The demographic and psychological characteristic of 530 gout patients, 174 AS patients, 60 RA patients, and 324 healthy controls matched by education were presented in Additional file 1. The gout patients and healthy controls were also matched by age and gender (p > 0.05). After comparing the psychological variables, the LOT-R score of gout patients was higher than AS and RA patients (p < 0.05). There was no significant difference of the LOT-R score between the gout patients and the healthy controls (p > 0.05). The SAS and SDS score of gout patients were lower than AS and RA patients (p < 0.05), while the SDS score of gout patients was higher than healthy controls (p < 0.05).
The clinical characteristic of 530 patients were shown in Table 1. More than half of the patients were male (96.4%) and living in the city (70.9%). Most patients suffered from comorbidity (62.1%) and nearly a quarter of patients had tophi (24.5%). The mean disease duration and VAS score were 5.0 (2.0-7.3) years and 2.0 (0.0–4.0). Among the 530 gout patients, only 320 gout patients (60.4%) returned and retested the SUA in 90 days, while 55.1% of all gout patients had an MPR < 0.8.
Table 1
Demographic and clinical characteristic of 530 gout patients
Variables
|
Gout patients(n = 530)
|
Age, years, mean (SD)
|
41.4 (12.3)
|
Gender, male, n (%)
|
511 (96.4)
|
BMI, kg/m2, mean (SD)
|
25.8 (3.7)
|
Years of education
|
|
≤ 9 years n (%)
|
318 (60.0)
|
> 9 years n (%)
|
212 (40.0)
|
Residence
|
|
City, n (%)
|
376 (70.9)
|
Countryside, n (%)
|
154 (29.1)
|
Stage of gout
|
|
Acute phase, n (%)
|
36 (6.8)
|
Others: intercritical phase or chronic phase, n (%)
|
494 (93.2)
|
Disease duration, years, mean (IQR)
|
5.0 (2.0-7.3)
|
Tophi, n (%)
|
130 (24.5)
|
Comorbidity, n (%)
|
329 (62.1)
|
Hypertension, n (%)
|
94 (17.7)
|
Diabetes, n (%)
|
38 (7.2)
|
Hyperlipidemia, n (%)
|
267 (50.4)
|
CKD, n (%)
|
72 (13.6)
|
VAS, mean (IQR)
|
2.0 (0.0–4.0)
|
Baseline SUA, µmol/L, mean (SD)
|
501.1 (147.1)
|
Follow-up patients, n, (%)
|
330 (60.4)
|
Follow-up SUA, µmol/L, mean (SD)a
|
363.3 (46.3)
|
At SUA target, n (%)a
|
127 (40.0)
|
ULT drugs
|
|
Febuxostat, n (%)
|
404 (76.2)
|
Allopurinol, n (%)
|
43 (8.1)
|
Benzbromarone, n (%)
|
26 (4.9)
|
Others, n (%)
|
57 (10.8)
|
ULT compliance
|
|
MPR < 0.8, n (%)
|
292 (55.1)
|
MPR ≥ 0.8, n (%)
|
238 (44.9)
|
SD standard deviation, and the data that meet the normal distribution are shown as mean (SD), BMI body mass index, IQR interquartile range, and the data that did not meet the normal distribution are shown as median (IQR), CKD chronic kidney disease, VAS visual analog scale, SUA serum uric acid, ULT urate lowering therapy, MPR medication possession ratio
a base on the 320 patients that returned and retested the SUA during the observed day
In this study, the 530 gout patients were divided into four subgroups according to their compliance to ULT and the stage of gout, which were displayed in Additional file 2. Patients with poor compliance had a higher concentration of baseline SUA, VAS, and LOT-R score and lower SAS and SDS score (p < 0.05). Besides, poor
compliance was also related to education, residence, tophi, and hyperlipidemia (p < 0.05). Finally, patients suffering acute gout attack were found to have higher VAS and SAS score (p < 0.05). The stage of gout was not associated with optimism in this study (p > 0.05).
The result of the Spearman correlation analysis was shown in Table 2. Among the 530 gout patients, baseline SUA and disease duration positively correlated with the LOT-R score, while the relationship between the MPR of ULT therapy and LOT-R score was negative (p < 0.05). Meanwhile, the SAS score positively correlated with VAS (p < 0.05).
Table 2
Correlations between psychological and demographic, clinical characteristic of gout patients
Variables
|
LOT-R score
|
SAS score
|
SDS score
|
r
|
p value
|
r
|
p value
|
r
|
p value
|
Age
|
0.000
|
0.994
|
0.081
|
0.063
|
0.057
|
0.191
|
BMI
|
0.064
|
0.149
|
0.012
|
0.792
|
-0.027
|
0.543
|
Disease duration
|
-0.106
|
0.015
|
-0.015
|
0.735
|
0.034
|
0.439
|
VAS
|
0.034
|
0.432
|
0.154
|
< 0.001
|
0.052
|
0.228
|
Baseline SUA
|
0.131
|
0.003
|
0.024
|
0.578
|
0.018
|
0.671
|
MPR
|
-0.536
|
< 0.001
|
0.038
|
0.382
|
0.044
|
0.313
|
LOT-R score
|
1
|
|
-0.123
|
0.005
|
-0.251
|
< 0.001
|
SAS score
|
-0.123
|
0.005
|
1
|
|
0.498
|
< 0.001
|
SDS score
|
-0.251
|
< 0.001
|
0.498
|
< 0.001
|
1
|
|
LOT-R life orientation test-revised, SAS self-rating anxiety scale, SDS self-rating depression scale, BMI body mass index, VAS visual analog scale, SUA serum uric acid, MPR medication possession ratio
The result of stepwise multiple and binary and regression analysis were shown in Table 3 and Table 4. All factors with p < 0.05 in the univariate analysis were included in the models. Insufficient education (p < 0.001) contributed to optimism in gout patients. Besides, insufficient education (p = 0.046), living in countryside (p = 0.002), high concentration of SUA (p = 0.001) and LOT-R score (p < 0.001) contributed to poor compliance to ULT.
Table 3
Stepwise multiple regression analysis of LOT-R score in gout patients
Variables
|
B
|
SE
|
OR
|
OR%95CI
|
p value
|
Years of education
|
|
|
|
|
|
≤ 9 years
|
1.394
|
0.371
|
0.249
|
0.120–0.513
|
< 0.001
|
LOT-R life orientation test-revised, B beta, SE standard error, OR odds ratio, CI confidence interval
Model included all factors with p < 0.05 in the Spearman analysis except SAS and SDS score
Table 4
Stepwise binary regression analysis of MPR < 0.8 in gout patients
Variables
|
B
|
SE
|
OR
|
OR%95CI
|
p value
|
Years of education
|
|
|
|
|
|
≤ 9 years
|
0.394
|
0.198
|
0.674
|
0.457–0.994
|
0.046
|
Residence
|
|
|
|
|
|
Countryside
|
0.659
|
0.217
|
1.934
|
1.265–2.956
|
0.002
|
SUA
|
0.002
|
0.001
|
1.002
|
1.001–1.004
|
0.001
|
LOT-R
|
0.376
|
0.048
|
1.457
|
1.325–1.602
|
< 0.001
|
MPR medication possession ratio, B beta, SE standard error, OR odds ratio, CI confidence interval, SUA serum uric acid, LOT-R life orientation test-revised
Model included all factors with p < 0.05 in the univariate analysis