Ascertainment of the content validity of the Spanish version of the QoLEB entailed translation of the instrument into Spanish followed by its back translation into English, without this showing validity problems. The results of the reliability tests displayed excellent internal consistency and construct validity, α = 0.91. Similarly, internal consistency and construct validity was good-to-excellent for the respective EB subtypes (range α = 0.83–0.93). Overall test-retest reliability was excellent (ps = 0.93), as was reliability in the subtypes (range ps = 0.82–0.93).
The breakdown showed that, of the 33 adults affected by EB who participated in the questionnaire, 22 were women (67%) and 11 were men (33%); 11 persons were diagnosed with EBS (33%), 4 with JEB (13%), 7 with DDEB (21%), and 11 with RDEB (33%); and participants’ mean age was 38 years (range 18–83 years).
The mean time for completing the questionnaire was 5.72 minutes, with no participant taking more than 15 minutes, and the questionnaire response time was considered short.
With respect to the SF-36 questionnaire, in terms of correlation the results obtained indicated that the functional part of the QoLEB was well correlated with the SF-36 PCS (physical component summary) (ps = 0.70), and the emotional QoLEB was moderately correlated with the SF-36 MCS (ps = 0.49).
Assessment of the QoLEB
A confirmatory factor model was used to validate the QoLEB questionnaire in Spanish. Our analysis confirmed that the questionnaire significantly separated items pertaining to functional and emotional elements.
From these results, it could be seen that the functional and emotional variables were correlated (covariance 0.67) and that items had significant factor loadings with coefficients of 0.44 to 0.72 (see Fig. 1). In addition, the results showed that there were no floor or ceiling effects, since the proportion of maximum or minimum scores in each of the questions did not exceed 70% of subjects surveyed.
Table I shows the results of the Spanish version of the QoLEB, with a breakdown by sex cohort and EB subtype. Women had a lower health-related quality of life than did men, though these differences did not reach statistical significance. There was a statistically significant exception in the emotional section of the Spanish QoLEB (p = 0.007).
Table I. Results of the Spanish version of the Quality of Life in Epidermolysis Bullosa (QoLEB) questionnaire by sex and EB subtype

In general terms, the EBS and DDEB subtypes displayed a better health-related quality of life on most of the scales than did the RDEB and JEB groups. These differences attained discriminant validity for the functional scale (p = 0.003) and global score (p = 0.033), but not for the emotional scale. Among the different groups, there were significant differences in the functional section between the EBS-RDEB (p = 0.008) and DDEB-RDEB groups (p = 0.020), and also in total scores between the EBS and RDEB groups (p = 0.085).
Table II shows the level of the impact on participants’ quality of life, by the type of disease affecting them: 35% of interviewees reported a severe-to-very severe impact on their quality of life, as opposed to 26% who reported experiencing a slight-to-very slight impact; the remaining 39% reported a moderate impact. Similarities were observed with regard to the scores registered for the EBS and DDEB subtypes, and some slight differences with respect to JEB and RDEB.
Table II. Impact on quality of life by EB subtype, according to the results obtained from Spanish version of the QoLEB questionnaire
|
EBS
|
JEB
|
DDEB
|
RDEB
|
Total
|
Very slight (0–4 points)
|
1 (9%)
|
0
|
2 (29%)
|
0
|
3 (8%)
|
Slight (5–9 points)
|
4 (36%)
|
0
|
1 (13%)
|
1 (9%)
|
6 (18%)
|
Moderate (10–19 points)
|
4 (36%)
|
2 (50%)
|
2 (29%)
|
5 (46%)
|
13 (39%)
|
Severe (20–34 points)
|
2 (19%)
|
2 (50%)
|
2 (29%)
|
4 (36%)
|
10 (33%)
|
Very severe (35–51 points)
|
0
|
0
|
0
|
1 (9%)
|
1 (2%)
|
Total =
|
11 (100%)
|
4 (100%)
|
7 (100%)
|
11(100%)
|
33(100%)
|
The results of the 17 individual QoLEB questions are listed in Table III.
While 100% of patients interviewed experienced pain, 18% of these reported experiencing constant pain; in terms of relationships with family and friends, EB affected 42% of participants, though in most of these cases it affected them slightly; 51% had some difficulty in eating, and the same percentage needed some type of aid for bathing or showering; and 39% experienced some limitation in writing, with this limitation being especially important in those affected by RDEB, among whom 27% were unable to write. All persons interviewed reported some limitation when it came to engaging in sports, with 81% having to avoid all or some sports; 61% reported experiencing limitations in the home, though these were slight in the great majority of cases; this percentage rose to 70% when movements took place outside the house, where scores were observed to rise with respect to those obtained in the question that analysed how EB affected movements within and around the home. Practically the same percentage was obtained, specifically 72%, when it came to shopping, and this same figure was obtained in response to the question about how EB affected the family’s financial status. EB caused 82% of the patients interviewed to feel frustrated, 51% to feel embarrassed, 76% to feel worried or anxious, 57% to feel depressed, and 63% to feel uneasy.
