RESUMO
BACKGROUND: Parents'/caregivers' quality of life is an important aspect to consider when handling paediatric asthma, but there is a paucity of valid and reliable instruments to measure it. The Family Impact of Childhood Bronchial Asthma (IFABI-R) is a recently developed questionnaire to facilitate the assessment of asthma-related parents'/caregivers' quality of life. This study researches the psychometric properties of IFABI-R. METHODS: Parents/main caregivers of 462 children between 4 and 14 years of age with active asthma were included in the sample. IFABI-R was administered on two different occasions and a number of other variables related to the parents'/caregivers' quality of life were measured: child's asthma control, family functioning, and parents'/caregivers' perception of asthma symptoms in the child. IFABI-R evaluative and discriminative properties were analysed, and the minimal important change in the IFABI-R score was identified. RESULTS: IFABI-R showed high internal consistency (Cronbach's alpha=0.941), cross-sectional construct validity (correlation with the degree of child's asthma control, family functioning and parent/caregiver perception of the child's asthma symptoms), longitudinal construct validity (correlation of changes in the IFABI-R with changes in asthma control and changes in the perception of symptoms), sensitivity to change and test-retest reliability. An absolute change of 0.3 units in IFABI-R related to a minimal significant change in the parents'/caregivers' quality of life. CONCLUSIONS: IFABI-R is a reliable and valid instrument to study the quality of life of parents/caregivers of children with asthma.