Quick Response (QR) Codes as an Approach to Contact Tracing for COVID-19

Last Updated: November 18, 2020

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This Briefing Note was completed by the Evidence Synthesis Unit (Research, Analysis and Evaluation Branch, Ministry of Health) based on a literature search, as well as information provided by members of the COVID-19 Evidence Synthesis Network. Please refer to the Methods section for further information.


Contact tracing is a process that is used to identify, educate, and monitor individuals who have had close contact with someone who is infected with a virus, such as coronavirus disease 2019 (COVID-19); these individuals are at a higher risk of infection and transmission. Contact tracing can help individuals understand their risk and limit further spread of the virus. Quick response (QR) codes, barcodes that can be scanned by smartphones, are a type of location-based digital contract tracing approach. This briefing note provides a summary of the evidence and jurisdictional experiences using QR codes as contact tracing approaches to contain the COVID-19 pandemic.

*The full version of the Briefing Note including the Appendix and QR Code example can be accessed in the PDF file at the top of the page*

Key Findings

Context and Terminology

A study (May 27, 2020) on digital contact tracing for coronavirus disease 2019 (COVID-19) described traditional and digital contact tracing approaches, including the use of QR codes:

  • Traditional Contact Tracing: Public health officials interview an infected individual, identify contacts, and advise exposed contacts to self-monitor for symptoms, self-quarantine, or obtain medical evaluation and treatment. This approach has had success in reducing infection transmission in many epidemics, including severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and Ebola. However, limitations have become apparent during the COVID-19 pandemic. For example, traditional contact tracing is labour- and time-intensive, making it challenging to scale.
  • Digital Contact Tracing: Electronic information has the potential to address limitations of traditional contact tracing, such as scalability, notification delays, recall errors, and contact identification in public spaces.
    • Bluetooth-Based Approaches: Most COVID-19 contact tracing apps use Bluetooth signal strength to infer distance and define exposure status based on distance from and duration of proximity to an individual subsequently identified as infected.
    • Location-Based Approaches: These contact tracing approaches do not require Bluetooth. Instead, they use cell phone network data, Global Positioning System (GPS), Wi-Fi signals, and other smartphone sensors to identify the geolocations of users and proximity to infected individuals.
      • QR Codes: These are barcodes that can be scanned by phones and can be placed in public spaces (e.g., bus doors, store entrances), allowing users to log visited locations.

Supporting Evidence

This section summarizes scientific evidence and jurisdictional experiences regarding use of QR codes as an approach to contact tracing during the COVID-19 pandemic. In terms of jurisdictional experience, information is presented on China, Israel, New Zealand, Singapore, and Taiwan. Additional details about use of QR codes in these jurisdictions are provided in Table 2 Appendix, which is accessible in the full PDF File located at the top of the page. No information was identified about Ontario or other Canadian jurisdictions.

Scientific Evidence

  • While QR codes may be easy to deploy, six studies identified a number of challenges associated with their use in contact tracing approaches:
    • A research commentary (June 29, 2020) indicated that mobile phone solutions for quarantine enforcement can be bypassed if individuals leave their quarantine location without their devices. Self-reported surveys, such as those used in QR code systems, only work when individuals are symptomatic and report their symptoms accurately. However, these technological innovations could provide benefits when used in combination with other strategies.
    • A study (June 15, 2020) suggested that QR code-based apps have merit where they are required to be used by all patrons of a specific location or service – for instance, when these apps are managed by individual service providers and can be tied to some specific exchange (e.g., fare for public transport, ticket to enter a venue). They do not appear well-suited to population-based systems spanning multiple activities and locations. Bluetooth-based apps appear better suited to population-based systems where participation is optional.
    • A preprint systematic review (May 28, 2020) assessed 15 automated or partially-automated contact tracing approaches, one of which included a modelling study (April 7, 2020) of a Bluetooth-based smartphone app that scans QR codes at checkpoints. No evidence was identified on the effectiveness of automated contact tracing. However, four of seven included modelling studies found that controlling COVID-19 requires high population uptake of automated contact tracing apps (estimates from 56%-95%), typically alongside other control measures. Automated contact tracing has the potential to reduce transmission with sufficient population uptake and usage, but there is a need for well-designed effectiveness evaluations.
      • The modeling study (April 7, 2020) indicated that the primary concern with using QR codes is user adoption. Users may not be comfortable with an application that tracks their real-time location. Users may also become fatigued over time from having to scan entry/exit points and choose to discontinue or be dissuaded from participating at the onset. Under normal circumstances, these hurdles might deter most users; however, due to the impact of the pandemic, users may be motivated to overlook these inconveniences in light of alternative, more-invasive location tracking measures.
    • A report (May 15, 2020) from the School of Geographical Sciences and Urban Planning Spatial Analysis Research Center (Arizona State University) indicated that while QR code systems have high locational accuracy, the lack of automated detection can cause problems if users do not regularly scan codes, such as extensive false negatives.
    • A preprint study (April 27, 2020) noted that although QR codes are relatively easy to deploy, manual scanning of QR codes can become tiresome if an individual has to scan many times a day at different places. Without service personnel stationed at each QR code location, people may skip scanning the code.

