PATIENT CHARACTERISTICS ASSOCIATED WITH DIAGNOSTIC-IMAGING EVALUATIONOF PERSISTENT LOW-BACK PROBLEMS

Study Design. Post hoc analysis of data from the National Low Back Pai n Study, a prospective observational multicenter study of patients ref erred for the evaluation and treatment of persistent low back problems . Objective. To identify patient characteristics associated with use o f particular diagnostic imaging examinations in patients with persiste nt low back problems. Summary of Background Data. The Agency for Healt h Care Policy and Research clinical practice guidelines on low back pr oblems suggest that the use of particular diagnostic imaging tests for a given patient should be based on specific characteristics of that p atient. Methods. Use of diagnostic imaging examinations in 2,374 patie nts with persistent low back problems who were enrolled in the Nationa l Low Back Pain Study from 1986 to 1991 was analyzed. Stepwise logisti c regression was used to identify patient characteristics that distinq uish between enrollees who underwent particular imaging studies. Resul ts. Characteristics that distinguished patients who had undergone magn etic resonance imaging from those who had received only lumbo-sacral s pine radiographs included higher socioeconomic status, greater resourc e use in the preceding 12 months, more functional impairment, presence of sciatica, and presence of neurologic signs/symptoms suggestive of nerve root compromise. Suspected soft tissue involvement was character istic of enrollees who had undergone magnetic resonance imaging, where as suspected structural involvement characterized patients who receive d noncontrast computed tomography. Only nonclinical factors, such as h igher annual household income, disability compensation, and male gende r distinguished enrollees who had undergone both magnetic resonance im aging and computed tomography-myelography from those who received only computed tomography-myelography. Conclusion. Particular patient socio economic and clinical characteristics are associated with receipt of s pecific imaging studies in evaluation of persistent low back problems.