Jeremy T. Rohrlich

Abstract
Background Context
Nonorganic low back pain is common in the Worker’s Compensation (WC) population. Consults with specialists constitute an unnecessary cost to the system, and a means of screening for these patients is necessary.

Purpose
The purpose of this study is to design easily identifiable criteria to help identify which Worker’s Compensation patients are likely to have nonorganic pain.

Study Design/Setting
The study design involved a retrospective chart review of WC patients with low back pain seen in consultation by a single spine surgeon over a 2-year period of time at a University medical center.

Patient Sample
127 WC patients with low back pain were seen in consultation by a single spine surgeon over a 2-year period of time. All were referred for surgical evaluation. Potential risk factors for nonorganic pain were identified. These included: alleged injury in multiple bodily areas; presence of concomitant cervical and/or thoracic complaints; initial presentation to chiropractor; mechanism of injury including slip and fall or lifting of a patient; number of prior IMEs performed; presence of psychiatric diagnosis; areas of pain different from first report of injury; >13 months between evaluations; occupation as a healthcare employee; presence of legal representation; amount of time off work; current work status (working or disabled); and number of prior WC claims.

Outcome Measures
Outcomes measures included the number of Waddell’s signs and additional nonorganic/ inconsistent pain behaviors noted during the examination by the spine specialist. Nonorganic low back pain was defined as: 4 or more Waddell’s signs or 3 Waddell’s signs plus one additional inconsistent behavior.

Methods
A stepwise logistic regression was used to determine which of the risk factors were significantly associated with nonorganic pain, correcting for age and sex. We then used an analysis of deviance to determine which combination of factors could best differentiate patients with nonorganic findings. There were no sources of funding for this study or identifiable conflict of interest-associated biases.

Results
Factors which were significantly associated with nonorganic pain included: 1) mechanism of injury including slip and fall or lifting of a patient (OR=5.7, p=0.03); 2) alleged injury in >2 bodily areas (OR=4.2, p=0.02); 3) presence of concomitant cervical and thoracic complaints (OR=2.9, p=0.04); 4) initial presentation to chiropractor (OR=7.7, p=0.01); 5) back pain not listed on first report of injury (OR=3.3, p=0.04). Patients with 3 or more of these findings were found to be at very high risk for having nonorganic pain (>95%).

Conclusions
We found a significant association between certain easily identifiable criteria and nonorganic low back pain in a cohort of WC patients. These criteria included: mechanism of injury including slip and fall or lifting of a patient; 2) alleged injury in >2 bodily areas; 3) presence of concomitant cervical and/or thoracic complaints; 4) initial presentation to chiropractor; 5) areas of pain different from first report of injury. Over 95% of patients with 3 or more of these criteria were found to have nonorganic pain. This information may help the specialist and the WC provider identify patients at high risk for nonorganic pain thereby reducing unnecessary costs.

Abstract online:  http://www.sciencedirect.com/science/article/pii/S152994301301557X