Table 2.

Hazard ratios (HRs) for suicide with 95% confidence intervals (CIs). Model 1: age-adjusted model. Model 2: additive model including information on previous use of antidepressants. Model 3: interaction model, estimating the effect of prostate cancer on suicide risk depending on the status of previous depression.

				Model 1: Age-adjusted model		Model 2: Previous use of antidepressants (additive model)		Model 3: Interaction model
	n	Events	PYRS	HR	95% CI	HR	95% CI	HR	95% CI
Cancer-free men	357,384	1239	3,084,849	1.00	Reference	1.00	Reference
Prostate cancer	37,527	108	237,638	1.05	(0.85–1.26)	1.02	(0.84–1.25)
Age at diagnosis, per year				1.05	(1.04–1.06)	1.05	(1.04–1.06)
No previous use of antidepressants	358,696	1134	3,069,137			1.00	Reference
Previous use of antidepressants	36,215	213	253,351			2.24	(1.93–2.59)
Cancer-free men with previous depression	32,402	187	231,889					1.00	Reference	p = 0.1*
Prostate cancer patients with previous depression	3813	26	21,462					1.39	(0.92–2.10)
Cancer-free men without previous depression	324,982	1052	2,852,960					0.44	(0.34–0.57)
Prostate cancer patients without previous depression	33,714	82	216,177					0.47	(0.40–0.54)

^*p-value of analysis of variance between the additive model (Model 2) and the interaction model (Model 3).