Public health effectiveness of digital contact tracing in the COVID-19 pandemic: A systematic review of available data

Main Article Content

Clara Mazza
Daniela Girardi
Leandro Gentile
Maddalena Gaeta
Carlo Signorelli
Anna Odone

Keywords

Digital Contact Tracing, Digital Contact Tracing Effectiveness, Covid-19

Abstract

Background and aim


Contact tracing is a key element of epidemiologic investigation and active surveillance during infectious diseases outbreaks. Digital contact tracing (DCT) are new technologies that have been increasingly adopted in different countries to support conventional contact tracing efforts to control the COVID-19 pandemic. However, scant evidence is available on its public health effectiveness. We applied the Indicator Framework issued in 2021 jointly by the World Health Organization (WHO) and the European Centre for Disease Prevention and Control (ECDC) to assess the available evidence on DCT adoption and impact in the context of the COVID-19 pandemic.


Methods


We carried out a systematic review following the PRISMA guidelines (Prospero registration number: CRD42021253662) to retrieve, pool, and critically appraise studies published in English from November 2019 to April 2021. We excluded mathematical models of effectiveness. Only studies representative of the general population or specific populations were included . In line with the WHO-ECDC indicator framework, outcomes of interest were grouped in indicators of: i) DCT use, ii) DCT success, and iii) DCT performance.


Results


We identified 1.201 citations searching the PubMed, Embase, Web of Science and The Cochrane Library. After screening, 10 studies were included. All included studies reported measures of DCT use, varying widely by study population and setting (percentage of DCT apps download from 0.01% to 58.3% in included studies). Almost no data quantified an association between DCT adoption rate and infection transmission at the community level.  Only one reported measures of DCT success (ratio of exposure notifications received to positive test results entered), while no studies were retrieved reporting measures of DCT performance.


Conclusions


DCT has large potential to control epidemics. Its adoption is hindered by several normative, technical and acceptance barriers in different regions and countries. Our review shows that while some evidence is available on its adoption and use in selected settings, very scant data is available on its effectiveness in the fight against COVID-19. As digitalization provides new tools for infection control at the population level, solid research is needed to quantify the public health effects of their application.

