Background
Methods
Study population
Age at diagnosis | Brita Group A (5 to 10 years) | Brit Group B (11–16 years) | Itab Group A (5 to 10 years) | Ita Group B (11–16 years) |
---|---|---|---|---|
Patients’ number | 40 | 40 | 40 | 40 |
Distribution by gender | 23 Mc 17 Fd
| 25 M 15 F | 15 M 25 F | 20 M 20 F |
Age at diagnosis | ||||
Mean ± SDe
| 7.65 ± 2.38 | 14.1 ± 1.03 | 7.4 ± 3.1 | 13.4 ± 1.39 |
Median | 8.34 | 14.3 | 7.9 | 13.5 |
Range | 5.1–10.6 | 11.4–16.6 | 5.6–10.8 | 11.2–16.3 |
Distribution by type of IBDf
| 15 CDg
| 19 CD | 16 CD | 22 CD |
4 IBD-Uh CD-like | 5 IBD-U CD-like | 1 IBD-U CD-like | 1 IBD-U CD-like | |
12 UCi
| 7 UC | 15 UC | 15 UC | |
9 IBD-U UC-like | 9 IBD-U UC-like | 8 IBD-U UC-like | 2 IBD-U UC-like | |
Follow-up duration (years) | ||||
Mean ± SD | 3.1 ± 2.3 | 1.92 ± 1.19 | 4.5 ± 3.71 | 2.21 ± 2.4 |
Median | 2.8 | 1.72 | 4.2 | 1.17 |
Range | 0.1–11.14 | 0.3–4.62 | 0.04–11.7 | 0.07–9.5 |
Ethnicity | 36 white British | 38 white British | 34 white Italians | 38 white Italians |
3 white non-British (Belgium, Italy, Romania) | 1 white non British (Turkey) | 6 white non-Italians (2 from Romania, 2 from Moldova, 1 from Kosowo, 1 Gipsy) | 1 white non-Italian (Romania) | |
1 African (Morocco) | 1 African (Egypt) | 1 African (Morocco) | ||
Disease location (Paris Classification [28]) | CD | CD | CD | CD |
2 L1 + L4a | 1 L1/2 L1 + L4a/1 L1 + L4b | 1 L1 | 2 L1/2 L1 + L4a | |
2 L2/4 L2 + L4a | 1 L2 + L4a | 5 L2/1 L2 + L4a | 1 L2/1 L2 + L4a | |
9 L3 + L4a/2 L3 + L4b | 3 L3/16 L3 + L4a | 3 L3/7 L3 + L4a | 10 L3/7 L3 + L4a | |
UC | UC | UC | UC | |
1 E1/2 E2 | 1 E1/2 E2 | 1 E1/7 E2 | 2 E1/4 E2 | |
1 E3/17E4 | 2 E3/11 E4 | 1 E3/14 E4 | 2 E3/9 E4 | |
CD behaviour (Paris Classification [28]) | 11 B1, 5 pB1 | 11 B1, 4 pB1 | 10 B1, 2 pB1 | 5 B1, 5pB1 |
1 B2 | 5 B2 | 1 B2, 1 pB2 | 10 B2, 1 pB2 | |
1B3 | 1 B3, 1 pB3 | 1pB3 | 1 pB3 | |
1pB2B3 | 1 B2B3, 1 pB2B3 | 1 B2B3, 1 pB2B3 | 1 B2B3 | |
CD growth (Paris Classification [28]) | 4 S1 | 3 S1 | 3 S1 | 2 S1 |
17 S0 | 13 S0 | 20 S0 | 15 S0 |
Data collection, clinical phenotype and outcome measurement
-
Abdominal pain: none, mild (can be ignored), severe (cannot be ignored);
-
Stool consistency of most stools: formed, partially formed, completely unformed;
-
Number of stools per 24 h: 0–2, 3–5, 6–8, >8;
-
Rectal bleeding: none, small amount only - in less than 50 % of stools, small amount with most stools, large amount (50 % of the stool content);
-
Nocturnal stools (any episode causing wakening);
-
Patient functioning - general well-being within the last week: no limitation of activities - well, occasional difficulties in maintaining age appropriate activities - below par, frequent limitation of activities - very poor;
-
Weight: weight gain or voluntary weight loss, involuntary weight loss 1–9 %, weight loss >10 %;
-
Height: < 1 channel decrease (or height velocity > − SD), > 1 <2 channel decrease (or height velocity < − 1 SD > − 2 SD), >2 channel decrease (or height velocity < −2 SD);
-
Abdomen on examination: no tenderness - no mass, tenderness - or mass without tenderness, tenderness - involuntary guarding - definite mass;
-
Peri-rectal disease: none - asymptomatic tags, 1–2 indolent fistula - scant drainage - tenderness of abscess, active fistula - drainage - tenderness or abscess;
-
Extra-intestinal manifestations including fever >38.5 for 3 days in a week, arthritis, uveitis, erythema nodosum, pyoderma gangrenosum: none, one, two;
Variables | All Group A vs Group B | Brita Group A vs Group B | Itab Group A vs Group B |
---|---|---|---|
A. Disease activity and location at presentation | |||
Disease activity | |||
CDc (PCDAId) | |||
Group A: mean ± SDe
| 38.75 ± 2.7 | 45 ± 3.3 | 31.3 ± 3.44 |
Group B:mean ± SD | 30.76 ± 2.02 | 32.2 ± 2.26 | 29.6 ± 3.5 |
