LAUSR

The COVID-19 pandemic and efforts to mitigate the spread and impact of the virus have drastically altered day-to-day operations of research trials. In the United States, widespread “lockdowns” or “stay at home” orders have halted research operations at many institutions. In some cases, institutions have halted inperson visits that are not of medical necessity. This has left many randomized behavioral clinical trials in unprecedented positions. McDermott & Newman (2020) recently discussed maintaining the integrity of trials during this pandemic, providing practical suggestions to minimize the disruption that the current pandemic has on ongoing trials. For example, they suggest adapting study protocols for trials that are already ongoing by prioritizing collection of primary outcomes, exploring alternate measures, and transitioning to mail-in or other remote methods of outcome collection. They also provide guidance on retaining study staff and the recruitment and engagement of study participants remotely. Guidelines from the FDA (2020) have also been released to support investigators running trials at this time, emphasizing participants’ safety. These recommendations suggest examining whether it might be appropriate to delay assessments for ongoing trials or modify intervention delivery modalities. These guidelines recognize that delays in assessments, halting ongoing recruitment, and withdrawing participants from the trial may be necessary depending on the nature of the trial, the intervention, the timing of the disruption, and safety concerns. Investigators are encouraged to consult with institutional review boards and study sponsors to discuss anticipated changes in protocols and document in detail all protocol deviations and missing data information. However, no studies to date have specifically addressed threats to the validity of the data collected during the pandemic, nor how modifications to study protocols to maintain study integrity could pose significant threats to the validity of the data collected from these trials. Randomized behavioral clinical trials will face unique challenges during this time. The COVID-19 pandemic is a textbook example of a “history effect,” which can pose a substantial threat to study validity (in-depth discussions on study validity can be found throughout the literature, e.g., Campbell & Stanley, 1963; Cook & Campbell, 1979). A history effect refers to events that occur in the environment that can change the conditions of a study, affecting its outcome. History effects have the potential to differentially change how individuals and study groups respond to treatments or interventions. How this history effect impacts a particular study will depend on the timing of the pandemic onset within a specific study timeline, the overall length of the study, and the magnitude of the modifications and alterations needed to preserve the study. Indeed, the modifications and alterations implemented to preserve trials during this time may inadvertently compound the history effect by introducing additional threats to data validity, such as maturation (e.g., pediatric participants experiencing significant developmental maturing between a lag in