Red flags to screen for malignancy and fracture in patients with low back pain: systematic review

Abstract

Objective To review the evidence on diagnostic accuracy of red flag signs and symptoms to screen for fracture or malignancy in patients presenting with low back pain to primary, secondary, or tertiary care. Design Systematic review.Data sources Medline, OldMedline, Embase, and CINAHL from earliest available up to 1 October 2013.Inclusion criteria Primary diagnostic studies comparing red flags for fracture or malignancy to an acceptable reference standard, published in any language.Review methods Assessment of study quality and extraction of data was conducted by three independent assessors. Diagnostic accuracy statistics and post-test probabilities were generated for each red flag. ResultsWe included 14 studies (eight from primary care, two from secondary care, four from tertiary care) evaluating 53 red flags; only five studies evaluated combinations of red flags. Pooling of data was not possible because of index test heterogeneity. Many red flags in current guidelines provide virtually no change in probability of fracture or malignancy or have untested diagnostic accuracy. The red flags with the highest post-test probability for detection of fracture were older age (9%, 95% confidence interval 3% to 25%), prolonged use of corticosteroid drugs (33%, 10% to 67%), severe trauma (11%, 8% to 16%), and presence of a contusion or abrasion (62%, 49% to 74%). Probability of spinal fracture was higher when multiple red flags were present (90%, 34% to 99%). The red flag with the highest post-test probability for detection of spinal malignancy was history of malignancy (33%, 22% to 46%).Conclusions While several red flags are endorsed in guidelines to screen for fracture or malignancy, only a small subset of these have evidence that they are indeed informative. These findings suggest a need for revision of many current guidelines.

Red flags presented in current low back pain guidelines: a review

“…A recent paper summarizing two Cochrane diagnostic systematic reviews found nine studies evaluating the diagnostic accuracy of in total 29 red flags for fracture and 24 for malignancy [8]. There were differences in the red flags that demonstrated diagnostic utility and those endorsed by guidelines.…”

“…For malignancy, the systematic review concluded that only 'history of cancer' is based on acceptable validity; it increases the probability of having cancer from 0.7 % (pretest) to 33 % (95 % CI 22-46 %) [8]. Nevertheless, this conclusion is based on one study set in primary care and another in an emergency department where 36 % of patients were referred to because of a significant trauma [40,41].…”

“…According to the systematic review, the red flags 'severe trauma', 'use of corticosteroids', 'older age' and 'presence of a contusion or abrasion' each increased the probability of a fracture from 4 % (pre-test) to between 9 and 62 % [8]. Three of these red flags were most often mentioned in the guidelines, but one ('presence of a contusion or abrasion') was absent from all guidelines.…”

“…Serious pathology in patients presenting with low back pain includes malignancy, spinal fractures, cauda equina syndrome (CES), infection or aortic aneurisms. Spinal malignancy and vertebral fracture are the most frequent serious pathologies of the spine [8]. However, the absolute magnitude of occurrence may be regarded as rare.…”

Identifying back pain subgroups: developing and applying approaches using individual patient data collected within clinical trials

“…The scoring for each item ranges from 0 (less than 1 day per week) to 3 (5 to 7 days per week). The scoring for items 2, 6,7,12, 14,16,18,20,21 and 23 is reversed.MZDI score = sum of all items.The range of the score is from 0 to 69 where higher score indicates more depressed. …”