Patient demographics and clinical characteristics:
A total of 300 patients were included in the study (Figure 1). Their demographic and clinical characteristics are shown in Table 1. Patients were predominantly male (53.4%), native of Sarawak (53.0%), married (73.3%), non-vegetarian/vegan (95.0%) and non-regular alcohol consumers (98.0%). Hypertension (58.7%) was the commonest comorbid, followed by congestive cardiac failure (18.0%), diabetes mellitus (17.3%) and stroke (3.7%). The mean CHA2DS2-VASc score was 2.0 ± 1.3.
Table1: Demographic and clinical characteristic of patients on warfarin
Characteristics
|
Total patients, n = 300
|
Patients TTR (n, %)
|
p value
|
Good
73 (24.3)
|
Poor
227 (75.7)
|
Age (mean ± SD; 95% CI)
|
Years
|
59.7 ± 15.6;
57.9 – 61.5
|
57.2 ± 15.0; 53.7 – 60.7
|
60.5 ± 15.7;
58.5 – 62.6
|
0.559
|
Gender (n, %)
|
Male
|
172 (57.3)
|
39 (53.4)
|
133 (58.6)
|
0.438
|
Female
|
128 (42.7)
|
34 (46.6)
|
94 (41.4)
|
Ethnicity (n, %)
|
Malay
|
67 (22.3)
|
15 (20.5)
|
52 (22.9)
|
0.095
|
Chinese
|
68 (22.7)
|
32 (43.8)
|
44 (19.4)
|
Native
|
159 (53.0)
|
2 (2.7)
|
127 (55.9)
|
Others
|
6 (2.0)
|
2 (1.8)
|
4 (1.8)
|
Partner status (n, %)
|
No partner
|
80 (26.7)
|
18 (24.7)
|
62 (27.3)
|
0.420
|
With partner
|
220 (73.3)
|
55 (75.3)
|
165 (72.7)
|
Education (n, %)
|
None
|
58 (19.3)
|
6 (8.2)
|
52 (22.9)
|
0.001
|
Primary
|
101 (33.7)
|
19 (26.0)
|
82 (36.1)
|
Secondary
|
115 (38.3)
|
41 (56.2)
|
74 (32.6)
|
College/ Tertiary
|
26 (8.7)
|
7 (9.6)
|
19 (8.4)
|
Occupation (n, %)
|
Unemployed
|
147 (49.0)
|
30 (41.1)
|
117 (51.5)
|
0.269
|
Government dependent/ pensioner
|
72 (24.0)
|
19 (26.0)
|
53 (23.3)
|
Private
|
81 (27.0)
|
24 (32.9)
|
57 (25.1)
|
Diet (n, %)
|
Non–vegetarian/vegan
|
285 (95.0)
|
69 (94.5)
|
216 (95.2)
|
0.829
|
Vegetarian/vegan
|
15 (5.0)
|
4 (5.5)
|
11 (4.8)
|
Alcohol (n, %)
|
No
|
294 (98.0)
|
71 (97.3)
|
223 (98.2)
|
0.604
|
Yes
|
6 (2.0)
|
2 (2.7)
|
4 (1.8)
|
Comorbidities (n, %)
|
Congestive cardiac failure*
|
54 (18.0)
|
16 (21.9)
|
38 (16.7)
|
0.317
0.062
0.557
0.017
NA
0.164
|
Hypertension*
|
176 (58.7)
|
36 (49.3)
|
140 (61.7)
|
Diabetes mellitus*
|
52 (17.3)
|
11 (15.1)
|
41 (18.1)
|
Stroke/TIA/ /thromboembolism*
|
11 (3.7)
|
6 (8.2)
|
5 (2.2)
|
Vascular disease*
|
0
|
0
|
0
|
Others*
|
67 (22.3)
|
12 (16.4)
|
55 (24.2)
|
CHA2DS2-VASc
|
None
|
2.0 ± 1.3
1.8 – 2.1
|
1.8 ± 1.1
1.6 – 2.1
|
2.0 ± 1.4
1.9 – 2.2
|
0.204
|
Treatment duration
(mean ± SD; 95% CI)
|
Years
|
6.3 ± 6.5;
5.5 – 7.0
|
7.8 ± 8.3;
5.9 – 9.8
|
5.7 ± 5.7;
5.0 – 6.5
|
< 0.001
|
TTR (mean ± SD; 95% CI)
|
%
|
47.0 ± 17.3;
45.0 – 48.9
|
70.2 ± 8.7;
68.2 – 72.2
|
39.5 ± 11.9;
38.0 – 41.1
|
0.006
|
Hospitalization (n, %)
|
No
|
245 (81.7)
|
58 (79.5)
|
187 (82.4)
|
0.574
|
Yes
|
55 (18.3)
|
15 (20.5)
|
40 (17.6)
|
Abbreviations: TTR, time in therapeutic range; SD, standard deviation, 95% CI, 95% confidence interval.
