Using Venn Diagrams to Evaluate Digital Contact Tracing: Panel Survey Analysis

Area of Science:

• Epidemiology
• Public Health Technology

Background:

• Infection spread mitigation relies on preventing non-household interactions.
• Digital proximity tracing apps offer faster, broader contact tracing than manual methods.
• Assessing user responses to exposure notifications informs app effectiveness in managing SARS-CoV-2.

Purpose of the Study:

• To demonstrate Venn diagrams for analyzing digital proximity tracing app contributions.
• To investigate the role of exposure notifications in curbing SARS-CoV-2 spread in Switzerland.

Main Methods:

• Assessed data from 4 survey waves (Dec 2020–Mar 2021) of Swiss residents.
• Categorized participants into non-users, app users, and app users receiving notifications.
• Applied Venn diagrams to assess app use, key performance indicators, and mitigative actions.

Main Results:

• 30% of users receiving exposure notifications tested positive for SARS-CoV-2.
• This rate is over 3 times higher than for users not receiving notifications (8%).
• Most users (75.9%) who received notifications took recommended actions like testing or calling hotlines.

Conclusions:

• Mitigative actions by users suggest digital proximity tracing apps can help curb SARS-CoV-2 spread.
• Venn diagrams provide a valuable tool for assessing app effectiveness at a population level.
• This approach aids researchers and health authorities in evaluating digital tracing tool performance.