Characteristics of 194 patients were reported in Table 2. The average age of patients was 53.4 ± 11.4 years old. Majority of them (78.4%) had monthly income of less than 5,000 baht (30 baht ≈ 1$). About 63% graduated with primary school or lower. With respect to treatment status, 50% were disease free while 30% were receiving treatment as concurrent chemo radiation therapy (CCRT), and 20% were in disease progression after completed CCRT, respectively. Among patients who were receiving treatment, there were 9 (15.2%), 26 (44.1%), 21 (35.6%) and 3 (5.1%) patients with stage IB3-IIA2, IIB, IIIB and IVA, respectively. The three most common symptoms among patients who were in treatment stage were abnormal vaginal bleeding (AVB) (78.0%), abnormal discharge (28.9%) and pelvic pain (27.1%), respectively. For patients in progression stage, back pain (39.5%), abdominal pain (23.7%) and AVB (15.8%) were the three most common symptoms. Back pain (23.7%), mild radiation proctitis (9.3%) and cystitis (3.1%) were the most common symptoms reported by patients with disease free.
Table 2
General and clinical characteristics of the patients (n = 194)
Characteristics
|
Number
|
(%)
|
Age, mean )SD(, range
|
53.4(11.4), 29–80
|
Education level
|
|
|
|
Primary school or below
|
122
|
62.9
|
|
Secondary school
|
45
|
23.2
|
|
Diploma
|
6
|
3.1
|
|
Bachelor or higher
|
21
|
10.8
|
Occupation
|
|
|
|
Unemployed
|
87
|
44.9
|
|
Self-employed
|
81
|
41.8
|
|
Paid-employed
|
20
|
10.3
|
|
Government officer
|
3
|
1.5
|
|
Others
|
3
|
1.5
|
Average income per month)Baht(
|
|
|
|
< 5,000
|
152
|
78.4
|
|
5,000–10,000
|
14
|
7.2
|
|
10,001–20,000
|
17
|
8.8
|
|
20,001–30,000
|
9
|
4.6
|
|
> 30,000
|
2
|
1.0
|
Health insurance coverage
|
|
|
|
Universal Coverage Scheme
|
111
|
57.2
|
|
Social Security Scheme
|
57
|
29.4
|
|
Civil Servant Medical Benefit Scheme
|
13
|
6.7
|
|
Self-pay
|
10
|
5.2
|
|
Other
|
3
|
1.5
|
Treatment status
|
|
|
|
Treatment
|
59
|
30.4
|
|
Disease free
|
97
|
50.0
|
|
Progression
|
38
|
19.6
|
Clinical stage (for patients who receiving treatment)
|
|
|
|
IB3-IIA2
|
9
|
15.2
|
|
IIB
|
26
|
44.1
|
|
IIIB
|
21
|
35.6
|
|
IVA
|
3
|
5.1
|
Presence of symptom
|
|
|
|
No symptom
|
64
|
32.9
|
|
1 symptom
|
77
|
39.7
|
|
> 1 symptoms
|
53
|
27.4
|
SD standard deviation |
The mean, standard deviation, and median of utility values obtained from the 6 approaches were displayed in Fig. 1. The mean (SD) values of the 6 utilities were, from low to high, 0.755 ± 0.248 (EQ-5D-3L), 0.801 ± 280 (TTO), 0.806 ± 0.156 (VAS), 0.871 ± 0.184 (cTTO model), 0.875 ± 0.168 (Hybrid model), and 0.900 ± 0.142 (DCE model). Significant difference in terms of utility scores across the 6 approaches was identified in Table 3. According to the Wilcoxon signed rank test, we found that all pairs were statistical different except the following 2 pairs: TTO-VAS; and EQ-5D-5L (Hybrid model)-EQ-5D-5D (cTTO model). As shown in Fig. 1, the overall ceiling effect was 20.1% for VAS, 39.2% for EQ-5D-3L, and 32.5% for EQ-5D-5L. It should be noted that floor effect was not observed in our study.
