Table 3 Baseline characteristics and sickness absence in the intervention and control (usual care) groups in RCT 1 (occupational health intervention for the high risk group) and RCT 2 (telephone advice for the intermediate risk group)
Group allocation
Intermediate risk (IR)High risk (HR)
Control (IR-CG)Intervention (IR-IG)Control (HR-CG)Intervention (HR-IG)
Mean age (years)42.942.846.846.7
Sex (female; %)121366
Blue-collar (%)57588077
Sickness absence
    None (% within group)60554334
    Mean (days)4.65.917.919.7
    Standard deviation9.511.536.337.0
    Median (days)0146
    Upper quartile (days)561820
    Maximum (days)7270229221
    Sum (days)1246158137364115
Employment terminated during follow-up (%)
1 year follow-up
Sickness absence
    None (% within group)46452331
    Mean (days)
    Standard deviation14.312.453.344.0
    Median (days)1295
    Upper quartile (days)773215
    Maximum (days)11573286365
    Sum (days)1755175157443702