Patients' perspectives on smoking and inflammatory bowel disease: An online survey in collaboration with European Federation of Crohn's and Ulcerative Colitis Associations

Table 2 Smoking habits and use of alternative smoking products based on type of diagnosis

Questionnaire items	Crohn’s disease	Ulcerative colitis	P value1
Smoking habits and use of an alternative smoking product
Current cigarettes smoker
Yes	268/425 (63.1)	187/346 (54.1)	0.012
No	157/425 (36.9)	159/346 (45.9)
Duration of cigarette smoking (yr)
< 1	22/410 (5.4)	26/317 (8.2)	0.13
1-5	46/410 (11.2)	47/317 (14.8)
6-10	69/410 (16.8)	56/317 (17.7)
> 10	273/410 (66.6)	188/317 (59.3)
Extent of cigarette smoking (cigarettes per day)
< 1	12/425 (2.8)	22/341 (6.5)	< 0.001
1-5	51/425 (12.0)	67/341 (19.6)
6-10	120/425 (28.3)	106/341 (31.1)
11-20	179/425 (42.1)	113/341 (33.1)
> 20	63/425 (14.8)	33/341 (9.7)
Current use of an alternative smoking product
Yes	343/427 (80.3)	282/355 (79.4)	0.79
No	84/427 (19.7)	73/355 (20.6)
Type of smoking/nicotine product ever used
Cigarettes	409/427 (95.8)	330/355 (93.0)	0.11
E-cigarettes	84/427 (19.7)	71/355 (20.0)	0.93
Heat not burn tobacco product	19/427 (4.5)	25/355 (7.0)	0.12
Nicotine gum	37/427 (8.7)	36/355 (10.1)	0.54
Nicotine patches	21/427 (4.9)	23/355 (6.5)	0.35
Chewing tobacco/snus/snuff	10/427 (2.3)	15/355 (4.2)	0.16
Cigars	44/427 (10.3)	31/355 (8.7)	0.47
Pipes	13/427 (3.0)	8/355 (2.3)	0.66
Marijuana	81/427 (19.0)	56/355 (15.8)	0.26
Any other combustion/smoking product	11/427 (2.6)	5/355 (1.4)	0.31
None of the above	2/427 (0.5)	7/355 (2.0)	0.09
Ever stopped cigarette smoking and restarted
Yes	264/426 (62.0)	253/346 (73.1)	0.001
No	162/426 (38.0)	93/346 (26.9)
Ever user of an alternative smoking product
Yes	215/427 (50.4)	196/354 (55.4)	0.17
No	212/427 (49.6)	158/354 (44.6)
Current use of an alternative smoking product
Yes	84/427 (19.7)	73/355 (20.6)	0.79
No	343/427 (80.3)	282/355 (79.4)
Duration of use of alternative smoking products
< 1	44/76 (55.3)	46/81 (56.7)	0.33
1-5	23/76 (30.3)	16/81 (19.8)
6-10	10/76 (13.1)	16/81 (19.8)
> 10	1/76 (1.3)	3/81 (3.7)
Started cigarette smoking
Before IBD diagnosis	392/426 (92.0)	290/343 (84.6)	0.001
After IBD diagnosis	34/426 (8.0)	53/343 (15.4)
Stopped cigarette smoking
Before IBD diagnosis	85/250 (34.0)	146/247 (59.1)	< 0.001
After IBD diagnosis	165/250 (66.0)	101/247 (40.9)
Restarted cigarette smoking
Before IBD diagnosis	89/260 (34.2)	66/243 (27.2)	0.10
After IBD diagnosis	171/260 (65.8)	177/243 (72.8)
Started using an alternative smoking product
Before IBD diagnosis	85/210 (40.5)	85/185 (46.0)	0.31
After IBD diagnosis	125/210 (59.5)	100/185 (54.0)
Switched from cigarette smoking to using an alternative smoking product
Before IBD diagnosis	77/207 (37.2)	81/184 (44.0)	0.18
After IBD diagnosis	130/207 (62.8)	103/184 (56.0)

The survey had a hierarchical structure, meaning that only patients who answered to certain items could answer to other following questions. For this reason, the denominator for several questions is different. In some cases, the patient did not answer and this can result in a missing value. We have transparently declared in our tables the denominator we have used to calculate the proportion of patients giving certain answers.

¹Fisher’s exact test. IBD: Inflammatory bowel diseases.