We enrolled 652 patients with AS who were followed up for at least 1 year before and after their first ASDAS assessment (Figure 1) and compared the number of outpatient visits and average visit time within one year before and after the initial ASDAS assessment. We identified 201 AS patients who received ≥ 3 continuous ASDAS assessment with at an interval of 3 months and compared the results of the second and third ASDAS assessments with those of the first.
Basline characterisitics
The mean age of the 652 eligible patients with AS at their first assessment on the EMRMS was 43.1 ± 13.7 years, and 475 patients were men (72.9%). The AS onset age distribution was 26.8 ± 11.5 years, the disease duration was 16.4 ± 11.7 years, 430 patients were HLA-B27 positive (66%), and 203 were undergoing biologic treatment (31.1%). The most common comorbidity was hypertension (131 patients, 20.1%), the most common AS symptom was uveitis (168 patients, 25.8%), and the most common cause of arthropathy was fracture (70 patients, 10.7%; Table 1).
The mean age of the 201 eligible patients with AS and more than three consecutive assessments on the EREMS was 43.3 ± 13.4 years. In all, 148 were men (73.6%), the AS onset age distribution was 27.0 ± 11.2 years, the disease duration was 16.3 ± 11.6 years, 136 were HLA-B27 positive (67.6%), and 49 were undergoing biologic treatment (24.4%). The most common comorbidity was hypertension (131 patients, 20.1%), the most common AS symptom was uveitis (43 patients, 21.4%), and the most common cause of arthropathy was fracture (15 patients, 7.5%; Table 1).
Table 1
Baseline characteristics of eligible patients with AS obtained using the electronic medical record management system for ASDAS assessment
|
Eligible AS patients, n=652
|
Eligible AS patients with ≥ 3 continuous assessment, n=201
|
Age, years (Mean ± SD)
|
43.1±13.7
|
43.3±13.4
|
Gender
|
|
|
Female
|
177 (27.1)
|
53 (26.4)
|
Male
|
475 (72.9)
|
148 (73.6)
|
AS Age, years (Mean ± SD)
|
26.8±11.5
|
27.0±11.2
|
Disease duration, years (Mean ± SD)
|
16.4±11.7
|
16.3±11.6
|
HLA-B27 positive
|
430 (66.0)
|
136 (67.7)
|
Biologics therapy
|
203 (31.1)
|
49 (24.4)
|
Co-morbidities
|
|
|
Hypertension
|
131 (20.1)
|
43 (21.4)
|
Diabetes mellitus
|
48 (7.4)
|
9 (4.5)
|
Hyperlipidemia
|
96 (14.7)
|
32 (15.9)
|
Hepatitis B
|
71 (10.9)
|
19 (9.5)
|
Hepatitis C
|
15 (2.3)
|
6 (3.0)
|
Renal insufficiency
|
21 (3.2)
|
4 (2.0)
|
Gout
|
29 (4.4)
|
6 (3.0)
|
Coronary artery disease
|
21 (3.2)
|
7 (3.5)
|
Stroke
|
2 (0.3)
|
1 (0.5)
|
Periodontitis
|
121 (18.6)
|
39 (19.4)
|
Osteoporosis
|
42 (6.4)
|
12 (6.0)
|
Tuberculosis history
|
45 (6.9)
|
12 (6.0)
|
AS symptoms
|
|
|
Uveitis
|
168 (25.8)
|
53 (26.4)
|
Psoriasis
|
44 (6.7)
|
22 (10.9)
|
Crohn's disease
|
0 (0.0)
|
1 (0.5)
|
Ulcerative colitis
|
3 (0.5)
|
2 (1.0)
|
Peripheral arthritis
|
125 (19.2)
|
43 (21.4)
|
Enthesitis
|
92 (14.1)
|
36 (17.9)
|
Dactylitis
|
15 (2.3)
|
4 (2.0)
|
Family history
|
|
|
AS-First degree relatives
|
119 (18.3)
|
30 (14.9)
|
AS-Secondary degree relatives
|
185 (28.4)
|
48 (23.9)
|
Psoriasis
|
27 (4.1)
|
10 (5.0)
|
Psoriatic arthritis
|
4 (0.6)
|
2 (1.0)
|
Uveitis
|
30 (4.6)
|
12 (6.0)
|
Crohn’s disease
|
0 (0.0)
|
0 (0.0)
|
Ulcerative colitis
|
2 (0.3)
|
1 (0.5)
|
Rheumatoid arthritis
|
38 (5.8)
|
11 (5.5)
|
Systemic Lupus Erythematosus
|
19 (2.9)
|
5 (2.5)
|
Sicca syndrome
|
16 (2.5)
|
6 (3.0)
|
Past history
|
|
|
Total hip replacement
|
25 (3.8)
|
4 (2.0)
|
Total knee replacement
|
4 (0.6)
|
1 (0.5)
|
Fracture
|
70 (10.7)
|
15 (7.5)
|
Palindromic rheumatism
|
7 (1.1)
|
1 (0.5)
|
Abbreviations: AS: ankylosing spondylitis, ASDAS, Ankylosing Spondylitis Disease Activity Score
Primary outcomes
After the first assessment on the EREMS within 1 year, the frequency of outpatient visits increased from 5.4 ± 3.4 to 5.8 ± 3.5 (p < 0.001), particularly in patients with a high disease activity (ASDAS-CRP, 5.1 ± 3.2 vs 5.9 ± 3.5, p < 0.001 and ASDAS-ESR, 5.4 ± 3.5 vs 6.2 ± 3.7, p < 0.001) and very high disease activity (ASDAS-CRP, 5.7 ± 3.4 vs 8.7 ± 4.0, p < 0.001 and ASDAS-ESR, 5.6 ± 3.6 vs 8.4 ± 3.9, p = 0.002). The duration of outpatient visits decreased from 9.2 ± 4.4 to 8.7 ± 3.8 min, (p = 0.03), especially in those with an inactive disease (ASDAS-CRP, 9.2 ± 4.2 vs 8.5 ± 3.3 min, p = 0.022; ASDAS-ESR, 9.1 ± 4.2 vs 8.4 ± 3.3 min, p = 0.024; Table 2).
