Table 3. Hazard ratios for suicide deaths at 30 days and 365 days after completion of the PHQ9 by age group.

Question 9 of the PHQ9 asks about thoughts of being better off dead or of hurting oneself in some way over the last two weeks. Response options include “not at all” (Q9=0), “several days” (Q9=1), “more than half the days” (Q9=2), or “nearly every day” (Q9=3).^*

Age Group	PHQ9 item 9 score	30 Days		365 Days
		Hazard Ratio	95% CI	Hazard Ratio	95% CI
Ages 18–29	Q9=0	[reference]		[reference]
	Q9=1	3.94	1.81–8.56	2.58	1.35–4.91
	Q9=2	2.27	1.10–4.69	1.04	0.44–2.46
	Q9=3	3.29	1.62–6.68	1.74	0.85–3.57
	Q9>0	3.46	2.05–5.87	1.98	1.22–3.22
Ages 30–44	Q9=0	[reference]		[reference]
	Q9=1	2.30	1.27–4.15	1.50	0.76–2.98
	Q9=2	3.14	1.25–7.89	1.45	0.58–3.62
	Q9=3	5.69	2.62–12.34	3.00	1.29–7.01
	Q9>0	2.93	1.71–5.00	1.67	0.93–2.99
Ages 45–64	Q9=0	[reference]		[reference]
	Q9=1	2.87	1.66–4.98	1.88	1.17–3.01
	Q9=2	3.43	1.50–7.85	1.58	0.79–3.15
	Q9=3	5.63	2.69–11.81	2.97	1.39–6.36
	Q9>0	3.36	1.95–5.77	1.92	1.22–3.02
Ages 65+	Q9=0	[reference]		[reference]
	Q9=1	4.22	2.05–8.65	2.76	1.36–5.60
	Q9=2	12.95	4.57–36.68	5.96	1.54–23.04
	Q9=3	10.81	3.63–32.17	5.70	1.65–19.70
	Q9>0	6.97	3.04–15.96	3.98	1.56–10.12

p=0.346

^*Models adjusted for gender, healthcare system, patient mental health treatment status, visit type, Charlson score and race/ethnicity.