Table III. Results of the 17 Spanish QoLEB questions, by EB subtype
|
Points
|
EBS
n = 11
n(%)
|
JEB
n = 4
n(%)
|
DDEB
n = 7
n(%)
|
RDEB
n = 11
n(%)
|
Total
n = 33
n(%)
|
1. Move around the house
|
0
1
2
3
|
5 (45)
6 (55)
|
4 (100)
|
5 (71)
2 (29)
|
3 (27)
7 (64)
1 (9)
|
13 (39)
19 (58)
1 (3)
|
2. Bath/shower
|
0
1
2
3
|
9 (82)
2 (18)
|
3 (75)
1 (25)
|
4 (57)
3 (43)
|
3 (27)
2 (18)
1 (9)
5 (46)
|
16 (48)
10 (30)
1 (3)
6 (18)
|
3. Pain
|
0
1
2
3
|
8 (73)
3 (27)
|
1 (25)
3 (75)
|
3 (43)
1 (14)
3 (43)
|
5 (46)
3 (27)
3 (27)
|
17 (51)
10 (30)
6 (18)
|
4. Write
|
0
1
2
3
|
9 (82)
2 (18)
|
2 (50)
2 (50)
|
5 (71)
2 (29)
|
4 (36)
4 (36)
3 (27)
|
20 (61)
4 (12)
6 (18)
3 (9)
|
5. Eat
|
0
1
2
3
|
10 (91)
1 (9)
|
4 (100)
|
5 (71)
2 (29)
|
1 (9)
2 (18)
5 (46)
3 (27)
|
16 (48)
7 (21)
7 (21)
3 (9)
|
6. Shopping
|
0
1
2
3
|
2 (18)
7 (64)
2 (18)
|
1 (25)
2 (50)
1 (25)
|
4 (57)
2 (29)
1 (14)
|
3 (27)
3 (27)
2 (18)
3 (27)
|
9 (27)
13 (39)
7 (21)
4 (12)
|
7. Sports
|
0
1
2
3
|
1 (9)
9 (82)
1 (9)
|
1 (25)
3 (75)
|
3 (43)
3 (43)
1(14)
|
2 (18)
3 (27)
6 (55)
|
6 (18)
16 (48)
11 (33)
|
8. Frustration
|
0
1
2
3
|
1 (9)
7 (64)
3 (27)
|
3 (75)
1 (25)
|
2 (29)
3 (43)
2 (29)
|
3 (27)
5 (45)
3 (27)
|
6 (18)
18 (55)
8 (24)
1 (3)
|
9. Move outside house
|
0
1
2
3
|
4 (36)
3 (27)
4 (36)
|
3 (75)
1 (25)
|
4 (57)
3 (43)
|
2 (18)
5 (45)
3 (27)
1 (9)
|
10 (30)
14 (42)
8 (24)
1 (3)
|
10. Family
|
0
1
2
3
|
7 (64)
4 (36)
|
2 (50)
1 (25)
1 (25)
|
5 (71)
2 (29)
|
5 (45)
3 (27)
3 (27)
|
19 (58)
10 (30)
4 (12)
|
11. Embarrassment
|
0
1
2
3
|
7 (64)
3 (27)
1 (9)
|
2 (50)
1 (25)
1 (25)
|
3 (43)
1 (14)
2 (29)
1 (14)
|
4 (36)
7 (64)
|
16 (48)
11 (33)
4 (12)
2 (6)
|
12.Home modifications
|
0
1
2
3
|
9 (82)
2 (18)
|
2 (50)
2 (50)
|
7 (100)
|
3 (27)
6 (55)
2 (18)
|
21 (64)
10 (30)
2 (6)
|
13. Friends
|
0
1
2
3
|
8 (73)
1 (9)
2 (18)
|
2 (50)
2 (50)
|
4 (57)
3 (43)
|
5 (45)
5 (45)
1 (9)
|
19 (58)
9 (27)
5 (15)
|
14. Anxiety
|
0
1
2
3
|
3 (27)
6 (55)
2 (18)
|
3 (75)
1 (25)
|
2 (29)
4 (57)
1 (14)
|
3 (27)
6 (55)
1 (9)
1 (9)
|
8 (24)
19 (58)
5 (15)
1 (3)
|
15. Financial
|
0
1
2
3
|
5 (45)
6 (55)
|
1 (25)
3 (75)
|
3 (43)
3(43)
1 (14)
|
1 (9)
5 (45)
5 (45)
|
9 (27)
15 (45)
9 (27)
|
16. Depression
|
0
1
2
3
|
4 (36)
7 (64)
|
3 (75)
1 (25)
|
3 (43)
3 (43)
1 (14)
|
7 (64)
3 (27)
1 (9)
|
14 (42)
16 (48)
2 (6)
1 (3)
|
17. Intimidation
|
0
1
2
3
|
5 (45)
4 (46)
1 (9)
1 (9)
|
1 (25)
1 (25)
2 (50)
|
2 (29)
2 (29)
3 (43)
|
4 (36)
4 (36)
3 (27)
|
12 (36)
11 (33)
9 (27)
1 (3)
|
Short Form-36 results
EB had a greater impact on health-related quality of life among women than among men, but the differences did not prove significant (Table IV).
