The development of a Somatic Amplification Rating Scale for low-back pain

The development of a new scale, the Somatic Amplification Rating Scale (SARS), for the quantification of exaggerated (nonorganic) motor, sensory, and pain responses occurring during a standardized physical examination is described. This 13-item scale, partially based on a measure of nonorganic physical signs developed by Waddell et al, was administered to 127 low-back pain patients at an outpatient pain center. It was determined that the 13-item scale could be shortened to seven items with improved ease of administration and little loss of reliability and validity. Interrater reliability of the finalized seven-item scale was excellent (R = 0.93). Finally, it was determined that patients with high SARS scores were significantly more likely to be receiving workers' compensation benefits and to endorse physical symptoms with greater intensity on psychologic testing (Symptom Checklist 90).