Table 2.
Means and SDs of the internet-based cognitive behavioral therapy for insomnia (iCBT-I) intervention group and the active control group (aCG) at T1, T2, and T3 for the intention-to-treat sample (N=90).
| Outcome | T1a, mean (SD) | T2b, mean (SD) | T3c, mean (SD) | ||||||||||||
|
|
iCBT-Id | aCG | iCBT-I | aCG | iCBT-I | aCG | |||||||||
| Primary outcome | |||||||||||||||
|
|
Insomnia severitye | 16.51 (36.5) | 16.29 (3.09) | 11.27 (5.21) | 12.36 (4.16) | 9.43 (5.36) | 12.44 (5.39) | ||||||||
| Secondary outcomes | |||||||||||||||
|
|
Sleep quality (PSQIf)g | 1.00 (0.48) | 1.04 (0.52) | 1.52 (0.72) | 1.40 (0.49) | 2.24 (0.66) | 2.36 (0.57) | ||||||||
|
|
Sleep efficiency (PSQI)h | 73.10 (15.28) | 75.04 (12.94) | 81.80 (14.34) | 78.34 (11.96) | 83.86 (11.07) | 80.51 (12.87) | ||||||||
|
|
Cognitive irritation (ISi)j | 13.47 (4.77) | 12.33 (5.24) | 12.39 (5.08) | 11.01 (5.23) | 11.53 (5.51) | 11.88 (5.51) | ||||||||
|
|
Worrying (PSWQk)l | 9.04 (3.92) | 9.51 (4.16) | 7.95 (3.97) | 8.20 (3.71) | 7.82 (4.28) | 8.05 (4.20) | ||||||||
|
|
Recovery experiences (REQm)n | 48.31 (6.90) | 49.93 (8.12) | 49.32 (9.03) | 50.89 (8.29) | 52.04 (10.05) | 52.73 (9.48) | ||||||||
|
|
REQ_psychological detachment | 10.62 (3.26) | 11.71 (3.31) | 11.29 (3.45) | 11.97 (3.47) | 12.61 (3.86) | 12.45 (4.08) | ||||||||
|
|
REQ_relaxation | 12.71 (2.71) | 12.18 (2.83) | 13.01 (2.84) | 13.16 (2.71) | 13.18 (3.40) | 13.22 (3.60) | ||||||||
|
|
REQ_mastery | 10.31 (2.20) | 11.20 (3.75) | 10.92 (3.66) | 10.80 (3.95) | 10.98 (3.46) | 11.96 (3.49) | ||||||||
|
|
REQ_control | 14.67 (3.03) | 14.84 (2.66) | 14.18 (3.35) | 14.95 (2.44) | 15.38 (3.65) | 15.06 (2.60) | ||||||||
|
|
Recovery activities (ReaQo)p | 30.02 (10.06) | 28.11 (10.06) | 30.52 (11.55) | 32.19 (12.30) | 31.18 (9.53) | 29.26 (11.11) | ||||||||
|
|
Recuperation in sleep (SFBq)r | 17.82 (4.91) | 17.73 (4.17) | 20.51 (6.01) | 19.29 (5.67) | 21.63 (6.24) | 19.82 (5.02) | ||||||||
|
|
Presenteeism (PSSs Subscale WISt)u | 46.22 (15.70) | 48.78 (13.33) | 42.77 (16.05) | 43.40 (14.46) | 46.30 (18.95) | 43.52 (13.64) | ||||||||
|
|
Procrastination (PFSv)w | 21.58 (8.13) | 21.13 (7.07) | 19.37 (7.36) | 20.61 (6.88) | 21.00 (8.58) | 21.09 (6.75) | ||||||||
aT1=baseline before randomization.
bT2=8-week posttreatment.
cT3=6-month follow-up.
dIntervention group.
eInsomnia Severity Index (0-28), with higher scores reflecting higher insomnia symptoms.
fPSQI: Pittsburgh Sleep Quality Index.
gSleep quality (0-3), with lower scores reflecting better sleep quality.
hSleep efficiency (0-100), with higher scores indicating increased sleep efficiency.
iIS: Irritation Scale.
jIrritation Scale (3-21), with higher scores indicating heightened hyperarousal.
kPenn State Worry Questionnaire.
lPenn State Worry Questionnaire (0-18), with higher scores reflecting stronger worrying.
mREQ: Recovery Experience Questionnaire.
nRecovery Experience Questionnaire (16-80), with higher scores reflecting better recovery experiences, subscales psychological, detachment, relaxation, mastery, control (4-20) with higher scores reflecting better recovery experiences.
oReaQ: Recreation Experience and Activity Questionnaire.
pRecreation Experience and Activity Questionnaire (21-105), with higher scores indicating increased engagement in recovery activities.
qGerman sleep questionnaire.
rGerman sleep questionnaire (8-40), with higher items reflecting higher recuperation in sleep.
sPSS: Presenteeism Scale for Students.
tWIS: Work improvement score.
uPresenteeism scale for students, work impairment score (20-100), with higher scores reflecting a lower level of presenteeism.
vPFS: Procrastination scale for students.
wProcrastination scale for students (7-35), with higher scores indicating higher procrastination behavior.