Quality of life evaluation in epidermolysis bullosa (EB) through the development of the QOLEB questionnaire: an EB-specific quality of life instrument.

BACKGROUND

Epidermolysis bullosa (EB) has a profound effect on quality of life (QOL); however, generic QOL assessments are poor indicators of the impact of EB.

OBJECTIVES

To develop a valid and reliable EB-specific QOL tool for use in measuring the effects of disease impact and interventions.

METHODS

Open, nonstructured interviews were conducted with 26 patients with EB, along with 33 family members and 11 health professionals (70 individuals) for item generation. A pilot questionnaire was compiled, refined and distributed to 130 patients with EB. From the 115 returned questionnaires a principal axis factor analysis was undertaken producing a 17-item final questionnaire. Discriminative validity was assessed by differences in scores between EB subtypes. Content validity was assessed by expert ranking of items in terms of importance. Construct validity was evaluated by correlation with existing QOL tools. Test-retest reliability and internal consistency were evaluated. Factor analysis was performed.

RESULTS

A 17-item questionnaire was developed: the QOLEB questionnaire. This gave distinguishing QOL scores to different EB subtypes, and correlated highly with existing QOL instruments.

CONCLUSIONS

The QOLEB questionnaire is the first EB-specific QOL measurement tool, and is a valid and reliable measurement tool for the quantification of QOL in patients with various subtypes of EB. In addition, the QOLEB has potential as a sensitive instrument to monitor QOL, and to identify dimensions of QOL as targets for interventions and research.