Table 4 Differential item functioning by age ^a of the MISS and MISS-R

…difficulties falling asleep (1)

2.958

0.0861

0.738

0.619

…night awakening (2)

3.325

0.0689

0.271

0.950

…not being rested by sleep (3)

15.703

< 0.001 ^c

−0.132

0.999

…difficulties falling asleep (1)

0.495

0.482

0.798

0.450

…night awakening (2)

0.293

0.588

1.756

0.173

…not being rested by sleep (3, younger)

–

–

–

–

…not being rested by sleep (3, older)

–

–

–

–

…difficulties falling asleep (1)

3.640

0.0570

0.926

0.476

…night awakening (2)

3.516

0.0614

0.482

0.822

…daytime disturbance (4)

18.731

< 0.001^c

0.380

0.892

…difficulties falling asleep (1)

0.072

0.789

−0.023

0.999

…night awakening (2)

0.031

0.860

0.031

0.970

…daytime disturbance (4, younger)

–

–

–

–

…daytime disturbance (4, older)

–

–

–

–