* Each of the comorbidity is over total patients.
Figures in bold are statistically significant.
TTR:
In this study, patients had been receiving warfarin for a mean duration of 6.3 ± 6.5 years. Their mean TTR score was 47.0 ± 17.3%. Seventy-three (24.3%) patients had good TTR, with mean score of 70.2 ± 8.7%. The mean TTR for remaining 227 (75.5%) patients were significantly lower, 39.5 ± 11.9% (p = 0.006). Patients with good TTR had been receiving warfarin therapy for a significantly longer duration (mean, 7.8 ± 8.3 years versus 5.7 ± 5.7 years, p < 0.001). The education level was significantly different between patients with good and poor TTR (p = 0.001). 22.9% of patients with poor TTR were uneducated, while only 8.2% of patients with good TTR did not attend school. Even though stroke/TIA/thromboembolism was significantly more common in patients with good TTR (8.2% versus 2.2%, p = 0.017), the number of these patients was too small. Otherwise, there was no different in terms of patients’ gender, ethnicity, marital status, occupation, diet preference, alcohol intake and other comorbidities between patient with good and poor TTR.
QOL:
The overall PCS and MCS score were 47.0 ± 9.0 and 53.5 ± 9.6, respectively (Table 2). There was no significant difference in the score of PCS (48.3 ± 8.7 versus 46.5 ± 9.1, p = 0.150), MCS (53.4 ± 8.6 versus53.6 ± 9.7, p = 0.919) and each domain of SF-12v2 (p = 0.184 – 0.684) between patients with good and poor TTR, except for SF (51.5 ± 7.9 versus 48.2 ± 11.3, p = 0.019). The scores for PCS (48.2 ± 1.1 versus 46.6 ± 0.6, p = 0.175; 47.7 ± 1.1 versus 46.7 ± 0.6, p = 0.395), MCS (53.5 ± 1.1 versus 53.5 ± 0.6, p = 0.998; 53.6 ± 1.1 versus 53.5 ± 0.6, p = 0.951) and each domain of SF-12v2 (p = 0.207 – 0.737; p = 0.069 – 0.968) remained not significantly different between patients with good and poor TTR even after adjusted for treatment duration and education level, except for SF adjusted for treatment duration (51.9 ± 1.3 versus 48.1 ± 0.7, p = 0.014).