Table IV. SF 36 questionnaire values, by sex and EB subtype
|
n
|
PF*
Mean/SD
|
RP*
Mean/SD
|
BP*
Mean/SD
|
GH*
Mean/SD
|
VT*
Mean/SD
|
SF*
Mean/SD
|
RE*
Mean/SD
|
MH*
Mean/SD
|
PCS*
Mean/SD
|
MCS*
Mean/SD
|
Total
|
31
|
38.0 ± 10.4
|
40.2 ± 8.0
|
38.5 ± 8.9
|
37.9 ± 12.7
|
40.3 ± 10.2
|
37.6 ± 13.1
|
42.5 ± 8.7
|
44.7 ± 10.5
|
36.6 ± 11.1
|
44.7 ± 10.9
|
Men
|
9
|
41.3 ± 11.8
|
42.3 ± 7.4
|
42.8 ± 7.0
|
37.3 ± 12.3
|
43.0 ± 9.3
|
41.8 ± 13.4
|
44.3 ± 8.3
|
46.4 ± 10.3
|
39.3 ± 10.8
|
46.5 ± 11.0
|
Women
|
22
|
36.7 ± 9.8
|
39.4 ± 8.2
|
36.7 ± 9.1
|
38.2 ± 13.1
|
39.8 ± 10.6
|
35.9 ± 12.9
|
41.8 ± 9.0
|
44.0 ± 10.8
|
35.4 ± 11.3
|
44.0 ± 11.0
|
EB subtype
|
|
|
|
|
|
|
|
|
|
|
|
EBS
|
11
|
45.6 ± 8.2
|
44.9 ± 8.2
|
42.9 ± 5.7
|
46.2 ± 12.3
|
45.4 ± 7.6
|
44.9 ± 8.9
|
44.0 ± 6.9
|
46.8 ± 10.3
|
44.8 ± 9.0
|
45.7 ± 11.8
|
JEB
|
4
|
29.8 ± 6.9
|
34.8 ± 7.0
|
36.7 ± 10.5
|
37.8 ± 11.6
|
39.5 ± 6.9
|
28.4 ± 10.7
|
36.5 ± 8.0
|
42.7 ± 10.2
|
32.3 ± 12.3
|
41.1 ± 9.1
|
DDEB
|
6
|
36.9 ± 8.6
|
38.8 ± 7.4
|
34.1 ± 11.0
|
35.9 ± 13.1
|
33.8 ± 14.6
|
37.3 ± 14.5
|
42.7 ± 13.2
|
40.5 ± 13.5
|
34.3 ± 10.1
|
42.1 ± 15.5
|
RDEB
|
10
|
33.6 ± 10.4
|
38.1 ± 6.6
|
37.0 ± 9.2
|
30.0 ± 8.6
|
39.0 ± 9.4
|
34.4 ± 15.0
|
43.3 ± 7.9
|
45.9 ± 9.7
|
30.6 ± 9.2
|
46.6 ± 9.0
|
* |
PF: physical function; RP: role physical; BP: bodily pain; GH: general health; VT: vitality; SF: social function; RE: role emotional; MH: mental health; PCS: physical component summary; MSC: mental component summary |
Significant differences were found in the following domains: physical function (p = 0.010); role physical (p = 0.079); and general health (0.024). Comparing these between subgroups, statistical significance was achieved on the physical function scale between the EBS-JEB (p = 0.026) and EBS-RDEB groups (p = 0.024); and statistically significant differences were also found on the general health scale between the EBS and RDEB groups (p = 0.014).
As mentioned above, the results obtained for the functional part of the Spanish version of the QoLEB and the physical component summary of the SF-36 displayed a good correlation (ps = 0.701). The correlation between the results obtained for the emotional questions of the Spanish version of the QoLEB and the mental component summary of the SF-36 questionnaire were moderately correlated (ps = 0.4919)