[Adaptation and study of the measurement properties of a sleep questionnaire for infants and pre-school children].

Introduction: Although sleep disturbances in infants and toddlers are common, there is no suitable validated tool in Spanish to evaluate sleep disorders. The Brief Infant Sleep Questionnaire (BISQ) is a well-established multidimensional questionnaire widely used internationally.

Objectives: To adapt the BISQ questionnaire to Spanish and analyse its reliability and validity. To explore its feasibility, both in the clinical context, and in epidemiological research.

Methods: Participants were parents of children between 3 and 30 months of age. The adaptation to Spanish (BISQ-E) was achieved by using both back translation and consensus, following the international guidelines.Reliability was determined by means of test-retest and measurement of agreement (Kappa value) between 2forms of administration of the questionnaire (self-administration and clinical interview). Construct validity was established by analysing its correlation with a sleep diary.

Results: A total of 87 families/children participated. The test-retest reliability undertaken in 60 subjects was excellent; r = 0.848 (P<0.001). The kappa value was 0.939 (95% CI: 0.858-1.00, P<0.001).The agreement between BISQ-E and the sleep diary was analysed in 27 families/children, with statistically significant values being obtained for the following variables: bedtime (r = 0.731), hours of night sleep (r = 0.726), hours of daytime sleep (r = 0.867), and number of nocturnal awakenings (r = 0.888) (P < 0.001).

Conclusions: The Spanish adaptation of the BISQ shows overall adequate validity and reliability for the evaluation of sleep in infants and pre-school children. Its use as a clinical tool, or for clinical-epidemiological research studies, is feasible.