Table 1

Enrolment and quitting by deprivation and ethnicity

	Calculations (letters refer to rows)	Least deprived quintile	Most deprived quintile	p Value	Lowest Māori quintile	Highest Māori quintile	p Value
Enrolment
(a) No in Christchurch 2001		73 020	42 750		49 293	61 605
(b) No enrolled in PEGS		1425	2203		1165	2972
% Of population enrolled	(b/a)×100	2.0	5.2	<0.001	2.4	4.8	<0.001
% Of enrolees from quintile		12.6	19.5	<0.001	10.3	26.2	<0.001
(c) No of smokers 1996		6744	10 767		5373	13 740
(d) No of smokers 2006		6189	10 554		4887	13 962
(e) Change in smokers 96–2006	c−d	−555	−213		−486	+222
(f) Imputed smokers 2001	c+(e/2)	6466.5	10 660.5		5130	13 851
% Of quintile population smoking 2001	(f/a)×100	8.9	24.9	<0.001	10.4	22.5	<0.001
% Of 2001 smokers enrolled	(b/f)×100	22.0	20.7	0.033	22.7	21.5	0.063
Follow-up at 6 months
(g) No of enrolees followed up		995	1502		807	2020
% Of enrolees followed up	(g/b)×100	69.8	68.2		69.3	68.0
(h) No of enrolees who quit		359	385		294	532
% Who quit of those followed up	(h/g)×100	36.1	25.6	<0.001	36.4	26.3	<0.001
% Who quit of those enrolled	(h/b)×100	25.2	17.5	<0.001	25.2	17.9	<0.001
Adjustments to quit rate
(i) No who quit if 37.5% relapse	h×625	224.4	240.6		183.8	332.5
(j) No likely to quit without PEGS	i×025	5.6	6.0		4.6	8.3
(k) No who quit because of PEGS	i−j	218.8	234.6		179.2	324.2
PEGS impact on Christchurch population
(l) Estimated No smoking 2006 without Pegasus	d+k	6407.8	10 788.6		5066.2	14 286.2
(m) No in Christchurch 2006		74 298	44 541		51 642	63 330
% Smoking 2006	(d/m)×100	8.3	23.7		9.5	22.0
Estimated % smoking 2006 without PEGS	(l/m)×100	8.6	24.2		9.8	22.6