Table 4. Risk of NPAEs associated with the use of montelukast in the previous 14 days, stratified analysis according to age group, gender and season.

Variables	Exposed in hazard period		Exposed in control period		Crude		Adjusted		P value for interaction*
	N/N	(%)	N/N	(%)	OR (95% CI)†		OR (95% CI)‡
Total	17,080/161 386	(10.58)	63,578/645 544	(9.985)	1.13	(1.10 to 1.15)	1.28	(1.25 to 1.31)
Age group (years)									0.1821
0–2	1173/5332	(22.00)	4586/21 328	(21.50)	1.04	(0.96 to 1.13)	1.16	(1.07 to 1.27)
3–5	3433/21 312	(16.11)	13 165/85 248	(15.44)	1.08	(1.03 to 1.14)	1.23	(1.17 to 1.30)
6–9	6293/49 079	(12.82)	23 526/196 316	(11.98)	1.12	(1.08 to 1.16)	1.29	(1.24 to 1.34)
10–12	1896/21 026	(9.02)	7103/84 104	(8.45)	1.11	(1.04 to 1.19)	1.37	(1.28 to 1.47)
13–19	4285/64 637	(6.63)	15 198/258 548	(5.88)	1.19	(1.15 to 1.24)	1.43	(1.37 to 1.50)
Gender									0.8972
Male	10 965/94 049	(11.66)	41 073/376 196	(10.92)	1.12	(1.09 to 1.15)	1.32	(1.28 to 1.36)
Female	6115/67 337	(9.08)	22 205/269 348	(8.36)	1.14	(1.10 to 1.18)	1.36	(1.31 to 1.41)
Season									<0.0001
Spring	3989/35 912	(11.11)	13 309/143 648	(9.27)	1.35	(1.29 to 1.42)	1.53	(1.46 to 1.60)
Summer	3231/43 872	(7.36)	15 729/175 488	(8.96)	0.73	(0.69 to 0.76)	0.89	(0.85 to 0.93)
Autumn	5679/47 157	(12.04)	16 089/188 628	(8.53)	1.80	(1.69 to 1.83)	2.08	(1.99 to 2.16)
Winter	4181/34 445	(12.14)	18 451/137 780	(13.39)	0.85	(0.81 to 0.88)	1.02	(0.97 to 1.06)

^*Joint test for exposure and strata variable interaction, indicating whether montelukast affects NPAEs differently depending on age group, gender, and season.

^†Calculated by conditional logistic regression.

^‡Calculated by conditional logistic regression adjusted for concomitant medication.

NPAEsneuropsychiatric adverse events