Red flags in back pain received further attention recently. A systematic review in the BMJ reported lack of supporting evidence for many accepted red flag symptoms in diagnosis of fracture or malignancy.
An earlier Cochrane systematic review, also from the University of Sydney, had similar conclusions for identification of vertebral fractures using red flags. Williams et al. concluded that available evidence does not support the use of many red flags to specifically screen for vertebral fracture in patients presenting with low back pain. Many red flags were found to have high false positive rates, potentially leading to unnecessary investigation. 2
The red flags most useful for identification of fractures were: older age, prolonged use of corticosteroids, severe trauma and presence of a contusion or abrasion. Combinations of red flags raised the probability of fracture. The red flag with the highest probability of helping to identify spinal malignancy was that of a past history of malignancy.
The authors suggest revision of many current guidelines may be required.