Few patients with acute back pain in primary care have serious pathology

Clinical question How often are serious problems identified among patients with acute back pain seeking care from primary care physicians?

Bottom line In this prospective study of patients with acute low back pain seeking care from primary care physicians, approximately 1% had serious underlying pathology. Although one might question whether the diagnostic standard was rigorous enough, the true rate is nonetheless likely to be quite low. (Level of evidence = 2b)

Synopsis These Australian authors report on 1,172 consecutive patients older than 14 years with acute low back pain who sought care from a primary care physician. Each patient was asked about the presence of any of 25 (that's right: twenty-five!) “red flags”; that is, symptoms associated with serious causes of back pain such as cancer, cauda equina syndrome, infection, or fractures. The primary care physicians in this study were trained to use a clinical decision guide to categorize patients into 1 of 3 categories: simple backache, nerve root compromise, or suspected serious spinal pathology. Not all patients underwent radiography. The “gold standard” was based on clinical follow-up 12 months after the initial consultation. Additionally, the patients were evaluated by phone 6 weeks, 3 months, and 12 months after the initial visit. At these interviews, the patients were asked if they had been given a diagnosis of a fracture, infection, cancer, or arthritis. A study rheumatologist independently evaluated 20% of all patients (chosen randomly) and also evaluated any patient suspected of having a serious cause of their pain. Although 80% of patients reported having at least one “red flag,” only 0.9% of the patients had confirmed pathology: eight patients with fracture, one with cauda equina syndrome, and two with inflammatory arthritis. None of the patients had infection or cancer.

Henschke N, Maher CG, Refshauge KM, et al. Prevalence of and screening for serious spinal pathology in patients presenting to primary care settings with acute low back pain. Arthritis Rheum. 2009;60(10):3072-3080.