Construct: Psychological distress among students is a growing concern in medical education, even more so with the advent of COVID-19 pandemic. Anxiety is among students' mental health issues. High and persistent anxiety has many negative impacts on students' academic and personal life. Early detection is essential for timely intervention. Background: Currently, medical student anxiety is assessed using tools primarily designed for psychiatric purposes. Despite their excellent validity evidence, these tools contain sensitive items and do not explore stressors related to clinical activities. There is a need for contextualized tools to better identify anxiety-provoking factors specific to the medical education environment. Approach: We previously developed the Crisis Experience Rating Scale (CERS-7), a short screening tool to identify early on anxious students participating in clinical activities during the first wave of the COVID-19 pandemic. The present study sought to produce further validity evidence for the CERS-7. Medical students in their clinical years at two Swiss and one French medical school, all involved in COVID-19 clinical activity during the second wave of the pandemic, completed the CERS-7 and the State Anxiety Inventory (STAI-A), the best known and widely used tool to measure for general anxiety. We evaluated internal structure using confirmatory factor analysis (CFA) and relation to other variables using linear regression (LR) and receiver operating characteristic (ROC) curves with thresholds defined using the Youden index. Findings: There were 372 participants. CFA confirmed the two-factor structure of the CERS-7 scale from first-wave dataset. The CERS-7 total scale and subscales demonstrated validity evidence in relationship to the STAI-A scores and categories. A CERS-7 total scale score < 27.5 identified 93% of severely anxious students. Conclusion: The CERS-7 produces reliable scores to use for monitoring anxiety status when assigning students to clinical settings as well as for improving training conditions during clinical crisis.