Application of the Sleep Disturbance Scale for Children (SDSC) in infants and toddlers (6-36 months)

Objectives: The aim of the present study is to assess the psychometric properties of the Sleep Disturbance Scale for Children (SDSC) in an Italian population of infants and toddlers.

Methods: The SDSC was distributed to the primary caregivers of infants aged 6-36 months recruited via nurseries in the urban area of Rome. Reliability analysis for evaluating internal consistency and item-total correlation coefficients, and factor analysis were performed.

Results: During a 12-months study period, a total of 193 healthy infants (aged 6-36 months) were evaluated using a 22-item version of the SDSC for Italian infants and toddlers. Three of the 22 original items displayed a low item-total correlation (<30) and a low frequency and were eventually removed, resulting in a 19 items questionnaire. Six factors were derived from the factor analysis using the principal component method of extraction and rotated with the varimax method: Difficulty in initiating sleep, Difficulty in maintaining sleep, Sleep breathing disorders, Parasomnias, Disorders of excessive somnolence and Sleep hyperhidrosis. The SDSC adapted for infants and toddlers showed a good level of internal consistency (Cronbach's alpha: 0.83).

Conclusions: The statistical analysis, the internal consistency and the factor analysis encourage the use of SDSC as an evaluation tool even at this age. The six factors extracted represent the most common areas of sleep disorders at this age and could therefore help clinicians to detect the areas that need a deeper investigation.