Poster Presentation ASPCR-ASDR Conference 2013

Excellent reliability and validity of a novel Epidermolysis Bullosa Disease Activity and Scarring Index (EBDASI) compared to two other outcome measures (#105)

Clement CH Loh 1 2 , Jaehwan Kim 2 , John Su 3 , Benjamin S Daniel 4 , Supriya S Venugopal 5 , Lesley Rhodes 2 , Lizbeth RA Intong 2 , Matthew Law 6 , Dedee F Murrell 2
  1. Faculty of Medicine , University of New South Wales, Sydney, Australia
  2. St George Hospital, Sydney, NSW, Australia
  3. Department of Paediatrics, University of Melbourne, Melbourne, Australia
  4. Department of Medicine, St Vincent's Hospital, Sydney, Australia
  5. Deparment of Dermatology, Westmead Hospital, Sydney, Australia
  6. The Kirby Institute, University of New South Wales, Sydney, Australia

Introduction

There is a lack of validated outcome measures for epidermolysis bullosa (EB) which measure disease activity separately from damage. We present a novel EB Disease Activity and Scarring Index (EBDASI), which scores activity responsive to therapy separately from scarring, which we have validated.

 Method

Content validity was established by including all physical complications of EB and adapting the scoring methodology from another validated blistering disease severity score, the Pemphigus Disease Area Index, to create the EBDASI. We compared the reliability and validity of the EBDASI against the Birmingham EB Scale (BEBS), using the Physician’s Global Assessment Scale (PGA) as a reference measurement.  Sixteen patients of different EB subtypes and severities   were scored separately by five EB experts using the EBDASI, BEBS and PGA on the same day.

 Results

For inter-rater assessment, the intra-class correlation coefficients (ICCs) for overall total score were:  EBDASI 0.964, BEBS 0.852, and PGA 0.873. For intra-rater reliability, the ICCs (95% C.I) were: EBDASI 0.994(0.976-0.998), BEBS 0.926(0.748–0.981), and PGA 0.932(0.764–0.982).  The EBDASI correlated better with PGA (ρ= 0.871) than the BEBS with PGA (ρ= 0.852). Scatter-plots showed that EBDASI had better correlations with increased severity scores than BEBS. 9 other EB patients were also assessed with ad-hoc scores ranging from 85–212/506(RDEB) and 94-113/506(JEB).

 Conclusion

 The EBDASI demonstrated excellent reliability and validity, which is superior to BEBS.