Why was this study done?
The researchers wanted to determine if workers with low-back pain could be classified into different groups according to risk factors associated with time off work. If so, different interventions, or courses of action, could be more closely tailored to an individual worker’s condition.
How was the study done?
The study looked at 442 workers with low-back pain who had filed lost-time injury claims with Ontario’s Workplace Safety and Insurance Board (WSIB). Of these, 259 had returned to work one month after injury. These were classified as the low risk group. The remaining 183 were called the high risk group. All 442 workers were scored according to risk factors associated with time off work: pain, disability, fear of pain and reinjury, physical job demands, people-oriented workplace culture, workplace disability management practices and depressive symptoms.
What did the researchers find?
Based on the risk-factor scores, researchers identified three groups of workers with low-back pain who were still off work at the one-month mark. They also suggested the type of intervention that might benefit each most.
Class 1 – Workplace factors: These workers had pain and disability scores similar to those who had already returned to work. However, their scores for disability management practice and people-oriented culture were much worse. Interventions that address workplace practices and work environment might benefit these workers the most.
Class 2 – Positive workplace, but greater back pain: These workers had the highest scores with respect to disability management practices and people-oriented culture, even higher than those who had already returned to work. However, their pain and disability levels were relatively high. These workers might benefit most from interventions that target back pain, such as exercises. They might also benefit from assuring health-care providers who communicate with supervisors to set up return-to-work programs.
Class 3 – Multiple factors: These workers scored the worst in all areas except disability management practices and workplace culture. However, these scores were also relatively poor. Their levels of depressive symptoms were much higher. Multidisciplinary programs that pay particular attention to workplace and psychological issues may benefit these workers. Approaches such as problem-solving training, coping skills development and stress management might all be helpful.
What are some strengths and weaknesses of the study?
The study confirmed an earlier approach, based on risk factors, that identified distinct groups of workers with low-back pain who needed potentially different kinds of help to recover.* A limitation of this study is that risk factors were determined based exclusively on injured workers’ self-reported information.
*See Shaw WS, Linton SJ, Pransky G. Reducing sickness absence from work due to low back pain: How well do intervention strategies match modifiable risk factors? Journal of Occupational Rehabilitation, 2006; vol. 16, no. 4, pp. 591-605.