Effectiveness of contact tracing apps for SARS-CoV-2: a rapid systematic review
Open Access
- 12 July 2021
- Vol. 11 (7), e050519
- https://doi.org/10.1136/bmjopen-2021-050519
Abstract
Objective To systematically review evidence on effectiveness of contact tracing apps (CTAs) for SARS-CoV-2 on epidemiological and clinical outcomes. Design Rapid systematic review. Data sources EMBASE (OVID), MEDLINE (PubMed), BioRxiv and MedRxiv were searched up to 28 October 2020. Study selection Studies, both empirical and model-based, assessing effect of CTAs for SARS-CoV-2 on reproduction number (R), total number of infections, hospitalisation rate, mortality rate, and other epidemiologically and clinically relevant outcomes, were eligible for inclusion. Data extraction Empirical and model-based studies were critically appraised using separate checklists. Data on type of study (ie, empirical or model-based), sample size, (simulated) time horizon, study population, CTA type (and associated interventions), comparator and outcomes assessed, were extracted. The most important findings were extracted and narratively summarised. Specifically for model-based studies, characteristics and values of important model parameters were collected. Results 2140 studies were identified, of which 17 studies (2 empirical, 15 model-based studies) were eligible and included in this review. Both empirical studies were observational (non-randomised) studies and at high risk of bias, most importantly due to risk of confounding. Risk of bias of model-based studies was considered low for 12 out of 15 studies. Most studies demonstrated beneficial effects of CTAs on R, total number of infections and mortality rate. No studies assessed effect on hospitalisation. Effect size was dependent on model parameters values used, but in general, a beneficial effect was observed at CTA adoption rates of 20% or higher. Conclusions CTAs have the potential to be effective in reducing SARS-CoV-2 related epidemiological and clinical outcomes, though effect size depends on other model parameters (eg, proportion of asymptomatic individuals, or testing delays), and interventions after CTA notification. Methodologically sound comparative empirical studies on effectiveness of CTAs are required to confirm findings from model-based studies.Funding Information
- Rijksinstituut voor Volksgezondheid en Milieu (Not applicable)
This publication has 25 references indexed in Scilit:
- Universal Shelter-in-Place Versus Advanced Automated Contact Tracing and Targeted IsolationMayo Clinic Proceedings, 2020
- Impact of delays on effectiveness of contact tracing strategies for COVID-19: a modelling studyThe Lancet Public Health, 2020
- An Agent Based Modeling of COVID-19: Validation, Analysis, and RecommendationsPublished by Cold Spring Harbor Laboratory ,2020
- Effectiveness of isolation, testing, contact tracing, and physical distancing on reducing transmission of SARS-CoV-2 in different settings: a mathematical modelling studyThe Lancet Infectious Diseases, 2020
- Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracingScience, 2020
- Containing COVID-19 Among 627,386 Persons in Contact With the Diamond Princess Cruise Ship Passengers Who Disembarked in Taiwan: Big Data AnalyticsJournal of Medical Internet Research, 2020
- Risk assessment via layered mobile contact tracing for epidemiological interventionPublished by Cold Spring Harbor Laboratory ,2020
- Extensions of the SEIR Model for the Analysis of Tailored Social Distancing and Tracing Approaches to Cope with COVID-19Published by Cold Spring Harbor Laboratory ,2020
- Digital Herd Immunity and COVID-19Published by Cold Spring Harbor Laboratory ,2020