Table 1 Subscale Cronbach’s α and Concordance Correlation Coefficient (CCC) in the study population

Bedtime resistance

0.712 (0.623;0.801)

0.886 (0.823; 0.928)

Sleep onset delay

NA

0.513 (0.319; 0.665)

Sleep duration

0.705 (0.591; 0.819)

0.752 (0.628; 0.839)

Sleep anxiety

0.55 (0.4; 0.7)

0.886 (0.823; 0.928)

Night wakings

0.455 (0.257; 0.653)

0.751 (0.629; 0.837)

Parasomnias

0.487 (0.333; 0.641)

0.846 (0.766; 0.9)

Sleep-disordered breathing

0.697 (0.595; 0.798)

0.859 (0.783; 0.91)

Daytime sleepiness

0.591 (0.46; 0.722)

0.854 (0.774; 0.907)