Reliability and validity of a novel Haemophilia-specific Self-Efficacy Scale

Higher self-efficacy in chronic disease patients is associated with higher development of self-management skills and increased quality-of-life. Quantification and monitoring of self-efficacy is therefore of importance. Self-efficacy in haemophilia patients has received little attention due to lack of standardized scales. To validate the novel Haemophilia-specific Self-Efficacy Scale (HSES) in haemophilia patients on prophylactic home treatment, haemophilia patients aged 1-18years on prophylactic treatment 1year were included from three Dutch Haemophilia Treatment Centres. The HSES consists of 12 items, relating to perceptions of the ability to function on a day-to-day basis with regard to patient's disease. Retest was performed in a subsample. Validity was proven by the General Self-Efficacy Scale and by the health-related quality-of-life assessment tool Haemo-QoL. Data were analysed from 53 children (response 75%), with a mean age of 9.8years (SD 4.0). Mean total scale score of HSES was 55.5 (SD 4.7; range 38-60), with a ceiling effect of 17%. The HSES showed adequate internal consistency (Cronbach's alpha 0.72) and good test-retest reliability (Intra-Class-Correlation coefficient 0.75; P