Racial differences in the use of lumbar spine radiographs - Results from the Veterans Health Study

Study Design. We analyzed data from the Veterans Health Study, a longitudin al study of male patients receiving VA ambulatory care. Objective. To determine whether clinical differences and/or race account fo r disparities between white and nonwhite patients in the use of lumbar spin e radiographs. Summary and Background Data. Four hundred one patients with low back pain ( LBP) receiving ambulatory care services in four VA outpatient clinics in th e greater Boston area were followed for 12 months. Methods. Participants were mailed the Medical Outcome Study Short Form Heal th Survey (SF-36) and had scheduled interviews that included the completion of a low back questionnaire, a comorbidity index, and a straight leg raisi ng (SLR) test. Using self-reported racial data, patients were grouped as wh ites (315 patients) and nonwhites (among whom 22 were black, 4 nonwhite His panics, and 1 other race). Results. Nonwhite patients had lumbar spine films more often (13 of 27, 48% ) than white patients (87 of 315, 27%)(P = 0.02). Nonwhite patients had hig her pain intensity scores than white patients (63 +/- 21 vs. 48 +/- 21, P < 0.01) and were more likely to have radiating leg pain (20 of 27, 76%; comp ared with 171 of 315, 55%; P = 0.01) than white patients. Nonwhite patients had worse physical functioning (P = 0.01), general health perception (P = 0.05), social functioning (P = 0.02), and role limitations because of emoti onal problems (P < 0.01). At higher LBP intensity level, nonwhite patients received more lumbar spine films (20 of 27, 74%) than did white patients (1 55 of 315, 50%)(P < 0.01). Among patients with positive SLR test, nonwhite patients also had lumbar spine films more often (5 of 22, 23%) than white p atients (29 of 315, 11%) (P < 0.01). However, after adjusting for multiple clinical characteristics, race was no longer found to be an independent pre dictor of lumbar spine radiograph use. A positive SLR test remained to be a ssociated with higher radiograph use, whereas better mental health status w as associated with lower radiograph use. Conclusions. There was greater use of lumbar spine radiographs by nonwhite patients compared with white patients. This remained true when patients wer e subcategorized by severity of LBP or SLR test. However, race had no influ ence when multiple clinical characteristics of the patients were controlled for simultaneously. This study demonstrates the importance of careful and comprehensive case-mix adjustment when assessing apparent differences in th e use of medical services.