2.2. Subjects and Randomization
Depression, insomnia, sleep disturbance
RECRUITMENT
Subjects with insomnia symptoms were recruited using recruitment posters through universities and social network agencies from July 2021 to February 2022. Subjects were considered eligible if they: (1) were Chinese Hong Kong residents who could read Chinese; (2) were aged 18–65 years; (3) reported subjective sleep complaints relating to difficulties falling asleep, difficulties staying asleep, or early morning awakening with consequences for daily life for at least three months; (4) demonstrated Pittsburgh Sleep Quality Index (a) total scores of at least 5, indicating sleep disturbance with 89.6% sensitivity and 86.5% specificity (b); and (5) were willing to give informed consent and comply with the trial protocol.Subjects were excluded if they: (1) were receiving psychotherapy or participating in other clinical trials for insomnia; (2) were pregnant; (3) were shift workers; (4) were at significant risk of suicide as rated by the Hamilton Depression Rating Scale item on suicide (score ≥ 3) [A computer-generated randomization list with a random block size of four to six was prepared by an independent researcher. After the completion of baseline assessment, the independent researcher gave the group allocation to a staff member responsible for keeping the pajamas and delivering them to the subjects. All the assessments in this study were self-completed. The researchers who performed the assessment and analysis were blinded to the group allocation. All the subjects were blinded to their group allocation.