Table 3
Comparison of utility scores across the 6 approaches
Utility: mean (SD)/ median (range)a
|
P-value*
|
EQ-5D-3L
|
VAS
|
TTO
|
EQ-5D-5L (cTTO model)
|
EQ-5D-5L (DCE model)
|
EQ-5D-5L (Hybrid model)
|
0.755(0.248)
/0.726
(-0.085-1)
|
0.806(0.156)
/0.800
(0.300-1)
|
0.801(0.280)
/0.950
(0.100–0.950)
|
0.871(0.184)
/0.938
(0.031–0.959)
|
0.900(0.142)
/0.952
(0.256–0.965)
|
0.875(0.168)
/0.934
(0.140–0.944)
|
< 0.001
|
SD standard deviation, EQ-5D-3L Euro-Quality of life five-dimension-three level, EQ-5D-5L Euro-Quality of life five-dimension-five level, VAS visual analog scale, TTO time trade-off, cTTO composite time-trade-off, DCE discrete choice experiment |
*Friedman test. Significant difference across the 6 approaches (P < 0.001) |
aWilcoxon signed rank test revealed significant difference across each pairwise comparison except the following 2 pairs; TTO –VAS, EQ-5D-5L (cTTO model) – EQ-5D-5L (Hybrid model) |
Agreement
Table 4 show ICCs between the 6 different approaches. Poor agreement (ICC < 0.5) were observed among the following pairs; TTO- EQ-5D-5L (cTTO model), TTO-EQ-5D-5L (DCE model), TTO- EQ-5D-5L (Hybrid model). Moderate agreement (ICC: 0.5–0.74) was observed among EQ-5D-3L-VAS, EQ-5D-3L-TTO, VAS-TTO, VAS-cTTO model, VAS-DCE model, and VAS-Hybrid model. On the other hand, good agreement (ICC > 0.75) was observed between EQ-5D-3L-EQ-5D-5L, and among 3 EQ-5D-5L approaches (cTTO model-DCE model, cTTO model-Hybrid model, DCE model-Hybrid model)
Table 4
Agreement of utility values between the 6 approaches using intraclass correlation coefficient
Approach
|
Intraclass correlation coefficient (95% Confidence interval)*
|
EQ-5D-3L
|
VAS
|
TTO
|
EQ-5D-5L
(cTTO model)
|
EQ-5D-5L
(DCE model)
|
EQ-5D-5L
(Hybrid model)
|
EQ-5D-3L
|
-
|
0.594
(0.459–0.695)
|
0.525
(0.372-
0.642)
|
0.849
(0.354-
0.939)
|
0.749
(0.088-
0.896)
|
0.832
(0.306-
0.932)
|
VAS
|
|
-
|
0.515
(0.356-
0.635)
|
0.609
(0.451-
0.718)
|
0.561
(0.262-
0.721)
|
0.615
(0.442-
0.728)
|
TTO
|
|
|
-
|
0.453
(0.276-
0.587)
|
0.399
(0.196-
0.550)
|
0.453
(0.275-
0.588)
|
EQ-5D-5L
(cTTO model)
|
|
|
|
-
|
0.969
(0.926-
0.984)
|
0.995
(0.993-
0.996)
|
EQ-5D-5L
(DCE model)
|
|
|
|
|
-
|
0.984
(0.918–
0.993)
|
EQ-5D-5L (Hybrid model)
|
|
|
|
|
|
-
|
EQ-5D-3L Euro-Quality of life five-dimension-three level, EQ-5D-5L Euro-Quality of life five-dimension-five level, VAS visual analog scale, TTO time trade-off, cTTO composite time-trade-off, DCE discrete choice experiment |
*P < 0.001 for all comparison pairs |
As shown in Fig. 2, the Bland-Altman plots for each pair-wise comparison showed wide LOA except for the comparison between each model of the EQ-5D-5L; cTTO model and DCE model (LOA = 0.19), cTTO model and Hybrid model (LOA = 0.10), and DCE model and Hybrid model (LOA = 0.12).
Known group
The mean utility scores of the known-groups by treatment status and presences of symptoms were displayed in Table 5–6. All 6 approaches were able to significantly differentiate treatment status (i.e. treatment, disease free, and progression) as well as presence of symptoms (i.e. no symptoms, 1 symptom, and > 1 symptoms). For treatment status, utility of disease free stage was the highest ranging from 0.829 in EQ-5D-3L to 0.943 in TTO and EQ-5D-5L (DCE model). Utility of treatment stage ranged from 0.637 in TTO to 0.889–0.914 in EQ-5D-5L. On the other hand, utility of progression stage was the lowest ranging from 0.572 in EQ-5D-3L to 0.709–0.772 in EQ-5D-5L. In post hoc analysis, all approaches can differentiate between disease free and progression stage. On the other hand, TTO cannot identify significant difference between treatment and progression stage. All 3 models of EQ-5D-5L cannot differentiate between treatment status and disease free. With regard to presence of symptoms, all 6 approaches were able to significantly differentiate the presence of symptoms (i.e. no symptom, 1 symptom, and > 1 symptoms). In all approaches, patients with > 1 symptoms had significantly lower utility scores than those with no symptom. Also, patients with > 1 symptoms had significantly lower utility scores than those with 1 symptom. It should be noted that all approaches except VAS can differentiate those with no symptom and 1 symptom.
