Mathematica partnered with the National Academy for State Health Policy and Ipsos to help the Centers for Disease Control and Prevention evaluate state and local case investigation and contact tracing implementation, people’s actions after being notified of COVID-19 infection or exposure, and case investigation and contact tracing programs’ ability to reach populations disproportionately affected by COVID-19.

The project was comprised of the following five studies:

Survey of people testing positive for COVID-19 or notified of exposure. We designed, administered, and analyzed a survey to better understand the experiences of people who tested positive for COVID-19 (cases) and those who were notified of potential exposure (contacts). Fielded with the Ipsos KnowledgePanel®, the survey featured a nationally representative sample of 22,514 of U.S. adults, 15,923 of which completed interviews. Of these, 9,269 met eligibility criteria and completed questions about actions taken after testing positive for COVID-19 or being informed of exposure to a case. 

Focus groups and interviews with community members. We also designed, implemented, and analyzed 33 focus groups and six one-on-one interviews with a total of 184 participants who self-identified as cases or contacts to better understand their experiences, including barriers to and facilitators for isolation and quarantine and their participation in case investigation and contact tracing. 

State and local data analysis. Mathematica compiled and analyzed data on local- and state-level case investigation and contact tracing activities to identify groups of health jurisdictions with similar underlying vulnerability to COVID-19, to describe patterns in key case investigation and contact tracing metrics among these groups over time, and to assess whether changes to key policies and practices helped contextualize and explain observed patterns. We used a range of publicly available data sources, including data compiled on a website hosted by the National Academy for State Health Policy, to understand the range of case investigation and contact tracing approaches that states have taken over the course of the pandemic and the ways in which states can support local health departments in this work. 

Interviews with staff. Mathematica conducted key informant interviews with state epidemiologists and case investigation and contact tracing leadership staff representing 43 state, local, and tribal jurisdictions to understand case investigation and contact tracing approaches, how these approaches changed over time, and lessons learned. 

Analysis of interview scripts. For a subset of those sites, we gathered and analyzed case investigation and contact tracing interview scripts from up to three points in time to better understand common themes and changes over time.

The project created a website that compiled all the publicly available information about states’ approaches to case investigation and contact tracing. This enabled sharing of knowledge in a way that was easily accessible and helped inform time-sensitive, high-stakes decision making.