Table 3. Risk of NPAEs associated with the use of montelukast in the previous 7 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	12 673/161 386	(7.85)	48 882/645 544	(0.08)	1.07	(1.04 to 1.09)	1.23	(1.20 to 1.27)
Age group (years)									0.0063
0–2	864/5332	(16.20)	3518/21 328	(16.49)	0.97	(0.88 to 1.07)	1.10	(0.99 to 1.22)
3–5	2530/21 312	(11.87)	10 199/85 248	(11.96)	0.99	(0.93 to 1.05)	1.14	(1.08 to 1.22)
6–9	4648/49 079	(9.47)	17 996/196 316	(9.17)	1.06	(1.02 to 1.11)	1.23	(1.18 to 1.29)
10–12	1413/21 026	(6.72)	5450/84 104	(6.48)	1.07	(0.99 to 1.15)	1.36	(1.25 to 1.47)
13–19	3218/64 637	(4.98)	11 719/258 548	(4.53)	1.16	(1.11 to 1.22)	1.44	(1.37 to 1.52)
Gender									0.1195
Male	8137/94 049	(8.65)	31 812/376 196	(8.46)	1.04	(1.01 to 1.08)	1.26	(1.22 to 1.30)
Female	4536/67 337	(6.74)	17 070/269 348	(6.34)	1.11	(1.06 to 1.16)	1.35	(1.29 to 1.41)
Season									<0.0001
Spring	2973/35 912	(8.28)	10 680/143 648	(7.43)	1.21	(1.15 to 1.28)	1.40	(1.32 to 1.48)
Summer	2344/43 872	(5.34)	10 841/175 488	(6.18)	0.78	(0.73 to 0.82)	0.97	(0.91 to 1.03)
Autumn	4259/47 157	(9.03)	14 048/188 628	(7.45)	1.40	(1.34 to 1.47)	1.71	(1.63 to 1.79)
Winter	3097/34 445	(8.99)	13 313/137 780	(9.66)	0.88	(0.84 to 0.93)	1.08	(1.02 to 1.14)

^*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