Table 1

Summary of cohort registered on 1 January 2005 (n=211 016)

Characteristic	Subgroup	N	Per cent
Gender	Men	107 226	50.8
	Women	103 790	49.2
Age	40–64	161 325	76.5
	65–79	49 691	23.6
Smoking†	Never	105 614	50.1
	Ex (amount unknown)	17 418	8.3
	Ex (light)	18 199	8.6
	Ex (heavy)	8840	4.2
	Current (amount unknown)	2294	1.1
	Current (light)	28 483	13.5
	Current (heavy)	14 503	6.9
	Missing	15 665	7.4
BMI	10–20	9589	4.5
	20–25	64 304	30.5
	25–30	61 384	29.1
	30–40	31 573	15.0
	40+	3436	1.6
	Missing	40 730	19.3
Index of Multiple Deprivation	1 (least deprived)	40 830	19.4
	2	49 494	23.5
	3	41 282	19.6
	4	51 123	24.2
	5 (most deprived)	28 287	13.4
Practice borough	Inner London	40 647	19.3
	Outer London	170 639	80.7
Time registered with practice	<10 years	79 797	37.8
	10+ years	131 219	62.2
High exposure to aircraft or rail noise*	No	155 670	73.8
	Aircraft or rail	55 346	26.2

*Lives in postcode within the 50 dB noise contour of Heathrow or City airport, or overland rail.
^†Smoking amount categories were classed as light (1-19 cigarettes/day), heavy (20+ cigarettes/day) or unknown where not recorded.
BMI, body mass index.