International Scan

  • China, Israel, New Zealand, Singapore, and Taiwan use QR codes as part of their case management and contact tracing strategies for COVID-19:
    • Purpose: Ranges from: expanding case management and testing capacity (e.g., supporting manual contact tracing efforts), controlling people’s movements in public places, and notifying people if they contacted with infected people.
      • In addition to their use in supporting the response to public health emergencies (e.g., COVID-19) in China, personal QR codes have also been adapted to support the self-management of health conditions, health care services provision, and organizing major public events.
    • Method:
      • In Australia, China, Netherlands, New Zealand, and Singapore, users scan QR codes with their smartphones at entry/exit checkpoints of public venues to keep track of places visited and/or to verify permission to enter public venues based on their low- or high-risk COVID-19 profile.
      • In Israel, four stationary testing centres in major metropolitan areas and eight drive-in testing centres use QR codes to identify patients.
      • In Taiwan, travelers flying to Taiwan must complete a COVID-19 health declaration form upon arrival at an airport by scanning a QR code. Those with low-risk accelerate immigration clearance and those at high-risk must quarantine at home and are tracked through their mobile phone.
    • Locations Used: Ranges from: office buildings, shopping centres, transportation systems (e.g., taxis, buses, trains, airports), schools/universities, parks, hospitality sector (e.g., hotels, restaurants), hospitals, funeral homes, places of worship, and testing centres.
      • China and Singapore seem to have implemented comprehensive QR coding systems in almost all public settings across the country
    • Information Collected: Ranges from: name, national registration IDs, phone number, home address, email, self-reported health status, travel history, relationship to confirmed or suspected cases, and date of visit to public venue.
      • China and Taiwan use big data analytics for case management and contact tracing. China’s QR code database is derived from users’ self-reported information, government databases, and data from other sources across sectors (e.g., banking, public transportation, telecommunications). China’s government is also promoting the timely incorporation of nucleic acid and serum antibody test results and other population data in the QR code database. Taiwan integrated its national health insurance and immigration/customs databases with QR code scanning and online reporting of travel history and health symptoms.
    • Mandatory/Voluntary Use: Mandatory in Australia (within the hospitality sector), China, Singapore, and Taiwan, and voluntary in Netherlands and New Zealand. Unknown for Israel.
    • Governance: Governments authorize and oversee the contract tracing approach, often in partnership with technology companies who developed the QR code applications (e.g., Alibaba Group Holding and Tencent Holdings in China, Rush Digital in New Zealand).
    • Privacy: Singapore’s QR code system abides by the personal data protection act. New Zealand’s system was created in consultation with the Privacy Commissioner, has two-factor authentication, enables automatic deletion of information after 31 days, and enables sharing of information with government only after the user’s permission. In the Netherlands, the QR codes help track interactions with no unique identifier assigned to any individual user or their app. This decentralized infrastructure is designed to ensure users privacy, as the entire system is based on locally stored random numbers that cannot be traced back to individual users. In New South Wales, when COVID app data is downloaded from the National COVIDSafe Data Store by a state or territory health authority, it retains its status as COVID app data under the Privacy Act. Businesses and organizations that are required to collect customer details must: keep the name and mobile number or email address of the customer/visitor for at least 28 day. No information on privacy measures was identified for the other countries.
    • Challenges:
      • In China and New Zealand, reported challenges include: people’s lack of willingness to sign up for contact tracing apps or share private health data, inconsistent data compilation, lack of audible prompts for visually impaired users, inability to record in locations that do not use QR codes, and/or incomplete contact tracing mechanisms if too few businesses opt into hosting QR code posters in voluntary systems.
      • A study (May 27, 2020) noted that tracking based on QR codes is being used in China, but familiarity with QR codes is high due to their use in mobile payments. However, it is unclear whether the strategy could be adopted for Europe and North America.

Canadian Scan

No information identified

Ontario Scan

No information identified


Individual peer-reviewed articles and review articles were identified through PubMed, the Cochrane Library, and Google Scholar. Grey literature was identified through Google and relevant government websites. The search was limited to English sources and therefore may not capture the full extent of initiatives in non-English speaking countries. Full-text results extracted were limited to those available through Open Access or studies made available to the Ministry by our partners.

The COVID-19 Evidence Synthesis Network is comprised of groups specializing in evidence synthesis and knowledge translation. The group has committed to provide their expertise to provide high-quality, relevant, and timely synthesized research evidence about COVID-19 to inform decision makers as the pandemic continues. The following members of the Network provided evidence synthesis products that were used to develop this Evidence Synthesis Briefing Note:

  • Wang Q, Wilson MG, Waddell K, Lavis JN. (June 26, 2020) COVID-19 rapid query response #2: What is known from evidence and experiences in China about the use of QR codes in contact tracing for COVID-19? Hamilton: McMaster Health Forum.

This is version 2.0 of this Evidence Synthesis Briefing Note; the previous version was completed in July, 2020.