Stall); Women's College Hospital (Stall); Department of Medicine (Stall, Daneman), University of Toronto, Toronto, Ont.; Communications Research Centre Canada (Ghasemi); Public Health Agency of Canada (Gibb); Ottawa Hospital Research Institute (MacFadden), Ottawa, Ont.; Division of Infectious Diseases (Daneman), Sunnybrook Research Institute, Toronto, Ont. kevin.brown@utoronto.ca nick.daneman@sunnybrook.ca.
St. Michael's Hospital · CAPublic Health Agency of Canada · CAPublic Health Ontario · CACommunications Research Centre Canada · CASt Michaels Hospital · GBUniversity Health Network · CAWomen's College Hospital · CA

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundNonpharmaceutical interventions remain the primary means of controlling severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) until vaccination coverage is sufficient to achieve herd immunity. We used anonymized smartphone mobility measures to quantify the mobility level needed to control SARS-CoV-2 (i.e., mobility threshold), and the difference relative to the observed mobility level (i.e., mobility gap).

methodsWe conducted a time-series study of the weekly incidence of SARS-CoV-2 in Canada from Mar. 15, 2020, to Mar. 6, 2021. The outcome was weekly growth rate, defined as the ratio of cases in a given week versus the previous week. We evaluated the effects of average time spent outside the home in the previous 3 weeks using a log-normal regression model, accounting for province, week and mean temperature. We calculated the SARS-CoV-2 mobility threshold and gap.

resultsAcross the 51-week study period, a total of 888 751 people were infected with SARS-CoV-2. Each 10% increase in the mobility gap was associated with a 25% increase in the SARS-CoV-2 weekly case growth rate (ratio 1.25, 95% confidence interval 1.20-1.29). Compared to the prepandemic baseline mobility of 100%, the mobility threshold was highest in the summer (69%; interquartile range [IQR] 67%-70%), and dropped to 54% in winter 2021 (IQR 52%-55%); a mobility gap was present in Canada from July 2020 until the last week of December 2020.

interpretationMobility strongly and consistently predicts weekly case growth, and low levels of mobility are needed to control SARS-CoV-2 through spring 2021. Mobility measures from anonymized smartphone data can be used to guide provincial and regional loosening and tightening of physical distancing measures.

Indexed as

CanadaCOVID-19COVID-19 TestingDisease Transmission, InfectiousFemaleForecastingHumansIncidenceInterrupted Time Series AnalysisMalePhysical DistancingPublic HealthQuarantine

Identifiers

PMID33827852
PMCPMC8101979
OpenAlexW3139547224

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.