TABLE 2.

Risk of neuropsychiatric events in relation to leukotriene receptor antagonist (LTRA) use in patients with asthma or allergic rhinitis

	Total period				Observation period 1				Observation period 2
	Events (n)	Person-years	IRR (95% CI)	p-value	Events (n)	Person-years	IRR (95% CI)	p-value	Events (n)	Person-years	IRR (95% CI)	p-value
Unexposed	21 028	49 546.89	1		5294	12 519.69	1		15 734	37 027.2	1
Exposed	571	1455.98	1.05 (0.96–1.15)	0.266	130	371.49	0.88 (0.73–1.06)	0.185	441	1084.5	1.11 (1.00–1.22)	0.0468
Time since initiation of LTRA (days)
1–3	115	444.70	0.68 (0.57–0.82)	<0.001	28	107.86	0.65 (0.44–0.93)	0.025	87	336.85	0.69 (0.56–0.85)	<0.001
4–7	180	228.38	2.10 (1.80–2.43)	<0.001	31	57.92	1.35 (0.93–1.9)	0.099	149	170.46	2.36 (1.99–2.76)	<0.001
8–14	133	221.99	1.60 (1.34–1.89)	<0.001	27	61.66	1.11 (0.74–1.59)	0.603	106	160.33	1.78 (1.46–2.15)	<0.001
15–30	66	244.77	0.71 (0.55–0.90)	0.007	20	68.13	0.74 (0.46–1.12)	0.183	46	176.64	0.70 (0.51–0.92)	0.015
31–90	51	219.15	0.61 (0.46–0.80)	<0.001	16	53.61	0.74 (0.43–1.18)	0.243	35	165.54	0.57 (0.40–0.78)	<0.001
>90	26	96.99	0.73 (0.47–1.07)	0.130	8	22.30	0.95 (0.42–1.89)	0.903	18	74.69	0.66 (0.39–0.82)	0.094

IRR: incidence rate ratio.