Measures
The dependent variable of this study is URE in COVID-19-related social media posts as indicated by Boolean phrases detecting linguistic markers for both URE and the subject matter (Supplemental Table 
Throughout this process, each keyword phrase and group were reviewed to assess the prevalence of false positives (e.g., “evidence” referring to forensic evidence required more complex search phrases to assess “research evidence” or “scientific evidence”). Ultimately, eight keyword categories were created and comprised of approximately 200 research phrases. The phrases allowed for examination of a larger amount of data than what could be coded manually, given the large present sample.

