Table 4

Adjusted multinomial logistic regression models for the associations between persistent pain status at 18 months and wage replacement duration group, overall cohort (n=1131)

Wage replacement duration 3–12 months vsWage replacement duration 12–18 months vs
1 day to 3 months1 day to 3 months
Model 1Model 2Model 1Model 2
OR95% CIP valueOR95% CIP valueOR95% CIP valueOR95% CIP value
Model intercept0.700.441.120.140.760.471.210.25 0.24 0.14 0.41 <0.01 0.25 0.15 0.44 <0.01
Pain groupMild pain, functional impairment unlikely1.290.901.850.171.300.901.870.16 2.93 1.90 4.52 <0.01 3.09 1.99 4.81 <0.01
Ref: no pain groupSevere pain, functional impairment likely 2.00 1.33 3.02 <0.01 2.04 1.34 3.10 <0.01 8.46 5.35 13.38 <0.01 9.35 5.85 14.94 <0.01
Claimant age<30 years old0.630.371.090.100.630.361.090.100.790.451.410.430.790.441.420.43
Ref: 30–39 years old40–49 years old0.950.581.550.850.950.581.550.831.100.661.840.721.130.671.910.65
50–59 years old1.200.771.880.411.230.781.930.371.330.832.140.231.350.832.190.23
Over 60 years old1.200.712.010.491.140.671.940.62 1.77 1.04 3.01 0.03 1.75 1.02 3.01 0.04
SexFemale0.840.621.140.260.830.611.130.230.820.601.120.200.850.621.170.32
Ref: male and other not specified
Nature of injuryFracture 2.72 1.61 4.61 <0.01 2.74 1.61 4.65 <0.01 2.96 1.72 5.10 <0.01 2.98 1.72 5.16 <0.01
Ref: sprain/strain/dislocationSuperficial or open wound 0.50 0.30 0.84 0.01 0.50 0.30 0.83 0.01 0.700.431.130.150.710.441.160.17
Organ/blood vessel/muscle injury, internal injury, crushing, amputation1.330.832.150.241.360.842.200.21 1.56 0.96 2.53 0.07 1.57 0.97 2.56 0.07
Other 3.64 1.70 7.79 <0.01 3.71 1.73 7.95 <0.01 0.520.151.740.290.530.161.780.30
Unknown1.470.872.470.151.460.852.500.17 2.29 1.37 3.80 <0.01 2.30 1.36 3.90 <0.01
Prior chronic conditionBack problems prior to the work injury--------0.860.571.300.47-------- 0.65 0.42 1.00 0.05
Ref: no prior conditionArthritis prior to the work injury--------0.950.621.470.82--------1.040.681.610.84
Mood disorder prior to the work injury-------- 0.64 0.40 1.03 0.07 -------- 0.45 0.27 0.76 <0.01
  • Model 1 independent variables: pain group, claimant age, sex and nature of injury. Model 2 independent variables: Model 1+ presence of back problems prior to the work injury, presence of arthritis prior to the work injury and presence of a mood disorder prior to the work injury. Bold values indicate OR statistically significant at the α=0.05 level.