Increasing newly diagnosed IBD
At first, 4114 cases were extracted from the administrative database. After data review, 1346 cases were excluded because IBD was not the primary discharge diagnosis, and 1301 cases were excluded because of repeated admissions.
At last, a total of 1467 cases were included in the final analysis, including 898 cases of UC (61.21%) and 569 cases of CD (38.79%). As shown in Table 1, the male ratio of patients with UC was lower than that of patients with CD (1.11:1 vs 1.96:1, P<0.001). The average age at admission was younger in patients with UC compared with patients with CD (41.95±15.36 years vs 37.62±15.04 years, P<0.001). The peak age at admission in patients with UC and CD was 30-39 years old and 20-29 years old, respectively.
Table 1. Characteristics of patients with IBD
|
IBD
|
UC
|
CD
|
|
|
N=1467
|
N=898
|
N=569
|
P
|
Sex, n (%)
|
|
|
|
|
Male
|
849 (57.87)
|
472 (52.56)
|
377 (66.26)
|
<0.001
|
Female
|
618 (42.13)
|
426 (47.44)
|
192 (33.74)
|
|
Age, years
|
40.27±15.38
|
41.95±15.36
|
37.62±15.04
|
<0.001
|
0-9
|
8 (0.55)
|
7 (0.78)
|
1 (0.18)
|
|
10-19
|
98 (6.68)
|
43 (4.79)
|
55 (9.67)
|
|
20-29
|
338 (23.04)
|
180 (20.04)
|
158 (27.77)
|
|
30-39
|
321 (21.88)
|
201 (22.38)
|
120 (21.09)
|
|
40-49
|
285 (19.43)
|
178 (19.82)
|
107 (18.80)
|
|
50-59
|
225 (15.34)
|
152 (16.93)
|
73 (12.83)
|
|
60-69
|
135 (9.20)
|
97 (10.80)
|
38 (6.68)
|
|
70-79
|
51 (3.48)
|
37 (4.12)
|
14 (2.46)
|
|
>80
|
6 (0.41)
|
3 (0.33)
|
3 (0.53)
|
|
The numbers of newly diagnosed patients with UC and CD increased significantly during the last 30 years. The newly diagnosed cases of UC increased from 41 cases in 1986-1990 to 373 cases in 2011-2015 (r=0.918, P<0.05). The newly diagnosed cases of CD increased from 16 cases in 1986-1990 to 276 cases in 2011-2015 (r=0.898, P<0.05).
Improving prognosis of newly diagnosed IBD
A total of 20 patients died in this study, including 9 cases of UC (1.00%) and 11 case of CD (1.93%). The reasons for death included septic shock (7 cases, 35%), haemorrhagic shock (5 cases, 25%), multiple organ failure syndrome (4 cases, 20%), toxic megacolon (2 cases, 10%) and intestinal perforation (2 cases, 10%). The in-hospital mortality for patients with UC decreased from 2.4% in 1986-1990 to 0.3% in 2011-2015 (r=-0.827, P<0.05). The in-hospital mortality for patients with CD decreased from 12.5% in 1986-1990 to 1.8% in 2011-2015 (r=-0.978, P<0.05).
A total of 277 cases received operations, including 106 cases of UC (11.8%) and 171 cases of CD (30.1%). An increasing trend in the annual operation rate was observed in patients with UC (r=0.956, P<0.05), while a decreasing trend in the annual operation rate was observed patients with CD (r=-0.847, P<0.05).
Shortened average lengths of hospital stay were observed both in patients with UC and CD (UC, from 47.83±34.35 days to 23.58±20.05 days, r=-0.970, P<0.05; CD, from 65.50±50.57 days to 26.41±18.43 days, r=-0.913, P<0.05).
Complications of IBD
As shown in Table 2, toxic megacolon (16 cases, 1.78%) was the most common severe complication of UC, followed by intestinal perforation (13 cases, 1.45%), intestinal obstruction (9 case, 1.00%), intestinal fistula (5 cases, 0,56%) and haemorrhagic shock (3 cases, 0.33%). Intestinal obstruction was the most common severe complication of CD (128 cases, 22.5%), followed by intestinal fistula (85 cases, 14.94%), intestinal perforation (27 cases, 4.75%) and haemorrhagic shock (5 cases, 0.88%). The annual proportion of complications varied from 34.62% to 39.68% during the study period in newly diagnosed patients with CD and varied from 3.70% to 7.32% in newly diagnosed patients with UC. No significant trend was observed in the proportion of complications in UC and CD.
