Assessment of functional status, low back disability, and use of diagnostic imaging in patients with low back pain and radiating leg pain

We analyzed data from outpatients with chronic low back pain (LBP) in the Veterans Health Study (n = 563) to examine the relationship between localized LBP intensity and radiating leg pain in assessing patient functional status, low back disability, and use of diagnostic imaging. Based on the localized LBP intensity, the study subjects were divided into tertiles (low, moderate, and high intensity). The study subjects were also stratified by the extent of radiating leg pain. Using analysis of variance and multiple regression analysis, we compared the relative importance of localized LBP intensity and radiating leg pain in explaining the variability in the means of the SF-36 scales and low back disability days, and in the proportion of patients who had used diagnostic imaging. The results of the study indicate that measures of localized LBP intensity and radiating leg pain contribute separately to the assessment of patient functional status, low back disability, and use of diagnostic imaging. These results suggest that localized LBP intensity and radiating leg pain may represent two different approaches in assessing back pain severity. Future epidemiological and health services research should consider both measures in assessing the impact of LBP on patient functional status, low back disability, and use of diagnostic imaging. J CLIN EPIDEMIOL 52;11:1063-1071, 1999. (C) 1999 Elsevier Science Inc.