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

Table 1 Baseline characteristics reported by the participants (n = 1050)

Questionnaire items	mean ± SD; median (IQR) or n(%)
Demographic characteristics
Age (n = 796)	41.9 ± 12.4; 40.0 (32.0–51.0)
Gender
Female	522/798 (65.4)
Male	276/798 (34.6)
Language
Italian	213 (20.3)
Finnish	146 (13.9)
Portuguese	146 (13.9)
Slovenian	128 (12.2)
Spanish	120 (11.4)
Greek	102 (9.7)
English	83 (7.9)
German	57 (5.4)
French	55 (5.3)
IBD characteristics and treatments
Diagnosis
Crohn’s disease	427/798 (53.5)
Ulcerative colitis	355/798 (44.5)
No gastrointestinal condition	5/798 (0.6)
Other gastrointestinal condition	11/798 (1.4)
Crohn’s disease duration (yr)	13.6 ± 10.6; 11 (5–20)
Ulcerative colitis duration (yr)	7.52 ± 9.12; 4 (1–8)
Self-perceived disease activity
Inactive	155/770 (20.1)
Mildly active	261/770 (33.9)
Moderately active	251/770 (32.6)
Severely active	76/770 (9.9)
Not sure	27/770 (3.5)
Self-perceived disease severity since diagnosis
Mild	173/768 (22.5)
Moderate	360/768 (46.9)
Severe	201/768 (26.2)
Not sure	34/768 (4.4)
Intestinal surgery	230/798 (28.8)
Type of surgery
Partial colectomy	41/798 (5.1)
Full colectomy	29/798 (3.6)
Small-bowel resection	48/798 (6.0)
Ileocaecal resection	94/798 (11.8)
Other	79/798 (9.9)
Current IBD-related medications
Antibiotics	41/798 (5.1)
Oral aminosalicylate	318/798 (39.8)
Topical aminosalicylate	91/798 (11.4)
Topical steroid	47/798 (5.9)
Systemic steroid	78/798 (9.8)
Budesonide	28/798 (3.5)
Immunomodulator	213/798 (26.7)
Anti-TNF	225/798 (28.2)
Combination of anti-TNF and immunomodulator	69/798 (8.6)
Anti-integrin	51/798 (6.4)
Tofacitinib	6/798 (0.8)
Ustekinumab	28/798 (3.5)
None	76/798 (9.5)
Other	135/798 (16.9)
Duration of current medical therapy (yr)
< 1	240/765 (31.4)
1-5	262/765 (34.2)
> 5	263/765 (34.4)
Concomitant non-IBD drug treatment
Yes	282/767 (63.2)
No	485/767 (36.8)

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. IBD: Inflammatory bowel diseases; IQR: Interquartile ranges.

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.

Table 3 Perceived effect of smoking on inflammatory bowel diseases based on type of diagnosis

Questionnaire items	Crohn’s disease	Ulcerative colitis	P value1
Perceived impact of cigarette smoking on disease activity
Significantly worsened	12/279 (4.3)	2/191 (1.0)	< 0.001
Moderately worsened	209/279 (74.9)	63/191 (33.0)
No impact	27/279 (9.7)	12/191 (6.3)
Moderately improved	25/279 (9.0)	58/191 (30.4)
Significantly improved	6/279 (2.2)	56/191 (29.3)
Perceived impact of using alternative smoking products on disease activity
Significantly worsened	4/211 (1.9)	12/187 (6.4)	0.004
Moderately worsened	31/211 (14.7)	14/187 (7.5)
No impact	146/211 (69.2)	118/187 (63.1)
Moderately improved	23/211 (10.9)	28/187 (15.0)
Significantly improved	7/211 (3.3)	15/187 (8.0)

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.

Table 4 Extent of discussing with own physician the effect of smoking on inflammatory bowel diseases based on type of diagnosis

Questionnaire items	Crohn’s disease	Ulcerative colitis	P value1
Cigarette smoking
Not discussed	89/412 (21.6)	143/321 (44.6)	< 0.001
Detrimental	286/412 (69.4)	47/321 (14.6)
Possibly beneficial	37/412 (9.0)	131/321 (40.8)
Use of alternative smoking products
Not discussed	43/83 (51.8)	45/72 (62.5)	< 0.001
Detrimental	31/83 (37.4)	8/72 (11.1)
Possibly beneficial	9/83 (10.8)	19/72 (26.4)

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.