Effects of time-limited vs unlimited compensation on pain behavior and treatment outcome in low back pain patients.

A common theme in the pain literature is that worker's compensation reinforces pain behavior and adversely influences treatment outcome of chronic pain patients. This study compared 110 chronic low back pain males divided into three groups: 44 receiving no compensation, 27 receiving time-limited worker's compensation, and 39 receiving unlimited social security disability benefits. All patients participated in a multimodal treatment program (e.g. nerve blocks, transcutaneous electrical nerve stimulation, relaxation training, biofeedback). Physician ratings of pain behavior and self-report measures of pain characteristics, activity level, and medication intake were gathered pretreatment; self-report measures were collected again approximately one year following treatment. The results showed disability patients to have a higher percentage of physician rated symptom dramatization and pain behavior and a greater usage of medication compared with the non-compensation and time-limited worker's compensation patients. At follow-up, no between group differences were found on measures of pain intensity, medication usage and activity. In general, however, more worker's compensation and non-compensation patients who were initially not working had returned to work at the time of follow-up compared with the disability patients. These results suggest that time-limited compensation may not affect treatment outcome or interfere with return-to-work chances while unlimited compensation may adversely influence the probability that patients will return to work. These findings support the notion that worker's compensation patients receiving time-limited financial benefits do not necessarily represent a 'problem' subgroup of chronic pain patients.