Table 1

Observed cigarette butt discarding behaviour by a single observer on a continuous circuit of downtown streets in central Wellington, New Zealand during October and November 2011

Variables considered	Did not litter (%)	Littered (%)	95% CI	RR	95% CI of RR	p Value
All (n=219)	23.3	76.7	70.8 to 82.0	–	–	–
Smoker demographics (estimated)
Aged ≥50 years (n=39)	17.9	82.1	67.0 to 91.3	1.09	0.92 to 1.29	0.398
Aged <50 years (n=180)	24.4	75.6	68.8 to 81.3	Reference
Male (n=159)	23.3	76.7	69.6 to 82.7	1.00	0.85 to 1.18	0.981
Female (n=60)	23.3	76.7	64.5 to 85.7	Reference
Smoking as part of a group
Single smoker (n=132)	22.7	77.3	69.4 to 83.6	1.02	0.80 to 1.29	0.871
Two people (n=62)	24.2	75.8	63.8 to 84.9	1.00	0.77 to 1.30	1.000
Three or more (n=25)	24.0	76.0	56.3 to 88.8	Reference
How butt was extinguished
Not extinguished (n=161)	5.6	94.4	89.6 to 97.2	20.77	5.36 to 80.48	<0.001
Hand (n=44)	95.5	4.5	0.4 to 16.0	Reference
Foot (n=14)	0.0	100.0	–	–	–	–
Presence of macro litter^*
Yes (n=15)	26.7	73.3	47.6 to 89.5	0.98	0.71 to 1.35	0.883
No (n=162)	25.3	74.7	67.5 to 80.8	Reference
Type of cigarette^* ^†
Roll your own (n=28)	3.6	96.4	80.8 to 100.0	1.11	1.00 to 1.23	0.164
Manufactured (n=108)	13.0	87.0	79.3 to 92.2	Reference
Time of discarding event
Evening (n=106)	14.2	85.8	77.8 to 91.4	1.26	1.09 to 1.46	0.002
Lunchtime (n=113)	31.9	68.1	59.1 to 76.0	Reference
Day of discarding event
Saturday (n=99)	17.2	82.8	74.1 to 89.1	1.16	1.00 to 1.34	0.053
Friday (n=120)	28.3	71.7	63.0 to 79.0	Reference
Location
Courtenay Place (n=109)	19.3	80.7	72.3 to 87.1	1.11	0.96 to 1.29	0.166
Manners Street (n=110)	27.3	72.7	63.7 to 80.2	Reference

↵* Indicates incomplete data collection as this variable was only added into the data collection process after an initial period of data collection.
↵† This could not be ascertained for butts discarded down drains and for some of the butts placed in rubbish bins.