Hindi translation and validation of quality of life score in Indian patients with epidermolysis bullosa; and its correlation with the clinical severity assessment scores: A cross-sectional study
Authors: Bishnoi Anuradha , Manjunath Seema , Kishore Kamal , De Dipankar , Handa Sanjeev , Murrell Dedee F , Mahajan Rahul 
Published: August 2021

Background:
Quality of life (QoL) has not been evaluated in Indian patients having epidermolysis bullosa (EB).

Aims:
The aims of the study were to measure health-related QoL in Indian patients having EB using the quality of life in epidermolysis bullosa (QoLEB) questionnaire, and to find its correlation with clinically measured disease severity.

Methods:
In this observational cross-sectional study, the QoLEB questionnaire was translated from English to Hindi (QoLEB-Hin) and culturally adapted without a change in concept following standard guidelines. QoLEB-Hin and three clinical scores that have been independently validated in EB, that is, Birmingham Epidermolysis Bullosa severity score (BEBs), Instrument for Scoring Clinical Outcomes of Research for Epidermolysis Bullosa (iscorEB) and Epidermolysis Bullosa Disease Activity and Scarring Index (EBDASI), were administered to EB patients/their parents in the presence of an expert. This was followed by validity and correlation studies.

Results:
Fifty-four patients were recruited (19-females, 35-males; median age 5 years, range 0.025–36 years and 12 patients with an age >13 years). The parents answered the questions for 42 patients (age <13 years). Dystrophic epidermolysis bullosa was diagnosed in 32 (59.2%) patients (dominant dystrophic epidermolysis bullosa [DDEB]-19 [35.2%] and recessive dystrophic epidermolysis bullosa [RDEB]-13 [24.1%]). Junctional epidermolysis bullosa (JEB) and epidermolysis bullosa simplex (EBS) were each diagnosed in 11 (20.4%) patients. The mean ± standard deviation (SD) of QoLEB-Hin score of all epidermolysis bullosa patients was 11.3 ± 7.6 (range 0–28; median and interquartile range [IQR], 10, 10) and reflected an overall moderate degree of affliction on QoL of patients. Mean ± SD of QoLEB-Hin scores for EBS, JEB, DDEB and RDEB were 5.4 ± 3.7 (range, 1–13; median and IQR, 6, 6), 11 ± 6.2 (range, 1–22; median and IQR, 10, 6), 9 ± 5.7 (range, 0–19; median and IQR, 10, 10) and 20.1 ± 6.4 (range, 12–28; median and IQR, 19, 12.5), respectively (P < 0.001, Kruskal–Wallis analysis of variance). Cronbach’s alpha coefficient of 0.946 was obtained for all items indicating excellent internal consistency and reliability. Mean sample adequacy was 0.91; absolute fit based off diagonal values was 0.99; indices root mean square error of approximation and root mean square residual were 0.04 and 0.05, respectively, and Tucker Lewis index was >1 indicating overfit. The mean time taken to complete the questionnaire was 6.1 min (range, 6–8 min). QoLEB-Hin correlated significantly (P < 0.001) with BEBs (ρ = 0.79), iscorEB (ρ= 0.63) and EBDASI (ρ = 0.77). Three multiple linear regression models were used to ascertain the strength of relationship between QoL-Hin, and BEBs, iSCOREB and EBDASI, respectively, after adjusting for age, gender and disease subtype. The EBDASI clinical score accounted for approximately 74% (R2 = 0.736, P < 0.001) of the variability in QOL-Hin, as compared to 73% and 55% by BEBs (R2 = 0.731, P < 0.001) and iscorEB (R2 = 0.545, P < 0.001), respectively.

Limitations:
Parents filled out the questionnaires for many patients and probably led to an overall moderate degree of affliction of QoL. Comparison with Dermatology Life Quality Index and other QoL scores were not done in this study. Furthermore, the scoring was done at one point in time, and test-retest measurements could not be performed.

Conclusion:
This study validated QoLEB-Hin in an Indian population finding an overall moderate reduction in QoL due to EB. Maximally affected QoL was seen in patients with RDEB. Furthermore, QoLEB-Hin had a variable positive correlation and association with all clinical severity assessment scores.