A prospective study of Waddell signs in patients with chronic low back pain. When they may not be predictive.

STUDY DESIGN

Analysis of the treatment-outcome predictive power of Waddell signs by evaluating them before and after functional restoration, with assessment of 1-year socioeconomic outcomes.

OBJECTIVE

To evaluate the presence of Waddell nonorganic signs in a group of patients with chronic low back pain presenting for functional restoration, and to determine whether they were predictive of treatment success of failure.

SUMMARY OF BACKGROUND DATA

Waddell has described "nonorganic" physical signs in patients with chronic low back pain indicative of somatization. Other researchers have correlated high Waddell scores with psychosocial barriers that required additional consultation, and have suggested that diminution of a Waddell score during physical rehabilitation is predictive of subsequent therapeutic success.

METHODS

Total positive Waddell signs score and individual sign scores were assessed at initial presentation for functional restoration treatment and at discharge in a group of 50 patients with chronic low back pain (average length of disability = 17.9 months; average age = 38.5 years). Patients were then tracked and assessed with a 1-year follow-up structured interview to evaluate outcome variables such as return to work, work retention, re-injury rate, health utilization, and subsequent surgery.

RESULTS

Statistical analyses of these data revealed no significant associations between Waddell total positive score or changes in score and therapeutic success as measured by any of the behavioral outcomes such as return to work. Also, no predictive value was found for the individual positive signs of their changes and therapeutic success.

CONCLUSIONS

Although positive Waddell signs have been found to be predictive in patients with short-term chronic low back pain, the current results suggest that, in patients who have longer duration of pain and who undergo a comprehensive functional restoration program, these signs are not significantly prognostic. Because functional restoration is an interdiscipilinary approach that effectively manages somatization complaints in a consistent manner by all treatment personnel, such complaints do not create any major barriers to recovery. Therefore, although Waddell signs may be predictive of treatment outcome in less intensive rehabilitation programs, they do not provide any predictive power in a comprehensive functional restoration program, which has a basic goal of managing barriers to recovery in a clinically efficacious manner.