Table 2

Estimated group means and tests of effects, taken from a multilevel analysis of the primary outcome measures using an intention to treat approach

Estimated group meansTests of effectsCohen’s d between groups
InterventionControlGroupTimeGroup * Time
MeanSE95% CIMeanSE95% CIFP valuedfFP valuedfFP valuePostFollow-up
ISI2.880.09185.396.730.00148.412.570.080.300.39
Baseline10.650.519.64 to 11.6610.740.499.78 to 11.71
Post8.830.547.76 to 9.9010.150.529.12 to 11.19
Follow-up8.830.597.66 to 10.0010.580.549.51 to 11.65
KSQ1.020.31196.1411.250.00153.040.750.47−0.22−0.17
Baseline4.070.103.87 to 4.274.030.103.84 to 4.22
Post4.420.104.22 to 4.624.230.104.04 to 4.43
Follow-up4.340.114.11 to 4.564.200.104.00 to 4.40
SMBQ Global1.450.23190.010.170.84149.744.030.020.360.19
Baseline3.740.123.51 to 3.973.710.113.49 to 3.93
Post3.540.123.30 to 3.773.890.113.67 to 4.12
Follow-up3.660.123.43 to 3.903.840.113.63 to 4.06
SMBQ Fatigue3.900.05187.181.050.35147.173.870.020.450.30
Baseline3.730.133.48 to 3.983.790.123.55 to 4.02
Post3.620.143.35 to 3.884.140.133.89 to 4.40
Follow-up3.640.143.37 to 3.913.960.133.71 to 4.21
SMBQ Cognitive0.100.76189.400.430.65147.133.530.030.240.03
Baseline3.470.153.17 to 3.773.330.143.04 to 3.61
Post3.160.162.85 to 3.473.470.153.18 to 3.77
Follow-up3.370.163.06 to 3.693.370.153.08 to 3.66
WIPL Fatigue0.310.58184.300.440.65149.175.370.010.330.02
Baseline3.430.093.25 to 3.623.320.093.14 to 3.49
Post3.200.102.99 to 3.403.480.103.29 to 3.68
Follow-up3.300.113.08 to 3.513.320.103.13 to 3.52
SSS84.480.04176.3316.300.00132.723.810.030.370.49
Baseline10.820.619.61 to 12.0311.250.5810.11 to 12.39
Post11.730.6910.36 to 13.0913.670.6512.38 to 14.95
Follow-up11.960.7310.51 to 13.4114.690.6813.36 to 16.02
  • Factor labels in tests of effects: Group=Intervention vs Control, Time=Baseline vs Post vs Follow-up, Group*time=interaction term. Df (df) for Time and Group*time are identical.

  • ISI, Insomnia Severity Index, 0–28 severe problems; KSQ, Karolinska Sleep Questionnaire, 1 always— 6 never; Mean, modelled mean values; SMBQ, Shirom-Melamed Burn-out Questionnaire, 1 almost never—7 almost always; SSS8, Somatic Symptom Scale-8, 0–32 very high somatic symptom burden; WIPL, Work Interference with Personal Life, 1 not at all—5 almost all the time.