United States Government Accountability Office
Highlights of GAO-21-104622, a report to
congressional
addressees
September
2021
TECHNOLOGY ASSESSMENT
Exposure Notification
Benefits and Challenges of Smartphone
Applications to Augment Contact Tracing
What GAO found
Exposure notification applications (apps)—which determine the proximity of users
and notify people who have been in close contact with another user who was likely
infectious—are expected to enhance the speed and reach of contact tracing and
help slow the spread of infectious diseases such as COVID-19. As of June 2021,
almost half (26/56) of U.S. states, territories, and the District of Columbia had
deployed an app for COVID-19, all using a system developed jointly by Google and
Apple (see figure). In the absence of a national app, states independently launched
apps, resulting in a staggered rollout over 10 months beginning in August 2020.
Map of deployment of exposure notification apps by U.S. states and territories, as of
June 2021
Reported app development costs for selected states varied, ranging from no cost
(provided by a nonprofit organization) to $700,000. Marketing costs for selected
states ranged from $380,000 to $3.2 million. Reported app download levels in the
selected states ranged from 200,000 to more than 2 million, as of June 2021.
GAO identified several challenges limiting app use and the ability of states and
others to determine whether the apps were effective:
Accuracy of
measurements
Technical limitations to measuring distance and exposure can result in
inaccurate exposure notifications.
Privacy and
security concerns
The public may lack confidence that its privacy is being protected, in
part, due to a lack of independent privacy and security assessments and
a lack of federal legal protections.
Adoption
States have faced challenges attracting public interest in downloading
and using an exposure notification app.
Verification code
delays
States faced challenges in promptly providing people who tested
positive for COVID-19 with a verification code necessary to notify other
close contacts of potential exposure using the app.
Evidence of
effectiveness
Limited data are available to evaluate the effectiveness of the apps.
Source: GAO. | GAO-21-104622
View GAO-21-104622. For more information,
contact
Karen L. Howard at (202) 512-6888
or
, [email protected]
or Vijay A. D’Souza, at
(
202) 512-6240, [email protected].
Why GAO did this study
With the emergence and rapid global
spread of COVID-19, smartphone
apps have been developed to
supplement manual contact tracing,
which is a public health measure used
to slow the spread of infectious
disease.
GAO was asked to conduct a
technology assessment of exposure
notification apps. This report
discusses (1) the benefits of exposure
notification apps; (2) the current level
of deployment in the U.S.; (3)
challenges affecting their use; and (4)
policy options that may help address
these challenges for future use.
To address these objectives, GAO
reviewed agency documentation, met
with officials from several federal
agencies, and conducted a review of
technical and policy literature. GAO
also interviewed representatives
from companies involved in the
development of exposure notification
apps, public health organizations,
federally funded research and
development centers, and academic
researchers. In addition, GAO
analyzed information from a selection
of states. GAO is identifying policy
options in this report.
GAO received technical comments on
a draft of this report from five federal
agencies and five organizations
included in the review, which it
incorporated as appropriate.
GAO developed the following four policy options that could help address challenges related to exposure notification apps. The policy
options identify possible actions by policymakers, which may include Congress, other elected officials, federal agencies, state and
local governments, and industry. See below for details of the policy options and relevant opportunities and considerations.
Policy Options to Help Address Challenges of Exposure Notification Apps for Future Use
Considerations
Research and Development
(report
page 41)
Policymakers could promote
research and development to
address technological
limitations.
increase accuracy, encouraging users to download
and use the apps.
• Research on technologies and architectures other
than those used by U.S. states could lead to
improvements.
• Partnerships with technology companies could spur
innovation and help with integrating improvements.
• The research needed may be costly.
• Improvements may not be cost-effective,
since existing apps may already be
sufficiently accurate.
• Research may result in apps that are not
functional for the next pandemic, since the
current apps were developed for COVID-19.
Privacy and Security
Standards and Practices
(report
page 42)
Policymakers
could promote
uniform privacy and security
standards and
practices for
exposure notification apps.
address real and perceived risks to the public’s data,
potentially increasing adoption.
• Standards developed by a broad coalition of
stakeholders could increase the likelihood of
stakeholder agreement and buy-in.
• Policymakers would need to balance the
need for privacy and security with the costs
of implementing standards and practices.
• Implementation of privacy requirements
may need to be flexible, since jurisdictions
could use different approaches.
• Standards and practices could be
challenging to oversee and enforce.
Best Practices (report page
43
)
Policymakers could
promote
best practices
for
approaches to
increasing
adoption
and to measure
the effectiveness of
exposure notification apps.
app adoption.
• Best practices could help state public health
authorities by providing information on procedures
and potential approaches for distributing
verification codes in a timely manner.
• Best practices could help public health authorities
establish a more rigorous way to measure the
extent of app use and any resulting improvements
• Best practices could require consensus from
many public- and private-sector
stakeholders, which can be time- and
resource-intensive.
• Current best practices may have limited
relevance to a future pandemic.
• In some cases, stakeholders may lack
sufficient information or the experience to
develop best practices.
National Strategy (report
page
44)
Policymakers could
collaborate
to enhance
the
pandemic national
s
trategy and promote a
coordinated approach
to the development
and
deployment of
exposure notification
apps
.
the underlying infrastructure and lessons
learned from COVID-19 could prompt faster
deployment of apps in the future.
• A future national marketing campaign with
cohesive and coherent messaging could result
in wider adoption.
• Policymakers could recommend a national app that
public health authorities could decide to use based
on their individual needs. A national app could add
more functions by integrating exposure notification
capabilities with test scheduling and vaccine
• A coordinated national approach would
likely have associated costs and require
sustained funding during the pandemic.
• Coordination of groups with divergent
perspectives and interests may pose
challenges to defining outcomes, measuring
performance, and establishing a leadership
approach.
• It is unclear whether potential users
would be more or less likely to trust a
national exposure notification app than
one developed by a state government.
Source: GAO. | GAO-21-104622