Evidence & Methods
Studies to identify factors associated with failure to return to work continue to be explored. Much of the focus has been on psychosocial factors and less on clinical factors.
Using data from a randomized trial, the authors found that many of the well-known psychosocial factors associated with failure to return to work in patients with isolated low back pain were further supported in this study. They also found that age was an independent predictor of poor outcomes in subjects with demonstrated radiculopathy and root compression. In subjects with demonstrated root compression and radiculopathy it appeared the psychosocial factors were less significant predictors of outcome than these appeared to be in subjects with nonspecific pain low back syndromes.
The study supports previous assumptions; and, appropriately, several of the study's limitations are described by the authors. The study also emphasizes that psychosocial factors may be more consistently important in patients in whom the only findings are common degenerative changes without radiculopathy.
—The Editors
The outcomes are interrelated, but change in one outcome may occur without influencing the other outcomes. For instance, in LBP patients who felt at risk of developing disability, cognitive intervention had impact on sick listing the following year but no influence on pain or disability in the first place [3]. Four years later, however, both pain and disability were reduced in the intervention group compared with the control group [4].
A recent systematic review included 16 publications to identify predictors for function-related outcome [5]. The following variables were found to be of some importance: intensity of pain, radiating pain, disability, fear avoidance, number of pain sites, somatization, depression, perceived risk of recovery, age, gender, income, psychological and physical job demands, and school education. However, the studies were very heterogeneous, and the published instruments had only moderate ability to predict or explain function-related outcome.
Multiple pain sites and widespread pain have been identified as risk factors in LBP [5], [6]. Nevertheless, diffuse tenderness has not been investigated as a risk factor for pain and disability. Widespread pain may be estimated clinically by counting the number of tender points, a method for estimating diffuse tenderness. Many tender points are a sign of diffuse mechanical hyperalgesia, which is a sign of sensitization of the nociceptive system [7], [8], [9].
Most studies of risk factors have only included nonspecific LBP with or without leg pain. The present study also included patients with radiculopathy because of disc herniation or spinal stenosis.
The patients participated in a randomized clinical trial are reported elsewhere [10]. It was considered relevant to analyze the outcome as in cohort studies because there were no differences between the two intervention groups in terms of disability, pain, or RTW.
The purpose of the present study was to identify prognostic factors for disability and pain in sick-listed LBP patients and to look for differences between patients with and without radiculopathy; investigate, if the number of tender points was associated with disability and pain; and analyze, if RTW was more associated with change in disability than change in pain. RTW data are presented in detail elsewhere.
