Table 4.

Multivariable Poisson Regression Analysis on Suicide Attempt Rates

	Incidence Rate Ratio	95% Confidence Interval	p-value
Age <25 years
Month
-1	1.00
+1	1.47	0.80–2.69	0.212
+2	0.70	0.30–1.61	0.407
+3	1.12	0.51–2.43	0.773
+4–6	0.86	0.44–1.67	0.661
Overall effect of month			0.3055 (df = 4)
Age 25–40 years
Month
-1	1.00
+1	0.77	0.46–1.26	0.306
+2	0.41	0.20–0.84	0.015
+3	0.36	0.16–0.83	0.016
+4–6	0.58	0.35–0.96	0.034
Overall effect of month			0.0239 (df = 4)
Age 40–60 years
Month
-1	1.00
+1	0.44	0.24–0.80	0.008
+2	0.35	0.16–0.75	0.008
+3	0.49	0.24–1.03	0.063
+4–6	0.26	0.14–0.51	0.001
Overall effect of month			0.0003 (df = 4)
Age >60 years
Month
-1	1.00
+1	0.56	0.25–1.27	0.170
+2	0.19	0.04–0.86	0.031
+3	0.26	0.06–1.15	0.077
+4–6	0.05	0.007–0.41	0.005
Overall effect of month			0.0082 (df = 4)
Ix {month x age-categorized}			0.1088 (df = 12)
Ix {month x age-continous}			0.0005 (df = 4)

Comparing the months after the start with antidepressants (during episodes of antidepressant use) with the month before the start with antidepressants, by age category.