Table 1. Socio-demographic features of participants by smoking status.

	Socio-demographic variables	Whole sample n	Smoker	Non-smoker	p-value (Chi-square)
n		9,657	2,019	7,628
Age band	16 to 24	865	11.9%	8.2%
	25 to 34	1,306	18.8%	12.2%
	35 to 44	1,730	20.5%	17.3%
	45 to 54	1,731	18.5%	17.8%	p<0.001
	55 to 64	1,687	17.3%	17.5%
	65 to 74	1,277	8.6%	14.5%
	75 and over	1,051	4.4%	12.6%
Gender	Male	4,304	45.9%	44.3%
	Female	4,251	54.1%	55.7%
Ethnicity	White British/other White	8,746	94.0%	89.9%
	Mixed race	64	0.8%	0.6%	p = 0.20
	Asian-Indian	265	0.9%	3.2%
	Asian-Pakistani & Bangladeshi	165	0.8%	2.0%	p<0.001
	Asian-Other	67	0.3%	0.8%
	Black Caribbean	85	1.1%	0.8%
	Black African	89	0.4%	1.1%
	Other Black	4	0.1%	0.0%
	Other ethnic group	149	1.4%	1.6%
Deprivation (IMD)	1 most deprived	1,497	25.0%	13.0%
	2	1,782	22.7%	17.3%
	3	2,168	22.8%	22.4%
	4	2,062	16.8%	22.6%	p<0.001
	5 least deprived	2,138	12.7%	24.7%
Region	North East	990	11.5%	9.9%
	North West	969	11.9%	9.5%
	Yorkshire & the Humber	1,020	12.5%	10.1%
	East Midlands	1,130	11.3%	11.8%	p<0.001
	West Midlands	873	8.2%	9.3%
	East of England	1,033	10.6%	10.7%
	London	761	7.8%	7.9%
	South East Coast	896	8.9%	9.4%
	South Central	966	6.9%	10.8%
	South West	1,009	10.4%	10.5%