Table 3.

Odds ratios of linear and quadratic models for ever drunk alcohol and ever cannabis use between 1998–2015 for England, Scotland and Wales

		Ever drunk alcohol				Ever used cannabis
		Linear	P value	Quadratic	P value	Linear	P value	Quadratic	P value
Whole sample (n=239 190; 239 457)	Year	0.91 (0.90 to 0.91)	<0.001	1.10 (1.08 to 1.12)	<0.001	0.92 (0.92 to 0.92)	<0.001	1.08 (1.07 to 1.10)	<0.001
	Year2	–	–	0.99 (0.99 to 0.99)	<0.001	–	–	0.99 (0.99 to 0.99)	<0.001
	Level	0.90 (0.85 to 0.95)	<0.001	0.85 (0.81 to 0.90)	<0.001	0.98 (0.90 to 1.07)	0.661	1.01 (0.93 to 1.10)	0.761
	Post-slope	0.96 (0.94 to 0.97)	<0.001	1.17 (1.14 to 1.19)	<0.001	1.00 (0.98 to 1.03)	0.667	1.21 (1.18 to 1.25)	<0.001
Male only subgroup (n=119 989; 120 025)	Year	0.91 (0.90 to 0.91)	<0.001	1.06 (1.03 to 1.09)	<0.001	0.93 (0.92 to 0.93)	<0.001	1.06 (1.04 to 1.09)	<0.001
	Year2	–	–	0.99 (0.99 to 0.99)	<0.001	–	–	0.99 (0.99 to 0.99)	<0.001
	Level	0.89 (0.82 to 0.96)	0.004	0.85 (0.79 to 0.92)	<0.001	0.92 (0.82 to 1.04)	0.185	0.94 (0.84 to 1.06)	0.337
	Post–slope	0.96 (0.94 to 0.98)	<0.001	1.12 (1.09 to 1.16)	<0.001	1.02 (0.99 to 1.05)	0.175	1.20 (1.15 to 1.24)	<0.001
Female only subgroup (n=119 201; 119 432)	Year	0.90 (0.90 to 0.91)	<0.001	1.15 (1.12 to 1.18)	<0.001	0.92 (0.91 to 0.92)	<0.001	1.11 (1.08 to 1.14)	<0.001
	Year2	–	–	0.99 (0.98 to 0.99)	<0.001	–	–	0.99 (0.99 to 0.99)	<0.001
	Level	0.91 (0.84 to 0.98)	0.016	0.85 (0.79 to 0.92)	<0.001	1.06 (0.93 to 1.20)	0.396	1.11 (0.98 to 1.26)	0.110
	Post–slope	0.96 (0.94 to 0.97)	<0.001	1.22 (1.18 to 1.26)	<0.001	0.99 (0.95 to 1.02)	0.359	1.23 (1.17 to 1.28)	<0.001
13 year olds only (n=124 842; 123 608)	Year	0.90 (0.90 to 0.90)	<0.001	1.11 (1.08 to 1.13)	<0.001	0.90 (0.89 to 0.90)	<0.001	1.16 (1.12 to 1.21)	<0.001
	Year2	–	–	0.99 (0.99 to 0.99)	<0.001	–	–	0.98 (0.98 to 0.99)	<0.001
	Level	0.88 (0.82 to 0.95)	0.001	0.84 (0.78 to 0.91)	<0.001	1.07 (0.89 to 1.28)	0.480	1.14 (0.95 to 1.37)	0.165
	Post–slope	0.95 (0.93 to 0.97)	<0.001	1.17 (1.14 to 1.21)	<0.001	0.99 (0.95 to 1.04)	0.746	1.34 (1.26 to 1.42)	<0.001
15 year olds only (n=114 348; 115 849)	Year	0.92 (0.91 to 0.92)	<0.001	1.08 (1.05 to 1.11)	<0.001	0.93 (0.92 to 0.93)	<0.001	1.06 (1.04 to 1.08)	<0.001
	Year2	–	–	0.99 (0.99 to 0.99)	<0.001	–	–	0.99 (0.99 to 0.99)	<0.001
	Level	0.92 (0.84 to 1.00)	0.049	0.87 (0.80 to 0.95)	0.002	0.96 (0.87 to 1.06)	0.432	0.99 (0.90 to 1.09)	0.776
	Post–slope	0.96 (0.94 to 0.98)	<0.001	1.13 (1.09 to 1.17)	<0.001	1.01 (0.98 to 1.03)	0.645	1.17 (1.13 to 1.20)	<0.001