Table 2. Complications in patients with UC and CD
|
All
|
UC
|
CD
|
|
|
N=2315
|
N=1313
|
N=1002
|
P
|
Intestinal obstruction, n (%)
|
137 (9.34)
|
9 (1.00)
|
128 (22.50)
|
<0.001
|
Intestinal perforation, n (%)
|
40 (2.73)
|
13 (1.45)
|
27 (4.75)
|
<0.001
|
Intestinal fistula, n (%)
|
90 (6.13)
|
5 (0.56)
|
85 (14.94)
|
<0.001
|
Toxic megacolon, n (%)
|
16 (1.09)
|
16 (1.78)
|
0 (0.00)
|
<0.001
|
Haemorrhagic shock, n (%)
|
8 (0.55)
|
3 (0.33)
|
5 (0.88)
|
0.168
|
Risk factors for prognosis in IBD
As shown in Table 3, multivariable regression analysis showed that year of admission, toxic megacolon, septic shock and haematological comorbidities were independent risk factors for death in patients with UC. Intestinal fistula, intestinal perforation and septic shock were independent risk factors for surgery in patients with CD.
Table 3. Multivariable regression analysis of risk factors for in-hospitality death in IBD
Characteristics
|
β
|
SE
|
Wald
|
P
|
UC
|
|
|
|
|
Year of admission
|
-1.111
|
0.3
|
13.671
|
<0.001
|
Age at admission
|
0.075
|
0.032
|
5.474
|
<0.05
|
Toxic megacolon
|
7.393
|
2.907
|
6.47
|
<0.05
|
Septic shock
|
7.188
|
2.673
|
7.232
|
<0.05
|
Haematological comorbidities
|
6.137
|
1.734
|
12.524
|
<0.001
|
Constant
|
-5.291
|
2.696
|
3.851
|
0.05
|
CD
|
|
|
|
|
Year of admission
|
-0.940
|
0.310
|
9.217
|
0.002
|
Intestinal fistula
|
2.454
|
1.128
|
4.736
|
0.030
|
Intestinal perforation
|
3.460
|
1.325
|
6.819
|
0.009
|
Note: β short for β regression coefficient; SE short for standard error; Wald short for Wald χ2 test.
As shown in Table 4, intestinal obstruction, intestinal perforation, canceration, toxic megacolon and haemorrhagic shock were independent risk factors for surgery in patients with UC. Intestinal fistula, intestinal obstruction and intestinal perforation were independent risk factors for surgery in patients with CD.
Table 4. Multivariable regression analysis of risk factors for operation in IBD
Characteristics
|
β
|
SE
|
Wald
|
P
|
UC
|
|
|
|
|
Age
|
0.018
|
0.007
|
7.239
|
<0.05
|
Intestinal obstruction
|
2.304
|
0.527
|
19.09
|
<0.001
|
Intestinal Perforation
|
4.001
|
0.835
|
22.947
|
<0.001
|
Toxic megacolon
|
2.317
|
1.031
|
5.054
|
<0.05
|
Haemorrhagic shock
|
2.707
|
1.013
|
7.141
|
<0.05
|
Canceration
|
3.735
|
1.107
|
11.393
|
<0.05
|
Septic shock
|
2.835
|
0.956
|
8.793
|
<0.05
|
Constant
|
-3.586
|
0.635
|
31.915
|
<0.001
|
CD
|
|
|
|
|
Year of admission
|
-0.270
|
0.078
|
11.894
|
0.001
|
Intestinal fistula
|
0.765
|
0.291
|
6.923
|
0.009
|
Intestinal obstruction
|
1.114
|
0.238
|
21.947
|
0.000
|
Intestinal perforation
|
1.615
|
0.625
|
6.680
|
0.010
|
Note: β short for β regression coefficient; SE short for standard error; Wald short for Wald χ2 test.