Can guidelines impact the ordering of magnetic resonance imaging studies by primary care providers for low back pain?
OBJECTIVE: To compare primary care providers’ (PCPs’) use of lumbar spine magnetic resonance imaging (MRI) studies and surgical referrals for patients with low back pain (LBP) before and after dissemination of the 1994 Agency for Healthcare Policy and Research (AHCPR) LBP guidelines. DESIGN: Retrospective cohort study. PATIENTS AND METHODS: Computerized audits identified patients with LBP evaluated by PCPs in 1994 or 1996 at a university-affiliated Veterans Affairs medical center who had an MRI order and/or a surgical referral. Research assistants recorded patients’ demographic characteristics, LBP-related symptoms, and whether the PCP ordered an MRI and/or a surgery consult. For patients referred to surgery without an MRI, subsequent MRI orders by surgeons were recorded. We compared patient characteristics and utilization patterns for 1994 and 1996 and identified independent predictors of MRI orders. RESULTS: PCPs saw 279 and 261 patients with LBP in 1994 and 1996, respectively. An al