Table 2

Factors at baseline that predicted intense LBP during the successive three months

Characteristics at baselineOdds ratio (95% CI)
The final equation in a forward stepwise logistic regression analysis, with likelihood ratio test was used as the criterion for determining variables to be removed from the model. n = 2982.
The overall rate of correct classification of the dependent variable (predicted outcome compared with the observed outcome) was estimated as 86.18%.
The factors not retained in the final equation were age, gender, number of years the subject had been working as a nurses’ aide, level of affective symptoms, sleep complaints, long term health problems of any kind, having (ever) changed work or work tasks because of pain, working in a nursing home, the extent to which the work required physical endurance, frequency of lifting and supporting patients manually between bed and chair, frequency of handling heavy objects at work, quantitative work demands, level of influence on decisions at work, level of control over work pace, level of role conflicts at work, fairness of the immediate superior’s leadership, the extent of supportive and encouraging culture in the work unit, rewards for good work, exposure to bullying at work, and level of commitment to the work unit.
Positioning patients in the bed (per average shift)
    1–41.27 (0.91 to 1.78)
    5–91.63 (1.14 to 2.31)
    ⩾101.26 (0.83 to 1.91)
Support from immediate superior
    1 (lowest quintile)1.00
    20.60 (0.44 to 0.83)
    30.59 (0.39 to 0.87)
    40.71 (0.49 to 1.02)
    50.75 (0.52 to 1.09)
Relaxing and pleasant culture in the work unit
    Not at all/very little1.00
    Rather little0.46 (0.24 to 0.89)
    Some0.54 (0.31 to 0.96)
    Rather much0.65 (0.37 to 1.15)
    Very much0.79 (0.43 to 1.45)
Number of preschool children
    11.64 (1.16 to 2.31)
    ⩾21.02 (0.58 to 1.79)
Special tasks of caring nature in the leisure time (e.g. caring for elderly relatives or handicapped children)
    A little0.82 (0.62 to 1.09)
    Rather much or very much1.58 (1.03 to 2.42)
LBP previous 3 months
    Yes3.39 (2.61 to 4.40)
Widespread pain
    Yes1.67 (1.30 to 2.14)
Intensity of musculoskeletal pain (any)
    A little2.45 (1.29 to 4.65)
    Rather intense3.75 (1.95 to 7.21)
    Very intense3.49 (1.72 to 7.03)
    Always or usually fit1.00
    Varied between fit and fatigued1.49 (1.14 to 1.96)
    Usually or always fatigued1.58 (1.09 to 2.28)