Table 5
Known group validity: Treatment status
Approach
|
Utility: mean (SD)/ median (range)
|
Treatment
(n = 59)
|
Disease free
(n = 97)
|
Progression
(n = 38)
|
P-value*
|
EQ-5D-3La,b,c
|
0.750 (0.219)
/0.726
(0.178-1)
|
0.829 (0.190)
/1.000
(0.116-1)
|
0.572 (0.314)
/0.677
(-0.085-1)
|
< 0.001
|
VASa,b,c
|
0.800 (0.150)
/0.800
(0.500-1)
|
0.851 (0.128)
/0.850
(0.500-1)
|
0.701 (0.173)
/0.725
(0.300-1)
|
< 0.001
|
TTOa,b
|
0.637 (0.350)
/0.800
(0.100–0.950)
|
0.943 (0.066)
/0.950
(0.300–0.950)
|
0.691 (0.304)
/0.925
(0.100–0.950)
|
< 0.001
|
EQ-5D-5L
(cTTO model)b,c
|
0.889 (0.135)
/0.927
(0.518-1)
|
0.924 (0.121)
/0.959
(0.149-1)
|
0.709 (0.268)
/0.793
(0.031–0.959)
|
< 0.001
|
EQ-5D-5L
(DCE model)b,c
|
0.914 (0.098)
/0.952
(0.665-1)
|
0.943 (0.088)
/0.965
(0.385-1)
|
0.772 (0.214)
/0.851
(0.256–0.965)
|
< 0.001
|
EQ-5D-5L (hybrid model)b,c
|
0.889 (0.123)
0.934
(0.577-1)
|
0.927 (0.107)
/0.944
(0.262-1)
|
0.718 (0.245)
/0.808
(0.140–0.944)
|
< 0.001
|
SD standard deviation, EQ-5D-3L Euro-Quality of life five-dimension-three level, EQ-5D-5L Euro-Quality of life five-dimension-five level, VAS visual analog scale, TTO time trade-off, cTTO composite time-trade-off, DCE discrete choice experiment |
* P-value of the Kruskal-Wallis test |
a Mann-Whitney U test: Significant difference between treatment and disease free was identified |
b Mann-Whitney U test: Significant difference between disease free and progression was identified |
c Mann-Whitney U test: Significant difference between treatment and progression was identified |
Table 6
Known group validity: Presence of symptoms
Approach
|
Utility: mean (SD)/ median (range)
|
No symptom
(n = 64)
|
1 symptom
(n = 77)
|
> 1 symptoms
(n = 53)
|
P-value*
|
EQ-5D-3La,b,c
|
0.866 (0.192)/
1 (0.116-1)
|
0.748 (0.192)/
1 (0.116-1)
|
0.630 (0.266)/
0.693 (-0.085-1)
|
< 0.001
|
VAS a,b
|
0.856 (0.124)/
0.825 (0.500-1)
|
0.820 (0.157)/
0.800 (0.300-1)
|
0.725 (0.160)/
0.750 (0.400-1)
|
< 0.001
|
TTO a,b,c
|
0.940 (0.081)/
0.950 (0.300–0.950)
|
0.774 (0.314)/
0.950 (0.100–0.950)
|
0.671 (0.313)/
0.800 (0.100–0.950)
|
< 0.001
|
EQ-5D-5L (cTTO model) a,b,c
|
0.943 (0.132)/
1 (0.149-1)
|
0.871 (0.159)/
0.927(0.261-1)
|
0.785 (0.231)/
0.884 (0.031-1)
|
< 0.001
|
EQ-5D-5L
(DCE model) a,b,c
|
0.956 (0.097)/
1 (0.385-1)
|
0.898 (0.129)/
0.952 (0.334-1)
|
0.838 (0.176)/
0.907 (0.256-1)
|
< 0.001
|
EQ-5D-5L
(hybrid model) a,b,c
|
0.945 (0.116)/
1 (0.262-1)
|
0.870 (0.152)/
0.934 (0.245-1)
|
0.796 (0.207)/
0.875 (0.140-1)
|
< 0.001
|
SD standard deviation, EQ-5D-3L Euro-Quality of life five-dimension-three level, EQ-5D-5L Euro-Quality of life five-dimension-five level, VAS visual analog scale, TTO time trade-off, cTTO composite time-trade-off, DCE discrete choice experiment |
* P-value of the Kruskal-Wallis test |
a Mann-Whitney U test: Significant different between no symptom and > 1 symptoms |
b Mann-Whitney U test: Significant different between 1 symptom and > 1 symptoms |
c Mann-Whitney U test: Significant different between no symptom and 1 symptom |