Box 1.

PHQ-4

Over the last two weeks, how often have you been bothered by the following problems?	Not at all	Several days	More than half of the days	Nearly every day
Feeling nervous, anxious or on edgea	0	1	2	3
Not being able to stop or control worryinga	0	1	2	3
Feeling down, depressed or hopelessb	0	1	2	3
Little interest or pleasure in doing thingsb	0	1	2	3

^aItem measures anxiety symptoms and originates from the GAD-2.

^bItem measures depression symptoms and originates from the PHQ-2; interpretation of total score: 0–2 = no complaints; 3–5 = mild complaints; 6–8 = moderate complaints; 9–12 = severe complaints.¹⁵