Introduction: Over the last decades, psychosocial factors were identified by many studies as significant predictive variables in the development of disability related to common low back disorders, which thus contributed to the development of biopsychosocial prevention interventions. Biopsychosocial interventions were supposed to be more effective than usual interventions in improving different outcomes. Unfortunately, most of these interventions show inconclusive results. The use of screening questionnaires was proposed as a solution to improve their efficacy. The aim of this study was to validate a new screening questionnaire to identify workers at risk of being absent from work for more than 182 cumulative days and who are more susceptible to benefit from prevention interventions.
Methods: Injured workers receiving income replacement benefits from the Quebec Compensation Board (n = 535) completed a 67-item questionnaire in the sub-acute stage of pain and provided information about work-related events 6 and 12 months later. Reliability and validity of the 67-item questionnaire were determined respectively by test-retest reliability and internal consistency analysis, as well as by construct validity analyses. The Cox regression model and the maximum likelihood method were used to fix a model allowing calculation of a probability of absence of more than 182 days. Criterion validity and discriminative capacity of this model were calculated.
Results: Sub-sections from the 67-item questionnaire were moderately to highly correlated 2 weeks later (r = 0.52-0.80) and showed moderate to good internal consistency (0.70-0.94). Among the 67-item questionnaire, six sub-sections and variables (22 items) were predictive of long-term absence from work: fear-avoidance beliefs related to work, return to work expectations, annual family income before-taxes, last level of education attained, work schedule and work concerns. The area under the ROC curve was 73%.
Conclusions: The significant predictive variables of long-term absence from work were dominated by workplace conditions and individual perceptions about work. In association with individual psychosocial variables, these variables could contribute to identify potentially useful prevention interventions and to reduce the significant costs associated with LBP long-term absenteeism.