Table 1 Demographic variables at the time of diagnosis in the Crohn's disease patients included in the study.
| Sex (M/F) | 121/79 |
| Median age at diagnosis (y) | 11.2 (IQR 8.6 to 13.0) |
| Current smoker | 3 (2%) |
| Family history | 68 (34%) |
| White (%) | 195 (97%) |
| Location according to the Vienna classification28 | |
| Terminal ileum (L1) | 9 (4.6%) |
| Colon (L2) | 48 (24.4%) |
| Ileocolon (L3) | 38 (19.2%) |
| Upper gastrointestinal (L4) | 93 (47.2%) |
| None* | 9 (4.6%) |
| Behaviour according to the Vienna classification28 | |
| Inflammatory (B1) | 163 (82.7%) |
| Stricturing (B2) | 7 (3.6%) |
| Penetrating (B3) | 27 (13.7%) |
| Disease location† | |
| Oral | 27/182 (14.8%) |
| Oesophageal | 7/170 (4.1%) |
| Gastric antrum | 49/168 (29.2%) |
| Gastric body | 32/167 (19.1%) |
| Duodenal | 26/167 (15.6%) |
| Jejunal | 29/165 (17.6%) |
| Ileal | 111/173 (64.2%) |
| Caecal | 108/142 (76.0%) |
| Ascending | 110/146 (75.3%) |
| Transverse | 119/156 (76.3%) |
| Descending | 125/167 (77.1%) |
| Sigmoid | 137/174 (78.7%) |
| Rectal | 139/182 (76.4%) |
| Perianal‡ | 80/190 (42.1%) |
| Perianal§ | 20/190 (10.5%) |
| Anthropometry¶ | |
| Weight <9th centile | 71/185 (38.4%) |
| Weight <25th centile | 104/185 (56.2%) |
| Height <9th centile | 46/178 (25.8%) |
| Height <25th centile | 83/178 (46.6%) |
| BMI <9th centile | 66/178 (37.1%) |
| BMI <25th centile | 92/178 (51.7%) |
| Mean weight z score (SD) | −0.68 (1.55) |
| Mean height z score (SD) | −0.48 (2.01) |
| Mean BMI z score (SD) | 0.66 (1.60) |
| Associated diseases | |
| Asthma | 58/198 (29.3%) |
| Eczema | 68/198 (34.3%) |
| Hayfever | 41/198 (20.7%) |
| All three diseases | 15/198 (7.9%) |
The phenotypic data at diagnosis are based on 197 Crohn's disease patients unless otherwise stated.
*These were patients who fulfilled the diagnostic criteria for Crohn's disease but whose disease location does not allow the use of the Vienna classification; all had perianal or oral Crohn's disease or both without evidence of disease elsewhere in the gastrointestinal tract.
†The presence or absence of evidence for Crohn's disease activity in each location was based on evidence from endoscopy, biopsy, or barium follow through and was independent of disease activity elsewhere in the gastrointestinal tract.
‡Perianal disease was defined by the presence of fissures, perianal ulcers, abscesses, or fistulae but not by the presence of skin tags alone.
§Perianal disease was defined by the presence perianal ulcers, abscesses, or fistulae but not by the presence of skin tags or fissures.
¶Based on centile plotted on UK Growth Chart (© Child Growth Foundation, 1996).
BMI, body mass index; IQR, interquartile range; y, years.