Because of the urgent need to better understand the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission mechanism and clinical outcomes resulting from infection, health organizations and research institutes developed data collection instruments to assess coronavirus disease 2019 (COVID-19) symptoms, treatments, and associated impacts on behaviors and risks, treatment and outcomes, information available, psychosocial and mental health, and socioeconomic effects across demographic groups. The PhenX team developed the COVID-19 Protocol Library to share data collection instruments, methods, and protocols in use by investigators and to reduce proliferation of similar protocols. The Office of Behavioral and Social Sciences Research and the National Human Genome Research Institute sponsored the effort, in collaboration with the NIH Disaster Research Response Program. As the COVID-19 library was being established, crowdsourcing was used to identify key topics related to the pandemic, which formed the basis of the COVID-19 Research Collection, and was released in the PhenX Toolkit. Long COVID continues to have an impact on human health. Long COVID is a chronic condition that occurs after SARS-CoV-2 infection and is present for at least 3 months, encompassing a variety of symptoms or conditions that may improve, worsen, or be ongoing. Not surprisingly, submissions to the COVID-19 library began to address Long COVID symptoms. After discussions with its Steering Committee, the PhenX team established a collection of Long COVID measurement protocols. Also, there was significant interest in assessing the amount of overlap among all instruments submitted to the COVID-19 library. The intent was to develop a tool that could identify potential for cross-study analyses. The COVID-19 Variable Compare Tool (VCT) integrates all COVID-19 Research Collection protocols and a prioritized subset of instruments from the COVID-19 library. The Long COVID Specialty Collection and the VCT support investigators' needs to combine and analyze data related to COVID-19 prospectively and retrospectively by identifying compatibility with other studies. © 2026 RTI International. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Exploring Long COVID through PhenX Toolkit Specialty Collections and the Variable Compare Tool.
Krzyzanowski et al. (Wed,) studied this question.