Table 4

Associations of social media use with current e-cigarette and cigarette dual use from generalised estimating equation model

Weekday social media use (hours/day)	AOR	P value	Lower CI	Upper CI
None or not a member	Ref.	Ref.	Ref.	Ref.
<1 hour	2.33	0.095	0.86	6.27
1–3 hours	3.28	0.017	1.24	8.70
4–6 hours	4.26	0.005	1.55	11.72
≥7 hours	4.96	0.003	1.71	14.34
Year (2015/2016)	Ref.	Ref.	Ref.	Ref.
2016/2017	0.19	<0.001	0.11	0.31
2017/2018	0.26	<0.001	0.17	0.40
2018/2019	0.42	<0.001	0.28	0.63
2019/2020	0.30	<0.001	0.18	0.51
2020/2021	0.32	<0.001	0.17	0.59
Sex (male vs female)	2.16	<0.001	1.54	3.02
Age (continuous)	1.19	<0.001	1.13	1.25
England	Ref.	Ref.	Ref.	Ref.
Wales	0.96	0.903	0.52	1.77
Scotland	0.73	0.255	0.43	1.25
Northern Ireland	0.95	0.854	0.53	1.68
White ethnicity	Ref.	Ref.	Ref.	Ref.
Non-White ethnicity	0.72	0.282	0.39	1.32
Rural area vs urban	1.21	0.304	0.84	1.75
Household income group lowest	Ref.	Ref.	Ref.	Ref.
Household income group middle	0.89	0.526	0.63	1.27
Household income group highest	0.68	0.060	0.46	1.02
Parental smoking yes vs no	2.10	0.000	1.47	3.02
Parental e-cigarette use yes vs no	1.94	<0.001	1.29	2.91