P
|
0.05
|
0.003
|
0.7
|
UCf (PUCAIg) | |||
Group A: mean ± SD | 47.2 ± 2.5 | 55.2 ± 2.2 | 41.2 ± 2.7 |
Group B: mean ± SD | 41.4 ± 1.8 | 41.6 ± 2.5 | 39.8 ± 3.65 |
P
|
0.03
|
0.03
|
0.8
|
ORh
|
1.09
|
1.11
| 1.03 |
95 % CIi
|
1.02–1.1
|
1.03–1.2
| 1.01–1.08 |
Disease location | |||
CD | |||
P
|
0.3 for L1 |
0.6 for L1 |
0.3 for L1 |
0.05
for L2
|
0.04
for L2
|
0.7 for L2 | |
0.4 for L3 |
0.5 for L3 |
0.7 for L3 | |
UC | |||
P
|
0.7 for E1–E2 |
0.8 for E1–E2 |
0.6 for E1–E2 |
0.8 for E3–E4 |
0.9 for E3–E4 |
0.9 for E3–E4 | |
B. Biochemical parameters at disease presentation | |||
WBCj (x10^3/mm3) | |||
Group A: mean ± SD | 10.1 ± 0.45 | 10.9 ± 0.7 | 9.4 ± 0.6 |
Group B: mean ± SD | 8.81 ± 0.35 | 9.09 ± 0.5 | 8.5 ± 0.47 |
P
|
0.03
|
0.04
|
0.3
|
HCTk (%) | |||
Group A: mean ± SD | 33.7 ± 0.57 | 32.6 ± 0.6 | 34.8 ± 0.9 |
Group B: mean ± SD | 35.8 ± 0.5 | 34.9 ± 0.7 | 36.7 ± 0.6 |
P
|
0.005
|
0.02
|
0.09
|
Platelet count (x10^3/mm3) | |||
Group A: mean ± SD | 487 ± 18.9 | 476 ± 21.3 | 497.5 ± 31.2 |
Group B: mean ± SD | 393 ± 13.4 | 404 ± 18.6 | 382 ± 19.3 |
P
|
0.002
|
0.01
|
0.003
|
C. Disease course and outcomes | |||
Early treatment with thiopurines (within 3 months of diagnosis) | |||
Group A | 58 | 20 | 38 |
Group B | 46 | 17 | 29 |
P
|
0.05
|
0.7
|
0.006
|
OR |
1.86
| 1.04 |
7.19
|
95 % CI | 1.02–4.33 | 0.8–2.63 | 0.9–77.4 |
Relapses (per patient/per year of follow-up) | |||
Group A: mean ± SD | 1.4 ± 0.2 | 1.53 ± 1.24 | 1.03 ± 0.3 |
Group B: mean ± SD | 0.85 ± 0.1 | 0.9 ± 0.7 | 0.7 ± 0.13 |
P
|
0.05
|
0.005
|
0.3
|
OR |
1.2
|
1.5
|
1.2
|
95 % CI |
1.01–1.65
| 0.8–4.45 | 0.74–2.64 |
Number of endoscopies (per patient/per year of follow-up) | |||
Group A: mean ± SD | 0.9 ± 0.05 | 0.9 ± 0.06 | 0.9 ± 0.09 |
Group B: mean ± SD | 0.75 ± 0.05 | 0.8 ± 0.07 | 0.7 ± 0.08 |
P
|
0.04
|
0.2
|
0.05
|
OR |
1.67
|
1.2
|
7.07
|
95 % CI |
1.01–4.19
| 0.98–1.58 |
1.09–45.9
|
-
Haematocrit (%): <10 years of age (>33, 28–33, <28); 11–14 years of age/male (>35, 30–34, <30); 15–19 years of age/male (>37, 32–36, <32); 11–19 years of age/female (>37, 32–36, <32);
-
Erythrocyte sedimentation rate (ESR) (mm/h): <20, 20–50, >50;
-
Albumin (g/L): >35, 31–34, <30.
-
Incremental treatment escalation included: 5-Aminosalicilates (5-ASA), exclusive enteral nutrition (EEN), antibiotics, steroids, thiopurines, biologics (Infliximab, Adalimumab), surgical intervention;
-
Number of disease relapses per patient, per year of follow-up (definition of disease relapse as provided below in this paragraph);
-
Number of endoscopies per patient, per year of follow-up;
-
Number of unplanned inpatient and outpatient days, per patient, per year of follow-up.
Statistical analysis
-
The Chi-Square test was used as a test of association for categorical variables. It allowed us to identify the existence of a correlation between a categorical variable (e.g. perianal disease at diagnosis, per rectal bleeding at diagnosis etc.) and one of the two age groups;
-
For each categorical variable, a Fisher’s exact test was also used, given the small size of our cohort subsets;
-
An unpaired student t-test was used to compare continuous variables (e.g. laboratory parameters) with normal distribution and similar standard deviation between the two age groups, irrespective of sample size being equal between the groups;
-
Paired t-tests were used to compare the means of continuous variables between the two age groups, assuming a normal distribution but different standard deviations;
-
Welch’s adaptation of Student’s t test was used when the two samples had unequal variances and unequal sample sizes;
-
Mann – Whitney U test (or Wilcoxon rank-sum test) was used to compare continuous variables in the two groups, when the distribution was non-normal.