Table 2: Comparison of SF-12v2 score between patients with good and poor TTR
SF12v2 Parameters
|
Total score;
Mean ± SD;
95% CI
|
Without adjustment
|
Adjusted for duration*
|
Adjusted for education*
|
Good TTF
|
Poor TTF
|
p value
|
Good TTF
|
Poor TTF
|
p value
|
Good TTF
|
Poor TTF
|
p value
|
Mean ± SD;
95% CI
|
Mean ± SD; 95% CI
|
Mean ± SE; 95% CI
|
Mean ± SE; 95% CI
|
Mean ± SE; 95% CI
|
Mean ± SE; 95% CI
|
PCS
|
47.0 ± 9.0;
45.9 – 48.0
|
48.3 ± 8.7;
46.3 – 50.3
|
46.5 ± 9.1;
45.3 – 47.7
|
0.150
|
48.2 ± 1.1;
46.1 – 50.3
|
46.6 ± 0.6;
45.4 – 47.7
|
0.175
|
47.7 ± 1.1; 45.7 – 49.8
|
46.7 ± 0.6; 45.5 – 47.9
|
0.395
|
MCS
|
53.5 ± 9.6;
52.4 – 54.6
|
53.4 ± 8.6;
51.4 – 55.4
|
53.6 ± 9.7;
52.3 – 54.9
|
0.919
|
53.5 ± 1.1;
51.3 – 55.8
|
53.5 ± 0.6;
52.3 – 54.8
|
0.998
|
53.6 ± 1.1; 51.3 – 55.9
|
53.5 ± 0.6; 52.2 – 54.8
|
0.951
|
PF
|
47.0 ± 10.6;
45.8 – 48.2
|
48.0 ± 10.9;
45.5 – 50.6
|
46.7 ± 10.5;
45.3 – 48.1
|
0.358
|
47.9 ± 1.2;
45.5 – 50.4
|
46.7 ± 0.7;
45.3 – 48.1
|
0.399
|
47.4 ±1.2; 45.0 – 49.9
|
46.9 ± 0.7; 45.5 – 48.3
|
0.704
|
RP
|
48.2 ± 9.6;
47.1 – 49.3
|
48.6 ± 8.8;
46.5 – 50.6
|
48.1 ± 9.9;
46.8 – 49.4
|
0.684
|
48.6 ± 1.1;
46.3 – 50.8
|
48.1 ± 0.6;
46.8 – 49.3
|
0.698
|
48.2 ± 1.1; 46.0 – 50.5
|
48.2 ± 0.6; 46.9 – 49.4
|
0.968
|
BP
|
49.6 ± 10.5;
48.5 – 50.8
|
51.1 ± 9.5;
48.8 – 53.3
|
49.2 ± 10.7;
47.8 – 50.6
|
0.184
|
51.0 ± 1.2;
48.6 – 53.4
|
49.2 ± 0.7;
47.8 – 50.6
|
0.207
|
50.5 ± 1.2; 48.0 – 52.9
|
49.4 ± 0.7; 48.0 – 50.7
|
0.446
|
GH
|
47.6 ± 9.7;
46.5 – 48.7
|
47.9 ± 9.5;
45.7 – 50.1
|
47.5 ± 9.8;
46.2 – 48.8
|
0.730
|
47.9 ± 1.2;
45.7 – 50.2
|
47.5 ± 0.7;
46.2 – 48.8
|
0.737
|
48.1 ± 1.2; 45.8 – 50.4
|
47.4 ± 0.7; 46.2 – 48.7
|
0.639
|
V
|
56.3 ± 11.3;
55.0 – 57.6
|
56.9 ± 11.5;
54.2 – 59.6
|
56.1 ± 11.3;
54.6 – 57.6
|
0.602
|
57.0 ± 1.3;
54.3 – 59.6
|
56.1 ± 0.8;
54.6 – 57.5
|
0.561
|
57.1 ± 1.3; 54.5 – 59.7
|
56.0 ± 0.8; 54.5 – 57.5
|
0.505
|
SF
|
49.0 ± 10.7;
47.8 – 50.2
|
51.5 ± 7.9;
49.7 – 53.4
|
48.2 ± 11.3;
46.7 – 49.6
|
0.019
|
51.9 ± 1.3;
49.2 – 54.2
|
48.1 ± 0.7;
46.7 – 49.5
|
0.014
|
51.0 ±1.2; 48.5 – 53.4
|
48.3 ±0.7; 47.0 – 49.7
|
0.069
|
RE
|
48.8 ± 10.7;
47.6 – 50.0
|
48.2 ± 10.7;
45.7 – 50.7
|
49.0 ± 10.7;
47.6 – 50.4
|
0.563
|
48.1 ± 1.3;
45.6 – 50.6
|
49.0 ± 0.7;
47.6 – 50.4
|
0.523
|
48.2 ± 1.2; 45.7 – 50.7
|
49.0 ± 0.7; 47.6 – 50.4
|
0.607
|
MH
|
53.8 ± 9.9;
52.7 – 55.0
|
53.4 ± 9.3;
51.2 – 55.5
|
54.0 ± 10.1;
52.7 – 55.3
|
0.634
|
53.5 ± 1.2;
51.2 – 55.8
|
54.0 ± 0.7;
52.7 – 55.3
|
0.714
|
53.4 ± 1.2; 51.1 – 55.7
|
54.0 ± 0.7; 52.7 – 55.3
|
0.661
|
Abbreviations: SF12v2, Short Form 12v2 Health Survey; SD, standard deviation; 95% CI, 95% confidence interval; PCS, physical component summary; MCS, mental component summary; PF, physical functioning; RP, role–physical; BP, bodily pain; GH, general health perceptions; V, vitality; SF, social functioning; RE, role–emotional; MH, mental health.