Table 2
Frequency and time of outpatient visits before and after the first EMRMS assessment (n = 652)
Analysis population
|
ASDAS
|
Number
|
Frequency of outpatient visits
(mean ± SD)
|
P value
|
Time of outpatient visits (minutes)
(mean ± SD)
|
P value
|
One year before assessment
|
One year after assessment
|
One year before assessment
|
One year after assessment
|
CRP
|
<1.3
|
211
|
5.5±3.4
|
5.6±3.4
|
0.485
|
9.2±4.2
|
8.5±3.3
|
0.022
|
1.3 - <2.1
|
245
|
5.4±3.4
|
5.6±3.4
|
0.311
|
9.3±4.8
|
9.0±4.4
|
0.278
|
2.1 - 3.5
|
170
|
5.1±3.2
|
5.9±3.5
|
<0.001
|
8.7±4.1
|
8.5±3.4
|
0.554
|
>3.5
|
26
|
5.7±3.4
|
8.7±4.0
|
<0.001
|
9.6±4.1
|
9.8±2.7
|
0.827
|
ESR
|
<1.3
|
195
|
5.4±3.2
|
5.4±3.1
|
0.878
|
9.1±4.2
|
8.4±3.3
|
0.024
|
1.3 - <2.1
|
258
|
5.3±3.4
|
5.5±3.4
|
0.160
|
8.9±4.2
|
8.5±4.1
|
0.214
|
2.1 - 3.5
|
174
|
5.4±3.5
|
6.2±3.7
|
<0.001
|
9.3±4.6
|
9.4±3.7
|
0.961
|
>3.5
|
25
|
5.6±3.6
|
8.4±3.9
|
0.002
|
11.0±4.5
|
9.3±2.9
|
0.124
|
Total
|
652
|
5.4±3.4
|
5.8±3.5
|
<0.001
|
9.2±4.4
|
8.7±3.8
|
0.030
|
*P value from a paired t test
Abbreviations: ASDAS, Ankylosing Spondylitis Disease Activity Score; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate
Secondary outcomes
The ASDAS-CRP and ASDAS-ESR were improved between the first and third consecutive assessment (1.6 ± 0.8, 1.5 ± 0.8, p = 0.040 and 1.6 ± 0.8, 1.5 ± 0.7, p = 0.089, respectively), but only the ASDAS-CRP reached significant difference (Table 3).
Table 3
ASDAS-CRP and ASDAS-ESR from three consecutive assessments (n = 201).
|
First
assessment
|
Second
assessment
|
Third
assessment
|
P-value*
|
1st vs 2nd
|
2nd vs 3rd
|
1st vs 3rd
|
ASDAS-CRP
|
Mean ±SD
|
1.6±0.8
|
1.5±0.8
|
1.5±0.8
|
0.122
|
0.631
|
0.040
|
Q2 (Q1-Q3)
|
1.5 (0.9–2.1)
|
1.3 (0.9–1.9)
|
1.4 (0.8–1.9)
|
|
|
|
ASDAS-ESR
|
Mean ±SD
|
1.6±0.8
|
1.5±0.7
|
1.5±0.7
|
0.243
|
0.537
|
0.089
|
Q2 (Q1-Q3)
|
1.4 (1.1–2.0)
|
1.5 (1.0–2.0)
|
1.4 (1.0–1.9)
|
|
|
|
*Statistical analysis was conducted using a paired t test
Abbreviations: ASDAS, Ankylosing Spondylitis Disease Activity Score; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate
†Comorbidities were identified within 1 year before the index date.
†Three consecutive times: the earliest time was considered the first time, the second time was 84 ± 7 days, and the third time was 168 ± 7 days