Development and preliminary validation of Brace Questionnaire (BrQ): A new instrument for measuring quality of life of brace treated scoliotics

Abstract

Background: The quality of life among children with idiopathic scoliosis during their adolescence has been reported to be affected by the brace itself. However, a controversy exists whether brace treated scoliotics experience a poor quality of life, thus there is a need for the development of a brace-oriented instrument, as the now-existing questionnaires that are commonly used, such as the SRS -22, take into consideration the effects of both the conservative and the surgical treatment on quality of life of scoliotic children. The aim of the present study is to assess the validity and reliability of Brace Questionnaire (BrQ), a new instrument for measuring quality of life of scoliotic adolescents who are treated conservatively with a brace. Material-method: Methodology of development involved literature review, patient and health care professionals' in-depth interviews and content validity analysis on patients. A validation study was performed on 28 brace treated scoliotic children aged between 9 and 18 years old. BrQ was assessed for the following psychometric properties: item convergent validity, floor and ceiling effects, internal consistency reliability, clinical validity and responsiveness to change. Results: BrQ is self administrated and developmentally appropriate for ages 9 to 18 years old and is consisted of 34 Likert-scale items associated with eight domains: general health perception, physical functioning, emotional functioning, self esteem and aesthetics, vitality, school activity, bodily pain and social functioning of scoliotic children treated conservatively with a brace. The subscales of these eight dimensions can be combined to produce a total score. Higher scores mean a better quality of life. An item convergent validity ≥ 0.40 was satisfied by all items in the present study. A satisfactory internal consistency reliability for the BrQ was recorded (Cronbach's alpha coefficient was 0.82). There were no floor or ceiling effects. The correlation between BrQ overall scores and mild and moderate scoliosis was statistically significant (p < 0.001), revealing high clinical validity. An increase in effect sizes for the patient with improved scoliotic curves indicates that the BrQ is responsive to change in health status. Conclusion: BrQ is reliable, valid and responsive to change in adolescents with IS who are treated conservatively with a brace. © 2006 Vasiliadis et al; licensee BioMed Central Ltd.