The Coronavirus Anxiety Scale (CAS) is a five-item self-report screener for dysfunctional anxiety specifically triggered by coronavirus-related information and experiences.

Study	Population / setting	Key points
Lee 2020, Death Studies	Adults in the United States reporting anxiety about the coronavirus (approximately 775 participants)	Twenty candidate anxiety items were reduced to five physiological items (dizziness, sleep disturbance, tonic immobility, appetite loss and abdominal distress). Total scores from 0 to 20 were strongly related to functional impairment and maladaptive coping behaviours.
Lee et al. 2020, Psychiatry Res	Online sample of 398 US adults recruited via Amazon Mechanical Turk	Confirmed a single-factor structure. A cut-off of ≥9 best identified people whose coronavirus-related anxiety was causing functional impairment, with good specificity and a low false-positive rate.
Cross-cultural validations	General population, student, healthcare and international samples across multiple languages	Arabic, Italian, Chinese and multi-country studies show high internal consistency and a stable one-factor structure. Most use ≥9 to flag clinically significant anxiety, although some have explored lower thresholds or a 1-week reference period.

Higher CAS scores correlate with depression, generalised anxiety, suicidal ideation, alcohol or drug coping and reduced functioning, so elevated scores should prompt a broader mental health and risk assessment rather than being treated as a diagnosis on their own.

The scale was derived and first validated in adults. Most evidence is from adult community, student and healthcare samples. Use in children or younger adolescents is less well characterised.

This calculator implements the original English-language version that anchors responses to the previous 2 weeks and uses a cut-off of ≥9 when flagging probable dysfunctional coronavirus-related anxiety.