*Adjusted with ANCOVA test
Figures in bold are statistically significant.
Treatment satisfaction:
The total score for DASS was 55.2 ± 21.3, while the score for L, H&B, as well as PPI were 18.0 ± 10.0, 15.6 ± 9.1 and 21.6 ± 5.9, respectively. The total DASS score was not significantly different between patients with good or poor TTR (54.6 ± 21.9 versus 55.4 ± 21.2, p = 0.779), even after adjusted for treatment duration (55.0 ± 2.5 versus 55.2 ± 1.4, p = 0.922) and education level (53.9 ± 2.5 versus 55.6 ± 1.4, p = 0.563). Similar non-significant difference was also reported in all the three DASS sub dimensions (p = 0.502 – 0.699), even after adjusted for treatment duration (p = 0.612 – 0.998) and education level (p = 0.419 – 0.864).
Table 3: Comparison of DASS score between patients with good and poor TTR.
DASS Parameters
|
Total score, Mean ± SD;
95% CI
|
Without adjustment
|
Adjusted for duration*
|
Adjusted for education*
|
Good TTF
|
Poor TTF
|
p value
|
Good TTF
|
Poor TTF
|
p value
|
Good TTF
|
Poor TTF
|
p value
|
Mean ± SD;
95% CI
|
Mean ± SD; 95% CI
|
Mean ± SE; 95% CI
|
Mean ± SE; 95% CI
|
Mean ± SE; 95% CI
|
Mean ± SE; 95% CI
|
Total
|
55.2 ± 21.3;
52.6 – 57.6
|
54.6 ± 21.9;
49.5 – 59.7
|
55.4 ± 21.2;
52.6 – 58.1
|
0.779
|
55.0 ± 2.5;
50.0 – 59.9
|
55.2 ± 1.4;
52.5 – 58.0
|
0.922
|
53.9 ± 2.5; 48.9 – 58.9
|
55.6 ± 1.4; 52.8 – 58.4
|
0.563
|
L
|
18.0 ± 10.0;
16.9 – 19.1
|
18.4 ± 10.5;
15.9 – 20.8
|
17.9 ± 9.8;
16.6 – 19.1
|
0.699
|
18.5 ± 1.2;
16.2 – 20.8
|
17.8 ± 0.7;
16.5 – 19.1
|
0.998
|
17.8 ± 1.2; 15.5 – 20.1
|
18.0 ± 0.7; 16.7 – 19.3
|
0.864
|
H&B
|
15.6 ± 9.1;
14.5 – 16.6
|
14.9 ± 8.4;
13.0 – 16.9
|
15.8 ± 9.4;
14.5 – 17.0
|
0.502
|
15.1 ± 1.1;
13.0 -17.3
|
15.7 ± 0.6;
14.5 – 16.9
|
0.655
|
14.8 ± 1.1; 12.6 – 16.9
|
15.8 ± 0.6; 14.6 – 17.0
|
0.419
|
PPI
|
21.6 ± 5.9;
21.0 – 22.3
|
21.3 ± 6.3;
19.8 – 22.7
|
21.8 ± 5.8;
21.0 – 22.5
|
0.531
|
21.3 ± 0.7;
19.9 – 22.7
|
21.7 ± 0.4;
21.0 – 22.5
|
0.612
|
21.3 ± 0.7; 19.9 – 22.7
|
21.7 ± 0.4; 21.0 – 22.5
|
0.589
|
Abbreviations: DASS, Duke Anticoagulant Satisfaction Scale; SD, standard deviation; 95% CI, 95% confidence interval; L, limitations; H&B, hassles and burdens; PPI, positive psychological impacts.
*Adjusted with ANCOVA test
Hospitalisation and complications:
Fifty-five (18.3%) patients had been admitted to hospital due to complications of warfarin, all attributed to bleeding tendency. The hospitalisation rate was not significantly different between patients with good and poor TTR (20.5% versus 17.6%, p = 0.574).