A comparison of economic and social reward in patients with chronic nonmalignant back pain.

Abstract

Patients with chronic nonmalignant back pain are often exposed to multiple sources of economic and social reward. At issue in the present study was whether these rewards are 1) correlated with similar or dissimilar outcome variables and 2) able to account for unique variance in regression models of illness behavior. A 2 x 2 factorial design was used in which patients were retrospectively assigned to one of four independent groups: low economic/low social reward, low economic/high social reward, high economic/low social reward, and high economic/high social reward. Of 265 consecutive patients enrolled at a tertiary pain service, 75 met eligibility criteria and had chronic nonmalignant back pain. Preexisting differences in health status were not associated with differences in illness behavior or pain ratings. With social reward held constant, patients in the high economic reward group missed more days from work (p < .005), had more domestic disability (p < .05), and were more depressed (p < .05) than patients in the low economic reward group. With economic reward held constant, patients in the high social reward group missed more days from work (p < .05), had more domestic disability (p < .01), and were more depressed (p < .01) than patients in the low social reward group. Unlike patients in the high economic reward group, however, patients in the high social reward group had higher levels of pain (p < .05) and more nonspecific medical complaints (p < .01). Economic and social rewards were both associated with increased disability and depression, but only social rewards were associated with increased symptom reporting. Exposure to economic and social rewards may account for unique variance in illness behavior that cannot be explained by differences in medical diagnosis, symptom duration, pain intensity, depression, or somatization.