Abstract 1031 | PDF Downloads 473

References

1. Braithwaite I, Callender T, Bullock M, Aldridge RW. Automated and partly automated contact tracing: a systematic review to inform the control of COVID-19. Lancet Digit Health. 2020 Aug 19;2(11):e607–e621.
2. Signorelli C, Scognamiglio T, Odone A. COVID-19 in Italy: impact of containment measures and prevalence estimates of infection in the general population. Acta Biomed. 2020 Apr 10;91(3-S):175–179.
3. Coronavirus disease (COVID-19): Contact tracing [Internet]. 2020 [cited 2021 Aug 31]. Available from: https://www.who.int/news-room/q-a-detail/coronavirus-disease-covid-19-contact-tracing
4. Infection prevention and control: Contact tracing [Internet]. 2017 [cited 2021 Aug 31]. Available from: https://www.who.int/news-room/q-a-detail/contact-tracing
5. Garry M, Hope L, Zajac R, Verrall AJ, Robertson JM. Contact tracing: A memory task with consequences for public health. Perspect Psychol Sci. 2021 Jan;16(1):175–187.
6. Tracking COVID-19: Contact Tracing in the Digital Age [Internet]. 2020 [cited 2021 Aug 31]. Available from: https://www.who.int/news-room/feature-stories/detail/tracking-covid-19-contact-tracing-in-the-digital-age
7. World Health Organization (WHO), ECDC. Indicator framework to evaluate the public health effectiveness of digital proximity tracing solutions. 2021 Jun 28;
8. Lockey S, Edwards MR, Hornsey MJ, Gillespie N, Akhlaghpour S, Colville S. Profiling adopters (and non-adopters) of a contact tracing mobile application: Insights from Australia. Int J Med Inform. 2021 Feb 9;149:104414.
9. Thomas R, Michaleff ZA, Greenwood H, Abukmail E, Glasziou P. Concerns and Misconceptions About the Australian Government’s COVIDSafe App: Cross-Sectional Survey Study. JMIR Public Health Surveill. 2020 Nov 4;6(4):e23081.
10. von Wyl V, Höglinger M, Sieber C, et al. Drivers of Acceptance of COVID-19 Proximity Tracing Apps in Switzerland: Panel Survey Analysis. JMIR Public Health Surveill. 2021 Jan 6;7(1):e25701.
11. Salathé M, Althaus C, Anderegg N, et al. Early evidence of effectiveness of digital contact tracing for SARS-CoV-2 in Switzerland. Swiss Med Wkly. 2020 Dec 14;150:w20457.
12. Kendall M, Milsom L, Abeler-Dörner L, et al. Epidemiological changes on the Isle of Wight after the launch of the NHS Test and Trace programme: a preliminary analysis. Lancet Digit Health. 2020 Dec;2(12):e658–e666.
13. Montagni I, Roussel N, Thiébaut R, Tzourio C. Health Care Students’ Knowledge of and Attitudes, Beliefs, and Practices Toward the French COVID-19 App: Cross-sectional Questionnaire Study. J Med Internet Res. 2021 Mar 3;23(3):e26399.
14. Sharma N, Basu S, Sharma P. Sociodemographic determinants of the adoption of a contact tracing application during the COVID-19 epidemic in Delhi, India. Health Policy and Technology. 2021 Mar;100496.
15. Elkhodr M, Mubin O, Iftikhar Z, et al. Technology, Privacy, and User Opinions of COVID-19 Mobile Apps for Contact Tracing: Systematic Search and Content Analysis. J Med Internet Res. 2021 Feb 9;23(2):e23467.
16. Garrett PM, White JP, Lewandowsky S, et al. The acceptability and uptake of smartphone tracking for COVID-19 in Australia. PLoS One. 2021 Jan 22;16(1):e0244827.
17. Kawakami N, Sasaki N, Kuroda R, Tsuno K, Imamura K. The Effects of Downloading a Government-Issued COVID-19 Contact Tracing App on Psychological Distress During the Pandemic Among Employed Adults: Prospective Study. JMIR Ment Health. 2021 Jan 12;8(1):e23699.
18. Grekousis G, Liu Y. Digital contact tracing, community uptake, and proximity awareness technology to fight COVID-19: a systematic review. Sustainable Cities and Society. 2021 Aug;71:102995.
19. Abueg M, Hinch R, Wu N, et al. Modeling the effect of exposure notification and non-pharmaceutical interventions on COVID-19 transmission in Washington state. npj Digital Med. 2021 Mar 12;4(1):49.
20. Currie DJ, Peng CQ, Lyle DM, Jameson BA, Frommer MS. Stemming the flow: how much can the Australian smartphone app help to control COVID-19? Public Health Res Pract. 2020 Jun 30;30(2).
21. Horstmann KT, Buecker S, Krasko J, Kritzler S, Terwiel S. Who does or does not use the “Corona-Warn-App” and why? Eur J Public Health. 2021 Feb 1;31(1):49–51.
22. Frascella B, Oradini-Alacreu A, Balzarini F, Signorelli C, Lopalco PL, Odone A. Effectiveness of email-based reminders to increase vaccine uptake: a systematic review. Vaccine. 2020 Jan 16;38(3):433–443.
23. Odone A, Buttigieg S, Ricciardi W, Azzopardi-Muscat N, Staines A. Public health digitalization in Europe. Eur J Public Health. 2019 Oct 1;29(Supplement_3):28–35.
24. Balzarini F, Frascella B, Oradini-Alacreu A, et al. Does the use of personal electronic health records increase vaccine uptake? A systematic review. Vaccine. 2020 Aug 27;38(38):5966–5978.
25. Azzopardi-Muscat N, Ricciardi W, Odone A, Buttigieg S, Zeegers Paget D. Digitalization: potentials and pitfalls from a public health perspective. Eur J Public Health. 2019 Oct 1;29(Supplement_3):1–2.